Science for South Africa
Volume 3 • Number 1 • 2006 R20
Academy of Science of South Africa
Messages from birds Members of the DST–NRF Centre of Excellence: Birds as Keys to Biodiversity Conservation at the Percy FitzPatrick Institute Listening carefully to learn from the world of birds 12
The birth of a black hole Martin Still Going back 12 billion years to the early Universe
Where are the fishes? Members of the South African Institute for Aquatic Biodiversity Marine life under threat ■ Coelacanth hide and seek
James Richard Stapley
The search for living fossils
■ Still counting
Finding and looking after fishes
Technology to track fish movements, Paul Cowley (p. 24) • A proudly South African Fish Community Index, Alan Whitfield (p. 25) • Citizen science – the East Coast Fish-Watch Project, Phanor Montoya-Maya, and Phil and Elaine Heemstra (p. 26)
South Africa into space ■ What does space do for you?
How we use it every day
Contents Volume 3 • Number 1 • 2006
Science news Andromeda’s rings of fire (p. 11) • The oldest fossil lamprey in the world (p. 11) 19
Bob Scholes, Arnold Schoonwinkel, and Hendrik Burger
Fact file Finding coelacanths (p. 19) • South Africa’s history in space (p. 33) Your Questions answered Laying waste to aliens? – Brian van Wilgen and Patricia Holmes
Books Forest Plants in the Forest and in the Garden
Viewpoint Can e-language-support really help? Beth Jeffery and Jano Jonker
■ Satellites of our own
Careers Work in conservation biology (p. 10) • Work in aquatic biodiversity (p. 28)
The S&T tourist Scientific visit to Grahamstown Cindy Fisher and Nomtha Myoli Must-sees in the heart of the Eastern Cape
Space platform for South Africa 44
Quest interview What is ‘quality’ furniture? – The Bakos brothers
Precious water, earth, and air Young people caring for the future
From fossils to stamps François Durand The Post Office celebrates the Cradle of Humankind
Letters to Quest Early South African birds • Why invest in big science?
Diary of events
Back page science • Mathematical puzzle
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Finding things F Reef scene, Sodwana Bay, Kwazulu Natal, with coachman (Heniochus acuminatus) above, halfmoon butterflyfish (Chaetodon lunula) in the middle, masked coachman (Heniochus monoceros) below, and sea goldies (Pseudanthias squamipinnis) scattered about the reef. Photograph: Dennis King SCIENCE FOR SOUTH AFRICA
Editor Elisabeth Lickindorf Editorial Board Wieland Gevers (University of Cape Town) (Chair) Graham Baker (South African Journal of Science) Anusuya Chinsamy-Turan (University of Cape Town) George Ellis (University of Cape Town) Jonathan Jansen (University of Pretoria) Colin Johnson (Rhodes University) Correspondence and The Editor enquiries PO Box 1011, Melville 2109 Tel./fax: (011) 673 3683 e-mail: firstname.lastname@example.org (For more information visit www.assaf.co.za and www.assaf.org.za) Advertising enquiries Barbara Spence Avenue Advertising PO Box 71308 Bryanston 2021 Tel.: (011) 463 7940 Fax: (011) 463 7939 Cell: 082 881 3454 e-mail: email@example.com Meg Kemp Subscription enquiries Tel./Fax: (012) 804 7637 or and back issues (011) 673 3683 e-mail: firstname.lastname@example.org or email@example.com
inding things so as to discover what we can about them is an important part of what scientists do. Not just any old things at random, but those that tell a story or convey a message, or indicate conditions that could have serious implications. Take the phrase ‘global biodiversity crisis’. Some people worry about the loss of species; others claim that there’s nothing to be anxious about. So, in this issue of QUEST, researchers working with birds (p. 3) – and others working with fish – explain what they’ve done to find out where South Africa’s birds (and fishes) are, how many there are, and what’s been happening to them. The natural environments of fishes are different so the processes of finding them are different too. How do you find coelacanths in deep underwater caves (p. 18)? How do you count fishes in estuaries and diagnose their state of health (p. 25)? How do you track their movements under water if you’re a person living in another element altogether (p. 24)? What do you make of an ancient fossil fish that’s found inland far from the coast (p. 11)? Fish and birds have suffered in recent times from the effects of human activities, and we can’t know the extent of the damage to ecosystems until we find (out) what’s left behind. Deciphering the messages of dwindling numbers, and quantifying the results of unsound fishing practices, can help with the serious planning that’s needed to avert disaster. Ecosystems affect people too, as the Youth report on the state of South Africa’s environment makes clear (p. 16). What happens to water, to the earth, and to the air is the legacy that young people will inherit, so they need to stay informed. Celebrating South African science is what we’re about. The Post Office is celebrating our palaeoanthropological heritage with a new set of stamps (p. 38); the country is preparing a national space platform that will offer affordable satellite facilities to serve our special needs (p. 31). Astronomers are taking other kinds of journey into space to understand what’s been happening elsewhere in the Universe – finding gamma-ray bursts uncovers the story of black holes and the cosmos as it was just 1.7 billion years after the Big Bang (p. 12); finding ‘rings of fire’ within the Andromeda Spiral Galaxy brings astonishing evidence of a galactic collision just 200 million years ago, when dinosaurs roamed the Earth (p. 11). Finding for a purpose is at the heart of so many researchers’ endeavours. The articles on these pages tell the stories of what scientists do to find what they find, to document and analyse it, and to discover what it all means.
© 2006 Copyright Academy of Science of South Africa Published by the Academy of Science of South Africa (ASSAf) PO Box 72135, Lynnwood Ridge 0040, South Africa (011) 673 3683 Permissions Fax: e-mail: firstname.lastname@example.org Subscription rates (4 issues and postage) (For subscription form, other countries, see p.48.)
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Elisabeth Lickindorf Editor – QUEST: Science for South Africa Join QUEST’s knowledge-sharing activities Write letters for our regular Letters column – e-mail or fax your letter to The Editor. (Write QUEST LETTER in the subject line.) ■ Ask science and technology (S&T) questions for specialist members of the Academy of Science to answer in our regular Questions and Answers column – e-mail or fax your questions to The Editor. (Write QUEST QUESTION in the subject line.) ■ Inform readers in our regular Diary of Events column about science and technology events that you may be organizing. (Write QUEST DIARY clearly on your e-mail or fax and provide full and accurate details.) ■ Contribute if you are a specialist with research to report. Ask the Editor for a copy of QUEST’s Call for Contributions (or find it at www.assaf.co.za or www.assaf.org.za), and make arrangements to tell us your story. To contact the Editor, send an e-mail to: email@example.com or fax your communication to (011) 673 3683. Please give your full name and contact details. ■
Messages from birds
Below: The Centre is involved in groundbreaking research on ways in which the environment influences embryonic development in birds. South African species differ widely in their rates of embryonic development. The Cape grassbird (Sphenoeacus afer), in the nest below, is one of the slowest.
Members of the DST–NRF Centre of Excellence: Birds as Keys to Biodiversity Conservation at the Percy FitzPatrick Institute explain how studying birds can help us to understand the value – and complexities – of conserving biodiversity.
Photograph: Anna Chalfoun
iodiversity extends across all forms of life – from the microscopic genes in individuals to the species and ecological processes of entire ecosystems – bringing benefits too great and too wide-ranging to calculate precisely. What principles guide the conservation of biodiversity? And how can we make sure we don’t lose this great wealth through carelessness or ignorance? Birds offer many answers, as research at the DST–NRF Centre of Excellence at the Percy FitzPatrick Institute repeatedly shows. A century and a half ago, birds helped Charles Darwin to understand the principle of natural selection that underpins the theory of evolution1. Today, as a much-studied group, birds offer early warning signals of environmental change. Knowing how to interpret messages from the world of birds – and reacting in the right ways – can help us to prevent disaster and to find out how best to build up our remarkable environmental heritage. Top left: The face of a black sparrowhawk (Accipiter melanoleucus). This bird has expanded its range with the growth of large alien trees, in which it nests in normally treeless habitats. Photograph: Odette Curtis Below left: Sociable weaver (Philetairus socius) in a net. These birds breed cooperatively in large communal nests in the Kalahari. In a long-term study, all birds in a set of colonies were caught in mist-nets to be ringed for individual identification and monitoring. Photograph: Claire Spottiswoode
1. Birds were pivotal to the development of much biological theory. Charles Darwin’s observations of variation in beak shape and size among what are now known as Darwin’s finches of the Galapagos Islands, for instance, were a watershed in the development of his theory of evolution. Another example is the theory of island biogeography developed by Robert MacArthur and Edward Wilson in 1963, which holds that the diversity of species on any island is determined by both its size and distance from the mainland. Fewer species are supported on smaller islands because the probability of extinction is greater, and fewer species are supported on islands that are very far from a mainland, because the probability of immigration is lower.
Above: Sociable weavers (Philetairus socius) use large nest structures – like apartment blocks! – in which colonies of up to 300 birds occupy separate chambers. In many instances, young birds from previous broods refrain from independent breeding and help their parents raise new young. These nests give shelter during frosty winter nights and protect the birds from summer heat. Photograph: Peter Ryan
DST/NRF Centre of Excellence: Birds as Keys to Biodiversity Conservation at the Percy FitzPatrick Institute* South Africa needs to industrialize further – to generate income to improve its citizens’ well-being – while actively maintaining and protecting its sources of wealth, including its diverse ecological heritage. This centre of excellence is training biological scientists and conservation managers. Focusing on the world of birds, it is growing the body of scientific knowledge of the patterns and processes that sustain and influence biodiversity, and involving itself actively in programmes with direct, on-the-ground effects on biodiversity. Its research has two broad, interlinking themes. The first, ‘Understanding biodiversity’, examines the composition and origins of biodiversity and the ways in which relationships between living organisms and their environments influence the functioning of biological systems. The second, ‘Maintaining biodiversity’, builds on that theoretical foundation, examining ways in which people alter environments and influence the ways in which biological systems work. Managing biodiversity effectively means integrating these themes, so as to help to develop strategies for dealing with human impacts and for stemming the country’s critical loss of biodiversity. The Centre is expanding the base of conservation-related science. Studies range from detailed research on single species, through population and community ecology, to broad-scale work on landscape ecology, and they tackle issues such as conservation problems of individual species and communities, regional impacts of climate change, and the design of nature reserves. * The Centre is hosted by the University of Cape Town, with collaborating partners at the universities of Pretoria, Stellenbosch, and the Witwatersrand. Much of the work is undertaken with partners in other university departments, governmental organizations, and NGOs.
For details visit http://web.uct.ac.za/depts/fitzpatrick/
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Messages from birds altering environments. It also gives an idea of their ability to survive, as people transform landscapes and fragment natural habitats.
Insights from birds The range of biodiversity brings great advantages. People can exchange sequences of DNA among species in genetic engineering, for instance. And we’ve always depended on the ecosystem processes that deliver clean air and water, and on the buffers that protect communities against natural disasters2. South Africa has the world’s third-highest national biodiversity and it’s unique in being home to three biodiversity hotspots – fynbos, succulent Karoo, and Pondoland. These attractions appeal to tourists and bring a wealth of natural products, such as timber, thatch, and medicines from indigenous plants. They also confer the responsibility to catalogue and manage our biodiversity in a sustainable manner. Insights come from studying birds, molecules, and evolutionary patterns. Knowing how animals evolved and migrated in response to largescale environmental changes of the past helps in predicting how they could react in future. Understanding these things is crucial for assessing ways in which climate change might affect the ability of plant and animal communities to adapt to Top: Sunbirds are in general sexually dimorphic, with the male having metallic colouration and the female being drab. The female collared sunbird (Anthreptes collaris) is one of the few exceptions, as she too has some metallic colours on her head and back. Sunbirds feed on nectar from flowering plants, and are important pollinators. Photograph: Peter Ryan Middle: Painting (by Jon Fjeldså) of the eastern double-collared sunbird complex (Nectarinia mediocris) of Africa, which featured as the cover page of The Auk (July 2004). Below: The golden-winged sunbird (Nectarinia reichenowi) is one of many African species of sunbird. Species diversity in sunbirds mirrors that of other montane bird groups, which makes them an ideal group for studying the evolutionary processes that have generated high species diversity among montane birds in general. Photograph: Rauri Bowie
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Past evolutionary patterns To study evolutionary processes of the past, Rauri Bowie travelled to remote, isolated African rainforests in pursuit of sunbirds, a diverse group of small, nectar-feeding birds. He has examined variations in the sequence of DNA in the genes of different sunbird species and also in the genes of different populations of the same species. His results have indicated evolutionary processes that, over many millions of years, generated the diverse group of 82 species of sunbird on the African continent today. These same evolutionary processes very likely apply in the same way to other groups of birds, not to mention many groups of plants and animals. A 5 000-km chain of mountains runs along Africa’s east coast from Ethiopia to South Africa, with additional isolated mountain chains to the far west in Angola and Cameroon. In the tropics, only a few scattered areas are high enough (at altitudes above 1 800 m) to experience the cool temperatures and abundant rainfall that the growth of montane3 forests requires. Further south, however, latitude compensates for altitude, allowing montane-forest animal communities to reach sea level in South Africa. Some of these montane habitats are within sight of each other, while others are separated by hundreds of kilometres. Yet the lowland gaps between the mountains in these areas seem to act as barriers, preventing the movement of animal species (as well as of plants) from one highland to another, and confining breeding ranges to isolated, high-altitude habitats. Nearly 300 African bird species – many of them among the continent’s rarest – breed at altitudes above 1 800 m. Some are restricted to a single mountain range with populations that may total fewer than 2 000 individuals, so studying them is a high conservation priority. Other species occur on multiple mountain ranges, even though there are often huge distances between populations of the same species occupying some of the most isolated forests. Do the birds fly between mountain ranges and in this way connect very isolated populations? Or are these populations the isolated relicts of what was once a broader, more continuous distributional range from a far-off time when the climate was different? We use information in the genes of birds to tackle this question. Small differences in DNA among individuals and populations record the history of how animals bred with each other, how they moved amongst areas, and how changes in the environment affected them. Bowie’s research suggests that 2. A recent, forceful example of buffering comes from the assessment of coastlines after the Asian tsunami of December 2004, which found that coastal vegetation such as mangroves and beach forests helped to provide protection and reduce effects on adjacent communities. Tsunami damage was greatest in areas where mangroves and forests had been cleared. 3. Montane forest is forest growing on shallow, rocky, well-drained soils on mountain slopes.
Messages from birds
temperature and rainfall changes during the past three million years caused the montane forests repeatedly to contract and expand. In colder, wetter periods, montane forests expanded in area and connected formerly isolated patches. During warmer, drier periods, these forests contracted again, cutting the connections between montane communities. Genetic evidence shows that some populations of what till now have been regarded as a single species remained isolated for so long that they underwent enough genetic divergence to be reclassified as distinctly different species. Conservation ‘accounting’ mainly uses species as a unit of measure, and the relative abundance of a species is often used to prioritize a particular species for conservation action. So the recognition of one bird species occurring on five isolated mountains, as distinct from five bird species each restricted to one mountain, has different and far-reaching conservation implications. Researchers are now extending this type of investigation to other bird families. Hunting birds Through applied population genetics we’re able to estimate dispersal rates and the extent to which a species is isolated. One example concerns the Namaqua sandgrouse (Pterocles namaqua), which is hunted commercially4. These nomadic birds range widely across southern Africa and migrate between breeding and wintering quarters. In some years, sandgrouse visit a site in their tens of thousands, and in the following year there may be virtually none. To find out why, researchers compare the numbers of mutations in DNA sequences of different individuals. Do the birds move among regions and breed freely with birds in other regions? Or do individuals of different populations mix when they’re not breeding, and then return to a particular region to breed so that different populations occupy distinctly different breeding regions? Identifying the population of origin of overwintering birds helps researchers to establish what proportion of the total species population is found at over-wintering sites – which is where commercial hunting typically occurs. Knowing how breeding birds move among regions is an important guide for managing bird populations in the interests of long-term sustainable hunting. Cooperation vs conflict How do physical and social environments influence the ways in which individual animals survive and reproduce? Evolutionary ecologists keep searching for answers. Ultimately, the health of populations boils down to relative levels of survival and reproduction. These can vary among individual animals within a species according to different environments. So understanding the reasons helps us to determine what might happen to 4. Commercial hunting of Namaqua sandgrouse is typically for sport. The proceeds benefit the landowner (providing an additional source of revenue on a farm) as well as the hunting operator.
Above: Tracking ground hornbills by radio. Researchers scan the adjoining bush from a field vehicle sponsored by DOW Chemicals, to locate a ground hornbill tagged with a lightweight radio transmitter. VHF transmitters are used to locate the birds for general observation, while sophisticated GPS transmitters download hourly positional fixes of birds, carrying them via the ARGOS satellite system. We need to retrace the movements of wild ground hornbills accurately to understand how these birds use their habitat and interrelate with neighbouring groups. Photograph: Morné du Plessis Top right: Two nature-reserve workers fit an artificial nest into the boughs of a large tree. Ground hornbills use large tree cavities for breeding and, to help them, 36 artificial nests have been set up over the Klaserie, Timbavati, and Umbabaat private nature reserves, along the western boundary of the Kruger National Park. Since 2001, more than 90% of all ground hornbill breeding attempts in this area have taken place in these artificial nests. Photograph: Yuval Erlich Above right: Cage and dummy birds used in hornbill capture. To understand the demography of long-lived ground hornbills, we need to be able to identify individuals. To ring them and fit them with a radio transmitter, researchers use a large trap with an automated door. Models of dummy birds inside attract the territorial wild birds. Photograph: Morné du Plessis
A ‘molecular clock’ for evolutionary time Genetic analyses help to retrace the ‘footprints’ of bird species and their population histories. A blood sample is taken from a bird and a complex toolkit of molecular methods is used to isolate and sequence the DNA of the individual. This process yields a sequence of DNA for a particular collection of genes. Changes in the DNA sequence among individuals represent chance mutations that make different versions of the gene but that allow the gene to perform its normal function. As individuals breed, they pass these changes on to their offspring, and, through sexual reproduction, a mixture of changes occurs. Chance mutations accumulate over time, possibly at a measurable rate, so comparing the number of changes among individuals of different populations may indicate for how long they’ve been isolated from one another. This relationship between mutations and evolutionary time is called a ‘molecular clock’. The process that defines the relationship is evolutionary change. Right: Taking a blood sample from one of southern Africa’s smallest birds, the Cape penduline-tit (Anthoscopus minutus).
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Messages from birds ▲
Top: Pied babblers (Turdoides bicolor) hop on a scale to be weighed in return for a food reward in a field study of cooperative breeding. Habituating wild birds to the close presence of humans gives researchers a unique window onto their social habits. Photograph: Amanda Ridley
Above: Grooming helps to cement social bonds between individuals. An adult pied babbler (left) pauses while grooming a juvenile. Photograph: Amanda Ridley
Right: The Agulhas long-billed lark (Certhilauda brevirostris), a restrictedrange endemic, is confined to a maximum range of 15 000 km2 on the Agulhas Plain in the Western Cape. Credit: Peter Ryan
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animal populations when people alter their environments in particular ways. Evolutionary ecologists also consider how different species evolved as they adapted to changed conditions. Southern Africa is rich in bird species that live in cooperative family groups. This type of sociality (known as ‘cooperative breeding’) comes about when a dominant breeding pair is joined by one or more subordinate ‘helpers’, to assist the breeding pair in cooperative activities such as defending the group’s home territory, raising young birds, and watching out for predators. Such subordinates normally give up the opportunity to breed themselves, and, instead, help to look after the young of the breeding pair. This behaviour seems to challenge evolutionary theory, which predicts that individuals should follow more selfish breeding strategies to maximize the number of direct descendents that they can produce during their lifetime. But subordinate individuals adopt cooperative strategies when their opportunities for independent breeding are restricted too much by their environment and when the benefits of group living are attractive enough. Amanda Ridley studies cooperative breeding in pied babblers (Turdoides bicolor) in the Kalahari savannah. To observe the birds at close quarters, she needed to become an extended member of the family group. So, in mid-2003, she began to spend weeks patiently following groups around, flicking a tasty mealworm treat to any bird that approached her. The breakthrough came after about eight weeks, when the first young left their nests. More confiding than the adults – and happy to receive a free snack – their fearless curiosity encouraged the adults to become less wary. Slowly, the birds started seeing Ridley and her research assistants as benign hangers-on. Since then, researchers have been able to arrive in the group’s territory at first light, whistle to attract the group to them, and hand out small food rewards to individuals that hop on a portable scale to be weighed. They follow the group of birds around for the rest of
the day to observe their social interactions. Each individual is weighed at the beginning and end of each observation period, to inform researchers about the costs of breeding and dispersal (such as weight loss or the increased risk of predation for a lone individual), the way in which the young birds develop, and the effects of body weight on behaviour. Weight is a good indicator of physical condition and, often, of a bird’s life-history. Heavy individuals tend to win more fights for dominance, for example, or succeed in gaining a position in a new group. Once they’re dominant, heavy birds tend to stay dominant for longer than their lighter counterparts; their offspring tend to be heavier at fledging and more likely to survive into adulthood. For example, in the bird population studied, the group with the heaviest breeding pair produced 13 offspring that survived to independence over the past three years, compared with an average of 7.2 offspring for all the other groups in the study population. Heavy offspring also have higher foraging success once the adults stop feeding them, which may buffer them against weight loss over the dry winter period when food is scarce. Pied babblers live in groups of 3–14 adults, which occupy year-round territories centred on river-beds lined with camel-thorn trees. Group size has a lot to do with survival and breeding success. Very small groups risk being overrun and evicted by large neighbouring groups. Also, small groups have few helpers, so they raise fewer young to independence. But very large groups become unstable, and greater conflicts of interest among group members lead to eviction, emigration, and loss of breeding productivity. The most productive group size for this species is around 4–6 adults. Hierarchies of dominance determine breeding status. Adolescent pied babblers play-fight regularly, grappling and tumbling with each other on the ground. Through play-fighting, which can escalate into real aggression among older fledglings, babblers establish their position in the group hierarchy. Among adults, challenges to a higher-ranking bird often meet with punishment or aggressive displays, and the loser may be injured or even evicted from the group. An evicted bird must find another group to join – without the security of cooperative predator vigilance, a lone babbler’s chances of survival are low. Joining a new group successfully means overcoming the group’s initial hostility. Small groups are kinder to strangers who offer themselves as extra helpers, but joining a group is very costly. It often involves days of aggressive fighting and displays, during which time the prospecting individual can lose a lot of weight. To suppress mating opportunities among their underlings, the top-ranking male and female in each group act aggressively towards other group members of their own sex – that way forcing
Messages from birds subordinates to focus their efforts on helping to raise the dominant pair’s young. So, for a subordinate, the ultimate prize is to inherit the dominant position or to form a new group with itself as the dominant breeder. To this end, groups of brothers or sisters might band together to form single-sex coalitions. A breeder in a small group without helpers of the same gender is vulnerable to such challengers, who quickly detect opportunities to seize control. In the days before attempting a dominance takeover, the single-sex coalition does some serious reconnaissance, visiting surrounding groups to assess group composition before going into action. Pied babblers cooperate for the benefits it brings – increasing the production of young, better vigilance against predators, and effective defence of territory. But cooperation turns into conflict when group members try to reap the greatest possible rewards from group-living at too great a cost to others in the group. The constantly changing cost:benefit ratio of cooperation versus conflict in this dynamic bird society shows how varied are the behavioural strategies in a single population – and how useful it can be to explore such trends if we want to explain, on a broader scale, the evolution of cooperative behaviour.
Saving seabirds at risk South Africa juts out into a dynamic and productive area of ocean that hosts nearly one third of the world’s seabird species, with the Benguela upwelling region being home to seven species found nowhere else5. Seabirds dominate the list of globally threatened species found in South Africa, and the chief danger is accidental death caused by fishing. Albatrosses and petrels are especially at risk because they are long-lived, start breeding only after the age of 10 years, and raise at most just one chick a year. Over the past decade, Peter Ryan and his colleagues have been assessing the impacts of longline and trawl fisheries on seabirds. Longline fishing drags birds under water and drowns them. The birds either swallow baited hooks or get entangled in the line
Top left: Albatross being fitted with a satellite tracker. Samantha Petersen, assisted by Barry Watkins, attaches a tracking device to an albatross to learn more about how these birds interact with fishing vessels. Photograph: Peter Ryan
Top right: Researcher Andrea Angel holds a Tristan albatross (Diomedea dabbenena) on Gough Island in the south Atlantic. The island is owned by the United Kingdom, but is generally inhabited only by South African scientists and the crew of a weather station. South Africa has operated there since 1956. Photograph: Angel/Wanless
Below: Seabirds gather around trawlers in their thousands to pick up discarded fish or bait, or simply to help themselves to part of the catch. Research by the Centre (mainly through the BirdLife and WWF Responsible Fisheries programme) is helping to reduce the numbers of seabirds killed accidentally by the longline and trawl fisheries. Photograph: Samantha Petersen
Physiological pathways to survival Any animal responds to its environment through physiological mechanisms that link the physical and chemical processes in the cells of its tissues to its performance and behaviour. Changing environments affect an animal’s survival and reproduction by means of these basic physiological pathways. Scenarios of future global warming indicate, for instance, that the arid western regions of South Africa, including the Karoo and the Kalahari, could become hotter and drier. Birds and other animals in these environments will encounter higher temperatures, which will also increase the amount of water they need to stay cool. Increased water requirements, together with decreased water availability, will very likely reduce the ability of many animals to survive. Andrew McKechnie has tried to understand the ways in which an animal’s environment influences its physiology as well as the processes by which species adapt to different environments through evolutionary modifications of parts of their physiology. One of his projects looks at the ecology and evolution of controlled hypothermia. Many birds, such as hummingbirds, mousebirds, and nightjars, slow their metabolisms down when they’re inactive,
to offset the energy costs of maintaining a high body temperature. This cools them to well below normal temperature. This phenomenon has been well studied in North America and Australia, but not in Africa. To determine whether local species use similar ways to conserve energy, controlled hypothermia is being examined in various southern African birds. Studies conducted during July 2006 revealed that freckled nightjars (Caprimulgus tristigma) regularly enter torpor during winter nights, on some occasions lowering their body temperature right down to about 12 °C.
5. The seven species occurring nearly exclusively in the Benguela upwelling region are the Cape gannet (Morus capensis), Cape cormorant (Phalacrocorax capensis), bank cormorant (Phalacrocorax neglectus), crowned cormorant (Phalacrocorax coronatus), Hartlaub’s gull (Larus hartlaubii), and the Damara tern (Sterna balaenarum). Endemic subspecies are the kelp gull (Larus dominicanus vetula) and swift tern (Sterna bergii bergii).
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Messages from birds
Top: Dead albatross heads returned by a longlining vessel operating in South African waters. Albatrosses are killed by longlining fishing vessels that do not implement measures to protect the birds. Photograph: Peter Ryan
Above: This video still from a night-time camera shows house mice gathering around a large Tristan albatross (Diomedea dabbenena) chick to begin feeding on wounds they open up on the bird’s body, literally eating it alive. Photograph: Angel/Wanless
Southern giant petrel (Macronectes giganteus) in flight. Photograph: Peter Ryan
Above: A tori or bird-scaring line attached to a trawler helps to keep seabirds away from the trawl cables that can drag them under water. Photograph: Peter Ryan
when the baited hooks are deployed from the vessel. Hundreds of thousands of seabirds are estimated to be killed in this way around the world each year. Samantha Petersen works at designing and implementing measures to protect the birds – such as weighting lines to make sure they sink out of reach of seabirds faster. Efforts such as hers have significantly reduced bycatch in the toothfish and hake fisheries, but vessels
Assessing fishing impacts on seabirds Estimating the numbers of birds killed by fisheries depends largely on independent fishery observers recording bird mortalities. ■ For longline fisheries – calculations are fairly straightforward. Most birds killed are hauled on deck as part of the catch. The number killed can be extrapolated to the entire fishing fleet’s effort from what has been observed, though accuracy depends on the coverage by observers. ■ For collisions with trawl wires – estimates are more difficult, as few of the birds killed are brought on board. Dedicated observers watch or videotape the warps to record the number of collisions and the proportion of birds that fail to surface after being dragged under water. The work is labour-intensive, and only a small fraction of fishing effort can be observed, so estimates of total mortality are crude. In both cases, extrapolations are made more accurate by taking into account other factors affecting the likelihood of birds being caught (such as season, and time of setting or state of the moon for longlines, and whether or not offal is being discharged from trawlers).
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targeting tunas and other large pelagic fish still cause problems. The tuna fisheries’ longlines are designed to drift at a predetermined depth, so they can’t be weighted as heavily as lines targeting fish further down, such as hake and toothfish. So pelagic lines tend to remain close to the surface for longer, making it harder to keep baited hooks away from the seabirds. In the last few years, trawl fisheries have been recognized as causing significant deaths among albatrosses. The birds collide with the trawl cables as the trawl net is being released, then they’re dragged under water and drowned. Extrapolation from the evidence suggests that the hake trawl fishery kills some 400 albatrosses each year in South African waters. Skippers, fishery observers, and compliance officers are helping with testing and implementing measures to avoid this problem – such as dragging devices close to the trawl cable to scare the birds away. These measures also help the trawl fishery to keep its Marine Stewardship Council certification as a fishery that’s harvested in a sustainable way and does not harm the ocean ecosystem. Further conservation dangers come from the predators that people have introduced to islands where seabirds breed. At Gough Island in the central South Atlantic, researchers Ross Wanless and others have found that introduced house mice are killing large numbers of seabird chicks, including those of the endangered Tristan albatross. The mice nibble at wounds they’ve opened up on the chicks and literally eat the birds alive. Even though the albatross chicks are about 200 times bigger than the mice, they don’t defend themselves because they’ve evolved in an environment that had no mammalian predators for millions of years before humans arrived. In normal conditions, at least 70% of albatross pairs would manage to raise a chick each breeding season, but in the areas where the mice now abound, fewer than 10% of Tristan albatross pairs manage to raise one. Biodiversity’s economic value Biodiversity and healthy ecosystems are linked with valuable goods and services to society, but politicians and decision-makers often ignore biodiversity conservation. Perhaps conservationists could communicate better the values of biodiversity in the currency of greatest relevance to politicians – its direct economic value. Jane Turpie’s research, for instance, integrates ecological, social, and economic knowledge to reveal the monetary value of various components of biodiversity and ecosystem function. Her projects evaluate individual ecosystems such as estuaries, national parks, and other protected areas, with a view to developing integrated conservation plans for local and national economies. One case study examined the Mngazana estuary in the Eastern Cape, which has the third largest mangrove forest in South Africa – a particularly endangered habitat type. Marketprice methods used information collected in
Messages from birds household surveys and focus-group discussions, to estimate what the mangroves were worth as a source of building materials, as a nursery ground for the subsistence fishery, in harvesting honey, and in local tourism. Their value to the local community was estimated to be as much as R3.4 million each year! The economic benefits of healthy ecosystems to communities of people are being documented globally. Birds have special value as indicators of the environments that they inhabit and share with us. The survival messages they send out are pointers to their own future and also to ours. ■
Members of the DST–NRF Centre of Excellence at the Percy FitzPatrick Institute who contributed to this feature are the manager, Dr Penn Lloyd, and his colleagues at the Percy FitzPatrick Institute, University of Cape Town: Professor Phil Hockey, Dr Peter Ryan, Professor Graeme Cumming, Colleen Seymour, and Dr Amanda Ridley; also Dr Rauri Bowie (Department of Botany and Zoology, University of Stellenbosch); Dr Andrew McKechnie (School of Animal, Plant and Environmental Sciences, University of the Witwatersrand); and Dr Wayne Delport and Professor Paulette Bloomer (Department of Genetics, University of Pretoria).
Conservation success – the African black oystercatcher The African black oystercatcher (Haematopus moquini) breeds on the coasts and off-shore islands of southern Namibia and South Africa. In the early 1980s, the population worldwide had dropped to fewer than 5 000 birds (including no more than 2 000 breeding pairs) and the species was classified as vulnerable to extinction. By 2005, when reassessed, numbers had risen to almost 6 700 birds – an increase of some 34%*. This resounding conservation success came from public involvement in the Oystercatcher Conservation Programme, launched by Phil Hockey in 1998 to tackle the problem. Oystercatchers lay eggs and raise chicks on beaches and rocky shores at the height of the summer holiday season. The research question was: why were their numbers so low? With a network of more than 300 volunteers, this ‘citizen science’ study of the breeding success of hundreds of pairs of oystercatchers along the South African coast – from Namaqualand to East London – found the answer. The volunteers monitored individual nesting attempts and recorded success rates; they were involved in annual surveys of the numbers of adults and juveniles along more than 1 000 km of coast; they found and ringed chicks, collected empty shells left where adults had been feeding chicks, and searched for ringed birds in roosts. Oystercatchers are long-lived (many breeders are more than 25 years old), so an average pair need rear only one chick to independence every three years to maintain stable adult numbers. On offshore islands, protected by legislation and by their inaccessibility, oystercatchers have surplus chicks, and banding studies showed that island-born chicks hardly ever move to breed on the mainland – they prefer to queue till a breeding vacancy arises. Yet, on the mainland coast, many local populations produced chicks at a far lower rate – alarmingly, chicks were dying within the first two weeks after hatching. Initially, it was suspected that they might have died of starvation, because disturbance reduces the foraging time available to adults, and places more pressure on adults to feed themselves and their offspring. But comparing the body condition of chicks of different ages that survived to fledging with those that died proved this theory wrong. The deaths were clearly instantaneous – apparently caused by drowning, trampling, or predation. The evidence then pointed to dogs as the main culprits. Unleashed by their owners while being walked on public beaches, dogs were allowed to roam. Baby chicks are smelly, so dogs can quickly find them. And because the chicks can’t fly in the first month of their
lives, dogs can easily chase them down and kill them. Since the 1980s, and increasingly in the past decade, many beaches have been closed to dogs altogether – in other cases owners have to walk them on a leash during summer. The danger to oystercatcher chicks immediately diminished. Another benefit to oystercatchers came in 2001, when off-road vehicles (SUVs) were banned from South African beaches. No longer were the SUVs crushing eggs and small chicks. Remote areas could now stay relatively inaccessible to the large numbers of people who’d been disturbing breeding birds and, in this way, reducing breeding densities. The off-road vehicle ban benefits not just the birds but other coastal plants and animals too. Returning remote beaches to pre-vehicle remoteness has helped to save many species of severely over-exploited and threatened fish from the pressures of angling; seabirds have returned to mainland roosting sites unused for many years; and coastal dunes and vegetation have been able to begin the road to recovery. For more on the Biodiversity Conservation Academy, run in conjunction with the DST–NRF Centre for Invasion Biology, University of Stellenbosch, and for details on how to apply for the January 2007 Academy, visit http://www.fitzpatrick.uct. ac.za/docs/nuggets.html * Some sections of coast in the Eastern Cape, Northern Cape, and Namibia were not surveyed for the first global population assessment in the early 1980s. The 2005 assessment combined aerial surveys of remote stretches of coast (such as Namibia’s diamond coast) with ground survey data. Because the ground surveys were incomplete (although covering more than 1 000 km of coast yearly for five years), the new population estimate required partial extrapolation. The coast was divided up by geographical region and by habitat. Comparing counts from identical sections of coast surveyed 25 years apart made it possible to apply a correction factor to sections of coast missing from the most recent surveys, and to apply this correction to the counts made in the early 1980s.
For extensive details about the region’s birds, consult P.A.R. Hockey, W.R.J. Dean, and P.G. Ryan, Roberts Birds of Southern Africa (7th edition) (The Trustees of the John Voelcker Bird Book Fund, Cape Town, 2005). Also recommended is the field guide by I. Sinclair, P.A.R. Hockey, and W. Tarboton, Sasol Birds of Southern Africa (3rd edition) (Struik, 2002) and D. Attenborough, The Life of Birds (David Attenborough Productions, 1998). For more on the research projects at the Percy FitzPatrick Institute, including research papers and more popular articles, visit www.fitzpatrick.uct. ac.za/docs/publist.html. (If you want a copy of any of the journal articles listed on this site, e-mail your request to the Niven Librarian, whose details appear on the website, and you will receive your pdf, or a hard copy, by post.)
Above: A pair of African black oystercatchers (Haematopus moquini) on a mussel bed. This species breeds on South Africa’s coasts. Disturbance by beach users, especially by unleashed dogs, seriously reduced its breeding success. Credit: Jesse Walton Above left: An oystercatcher chick in hiding. Most of the mortalities caused by people and their dogs occur among chicks less than two weeks old. Photograph: Jesse Walton Above: SUVs on beaches crush birds’ eggs and small chicks and damage many different types of coastal plants and animals.
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Careers in S&T Q Messages from birds
Work in conservation biology I
n the early 1970s, the rate of species extinction was thought to be one species per year but current estimates place extinction rates somewhere between 36–78 species a day, about 100–1 000 times higher than they would be without interference by humans*. Out of the urgency of this global ecological crisis came the multidisciplinary science of conservation biology, developed specifically to deal with declining biological diversity.
conservation. Most found work fairly quickly after graduation: 58% were employed in new jobs in their profession within six months. Graduates were spread mainly across four main sectors of work: government and parastatals (26%); business and consultancies (22%); educational institutions (20%); and NGOs (19%). The most commonly held positions were in management (36%) and in scientific research (20%). Of the graduates in the survey, 70% work in Africa (with 54% working in South Africa and 16% elsewhere). ■ – Colleen Seymour
What do conservation biologists do? Conservation biologists act to maintain Earth’s biological diversity. Their two main goals are (1) to understand the effects of human activities on species, communities, and ecosystems, and (2) to develop and implement practical ways to prevent biodiversity loss. Trained in an array of skills, individual conservation biologists often gravitate towards activities that appeal to them most. ■ With logic and computer programming skills, for example, you could combine modelling with data collection from fieldwork to anticipate how increased mortality, habitat loss, or reduced breeding success will affect a species. Modelling current mortality rates of the African penguin (Spheniscus demersus) – with oil spills from large ships the main cause of death – indicates, for instance, that, at present rates, the species will go extinct within 50 years. ■ If you enjoy laboratory work, you could specialize in conservation genetics and help to identify new species or analyse evidence in criminal investigations (for instance, to detect the origins of poached abalone). ■ Working with Geographic Information Systems would enable you to prioritize habitats or regions of conservation concern, which, in turn, helps to guide conservation strategies. ■ Work in resource economics means finding ways to attach monetary value to environmental goods and services not normally considered in financial terms, such as pollination and seed dispersal. Many conservation biologists publish their research in academic research journals and present their work and exchange ideas at conferences**.
How can you qualify? Conservation biologists are hired at various levels, and qualifications include a national diploma or a B.Tech. from a technikon or university of technology, or a degree in the life sciences. The Percy FitzPatrick Institute, for instance, offers a 14-month M.Sc. degree in Conservation Biology to students from both academic and professional backgrounds.
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Above left: Conservation Biology students make regular field trips to gain hands-on experience of conservation science. Here, for a long-term study of the dynamics of a marked population of proteas, a student measures the height of a young plant. Photograph: Peter Ryan
Who will employ you? Possible employers include: the Department of Environment and Development Planning, the South African National Biodiversity Institute, the Council for Scientific and Industrial Research, South African National Parks, private consultancies (where conservation biologists might work on environmental impact assessments), educational institutions, and environmental non-governmental organizations such as the World Wildlife Fund (WWF), the Endangered Wildlife Trust (EWT), Wildlife and Environment Society of South Africa (WESSA), BirdLife South Africa, and the Botanical Society. In a recent survey tracking the progress of graduates of the Conservation Biology programme at the Percy FitzPatrick Institute, as many as 89% of the 81 respondents worked in
Left: Tshifhiwa Mandiwana comes from South Africa’s Limpopo province. She completed her B.A. and education diploma at the University of Venda; worked for three years as a highschool biology teacher; returned to university to complete a B.Sc.(Hons) in the biological sciences, then completed her master’s degree in Systematics and Biodiversity Science at UCT. After working as a researcher at the Northern Flagship Institute (Transvaal Museum) while studying part time towards a doctorate, she took up her current lecturing position in the Botany Department at UCT. She is investigating the systematics of African francolins and spurfowls and the population ecology of the greywing francolin. Her research involves sequencing the DNA of the various species to understand their evolutionary relationships and the rates of dispersal of individuals among populations of greywing francolin – important work for the commercial hunting industry in the Eastern Cape. Photograph: Robert Massman
For details about the M.Sc. in Conservation Biology, visit http://www.fitzpatrick.uct.ac.za/docs/ consover.html. To find out about other courses in biology and conservation at undergraduate and postgraduate levels, visit the websites of South Africa’s higher education institutions.
It was Norman Myers, at Oxford’s Green College, who recalculated the original estimate. He upped it to roughly 50 species a day after including the rapid decline in tropical forests. ** The annual international conference for conservation biologists in 2007 will be held right here in South Africa, at the Nelson Mandela Metropolitan University.
Q News Andromeda’s rings of fire1 Violent collisions often demarcate the appearance of galaxies in our early Universe. Photons of light, travelling for over 10 billion years, frequently reveal myriads of galaxies with a tempestuous past: colliding galaxies in the formative stages of our Universe often seem the norm rather than the exception. Our own Galaxy, the Milky Way, with its hundred thousand million stars, appears as rivers, with dark lanes or rifts that seem almost to split the band of the galaxy lengthwise in two. These dark rifts are vast clouds of dust, absorbing background starlight so dramatically that all we see is apparent emptiness. The effect is much the same as thick fog obscuring a traffic light. The dust grains are tiny – with typical diameters less than a millionth of one metre (the equivalent of a thousandth of 1 mm). Enter the world’s grandest infrared observer of these effects in space, the Spitzer Space Telescope, launched in 2003. It actually shows astronomers the radiation emitted from tiny molecules and minute grains of dust. Masks of cosmic dust clouds are unveiled, often revealing intricate structure and detail. The eyes of Spitzer were turned towards our closest spiral galaxy, the majestic Andromeda Spiral located about 2.5 million light years from us in the 30-strong ‘Local Group of Galaxies’ to which our Milky Way Galaxy belongs. The Local Group spans about 10 million light years across, and Andromeda, its largest spiral galaxy, has an estimated diameter of 140 000 light years. Images secured with the orbiting Spitzer Telescope revealed two glowing rings of fire. The outer ring has a diameter of approximately 65 000 light years. The inner ring, whose dimensions are some 4 900 light years by 3 300 light years, had never before been discovered because it was completely hidden, in optical light,
Glowing rings of fire observed in the Andromeda Spiral Galaxy. The newly discovered inner ring has the signature of a violent collision, as the companion galaxy M32 plunged almost ‘head-on’ near the centre of the disk of Andromeda. The Spitzer Space Telescope was pointed in 700 different directions to secure this image, which contains 3 000 individual data frames. Image: Courtesy of Nature by the luminous stars in the central bulge of Andromeda. What event could have caused this remarkable set of rings, whose centres do not coincide with the centre of the galaxy? The penny dropped. A collision of Andromeda with one of its companion galaxies, Messier 32! Think of a simple analogy – that of tossing a stone into a pond of water. Rings or ripples are created, travelling outward with time. The French members of the investigating team simulated the history of the Andromeda Spiral using sophisticated computer codes, and they concluded that Messier 32 had indeed collided almost head-on with Andromeda to create the remarkable off-centred rings observed by Spitzer. Messier 32 had impacted the disk at over 250 kilometres per second (km/s), creating two rings of fire, whose outward expansion velocities are about 50 km/s and 18 km/s, respectively. In cosmological terms, the time of collision is remarkably recent: only 200 million years ago. On Earth, the continents had not yet separated and dinosaurs roamed freely. It was an astronomical task – in the truest sense of the word – to capture the details of
Andromeda with the Infrared Array Camera (IRAC) on board the Spitzer telescope, for the galaxy covers a huge angular area in the sky. The field of view with IRAC is relatively small, so the telescope was moved in 700 different directions to cover the entire galaxy. The total exposure time of the individual frames that make up the discovery image published in Nature was not 1 or 2 seconds, but over 50 hours! One of the world’s foremost experts on galaxies, Kenneth Freeman, called this discovery “one of the most important yet made concerning that galaxy’s history, ever since Charles Messier catalogued it as a diffuse object on August 3, 1764.” – A shortened version of the story as told by David Block, Director: Anglo American Cosmic Dust Laboratory, University of the Witwatersrand (www.davidblock.com) 1. This discovery was announced in Nature (19 October 2006), in the article “An almost head-on collision as the origin of two offcentre rings in the Andromeda galaxy”, by a team of astronomers from South Africa, France, and the United States: David Block and Robert Groess (University of the Witwatersrand, South Africa), Frederic Bournaud and Françoise Combes (Observatoire de Paris, France), and, from the Harvard-Smithsonian Center for Astrophysics in the USA, Pauline Barmby, Matt Ashby, Giovanni Fazio, Mike Pahre, and Steve Willner.
The oldest fossil lamprey in the world2 Jawless fish are the oldest fish known in the fossil record, and they persist today in the form of lampreys and hagfish. As one kind of the only living jawless fishes, lampreys have long been the focus of scientific attention. Living lampreys are known from all continents except Africa. Their appearance and blood-sucking lifestyle make them the only living creatures definitely descended from a vertebrate ancestor that had not yet acquired jaws. Despite being representatives of a very ancient fossil lineage, lampreys are highly specialized for a parasitic existence, as they feed by sucking from living fish, using a suction disc and aided by a rasping tongue. The evolutionary history of lampreys is mostly unknown, their boneless cartilagenous skeleton having left virtually no fossil record. Only three fossil species were previously described, in none of which the sucking apparatus is apparent. A new paper reports the discovery by Robert Gess of a remarkably wellpreserved fossil lamprey from the 360-million-year-old Witteberg Group of rocks near Grahamstown. Only 42 mm long, the little fossil fish is 35 million years older than any previously discovered fossil lamprey. It reveals details of its fin, gill basket, and, most important, the circular jawless mouth, which, clearly situated at the centre of a large sucker disc and encircled by small teeth, is remarkably like that of living lampreys. The fossil has been named Priscomyzon riniensis. The genus name is from Latin prisco (ancient) and myzon (a lamprey), and the species name is from Rini (the Xhosa name for Grahamstown and the surrounding valley). The sucker disc and circumoral teeth in this specimen reveal that the lamprey adaptations for a blood-sucking lifestyle were acquired in ancient seas, before the coming of modern fish faunas. It shows that lampreys are in fact ‘living fossils’, which have remained largely unaltered for more than
Comparison of a reconstruction of Priscomyzon riniensis, illustrating tadpole-like body proportions and large oral disc (a) and a modern lamprey Lampetra fluviatilis (b). The horizontal bars indicate the span of the oral disc in each species. 360 million years and have been specialized for a parasitic way of life for a very long time. Exceptional survivors, they pre-date the advent of modern fish faunas and have survived four major extinction events. This fossil is one of a remarkably diverse fossil fish and invertebrate fauna, revealed by Gess over more than a decade of painstaking excavations in a roadside quarry near Grahamstown3. 2. This discovery was announced in Nature (26 October 2006), in the article “A lamprey from the Devonian period of South Africa”, by a team from South Africa and the United States: Robert Gess and Bruce Rubidge (Bernard Price Institute[Palaeontology], School of Geosciences, University of the Witwatersrand) and Michael Coates (Department of Organismal Biology, University of Chicago). 3. The excavations were made possible with the assistance of the National Roads Agency, which allowed the site, including the material that contained Priscomyzon, to be rescued.
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The birth of a black hole Martin Still explains where black holes come from – and what the Southern African Large Telescope is doing as a front-runner in the burgeoning field of gamma-ray-burst chasing.
Top: Once per day on average, the Earth’s atmosphere is briefly illuminated by the intense glow of a black hole being born. These incredibly violent and energetic events created copious gammarays (-rays) that have travelled for a large fraction of the age of the Universe to reach us. Picture: Courtesy of NASA
Above: The initial flash observed from a gamma-ray burst is most commonly caused by the collapse of a massive star as it runs out of nuclear fuel. As hydrogen is depleted in the stellar core, external pressure increases enabling the star to feed off increasingly heavier elements such as helium (He), carbon (C), and oxygen (O). This very process creates the heavy atomic structures that sustain life in the Universe – but it’s not a stable process. The star’s outer layers will inevitably come crashing down onto the dense core, releasing enough energy briefly to outshine entire galaxies. Picture: Courtesy of NASA
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very day, orbiting satellites record light from the most intense explosions since the Big Bang. What are these awesome, violent events that happened so soon after the Universe was born? They’re called gamma-ray (-ray) bursts and everything about them is extreme. They’re bright, incredibly short flashes (sometimes lasting just a few thousandths of a second!) from random points in the sky, with emissions peaking at enormously high energies1 in the hard X-ray region of the electromagnetic spectrum. Finding a burst isn’t easy, as it’s invisible to the human eye and to detectors on the ground (that’s because the Earth’s atmosphere is too opaque to let such high-energy photons2 through). But satellites with the right equipment can pick them up and, during the 1990s, an average of one burst per day was recorded by NASA’s Compton Gamma Ray Observatory3. This showed that gamma-ray bursts were a common phenomenon and that they had 1. Gamma-ray emissions peak at very high energies – 100 kiloelectronvolts (keV); 1 hard X-ray photon contains the same energy as about 100 000 optical photons. 2. A photon is a particle of electromagnetic radiation. It has zero rest mass, zero charge, and travels at the speed of light. The energy of a photon is related to its frequency. A gamma-ray photon, for instance, has far higher energy than a photon at a radio frequency. 3. The Compton Gamma-Ray Observatory (GRO) is a NASA satellite for observing gamma-rays from celestial objects. Named after US physicist Arthur Holly Compton (1892–1962), it was launched in 1991 and operated until 2000.
remarkably homogeneous properties. Distances to the sources of gamma-ray bursts are almost unimaginably great. Some occur at the very edges of the observable Universe. Given that the speed of light is finite at 300 000 kilometres per second, the time it has taken for the light that travels from these events to reach us is often 90% or more of the age of the Universe. Because the bursts are so bright, the luminosities of these events must be enormous – for a few brief seconds they outshine entire galaxies. What can be the cause? There’s only one phenomenon we know of, other than the Big Bang itself, which produces such incredible energy over such a brief space of time – and that’s the birth of a black hole.
core into a tiny volume, forming a black hole. Much of the stellar material in the outer layers is lost to space in the process, with a massive release of energy accelerating the detritus at a velocity close to the speed of light. Such an event is often brighter than the rest of the entire observable Universe, albeit very briefly. If you happen to be looking in the right direction, at the right time, with a high-energy detector, you can observe the flash of a black hole being born. First discoveries Most urban myths are false, but the one about gamma-ray bursts being discovered by the US military happens to be partially true. At the height of the Cold War, in the late 1960s, the United States flew a fleet of orbiting gamma-raysensitive satellites, pointed down at the Soviet Bloc to monitor the moratorium on atomicbomb testing in the Earth’s atmosphere. For security reasons, the Defense Department sat on the result for several years, but ultimately it became apparent that frequent gamma-ray flashes occurred from locations not towards the Earth but from far out in space. The technology of that era could at best provide high-energy detectors that acted as ‘light buckets’ with limited directional information. Without more precise locations, there was no way to follow ▲ ▲
Black hole origins What are black holes and how do they form? It’s not possible to observe a black hole directly, but we know about them from the way in which their powerful gravitational fields attract and trap matter that falls towards them from companion stars or other sources. Here’s how we think the process works. Everything in the Universe that has mass also has a gravitational field; the strength of the field increases as you approach the object. To escape the pull of a gravitational field, you have to exceed a certain speed or velocity; the closer you are to the object, the more velocity you need to be able to escape. The speed of light is the highest velocity that an object can obtain – it is great, but it’s ultimately finite. Unlike the speed of light, however, the strength of an object’s gravitational field has no limits. When the strength of the field is so great that its escape velocity exceeds that of light, then nothing, not even photons, can escape its influence. And when this situation occurs, the central object is considered to be a black hole. It’s not mass but density that’s the critically important property of a black hole. In fact, black holes are thought to exist with masses ranging from that of the Moon to a billion times the mass of the Sun4. The mechanisms that create black holes are often poorly understood, but we believe that these objects exist because of what theoretical calculations and observations have revealed so far. Some detailed formation scenarios have been constructed for a subpopulation of black holes with masses of 3 to 30 times the mass of the Sun4. One scenario involves the collapse of a star. In essence – to over-simplify, for convenience, the complexities of stellar structure and particle physics – a star contains low-mass atomic particles that are converted into heavier atoms and energy. It’s that energy, propagating outwards, which keeps the star from shrinking rapidly. Eventually, when a star runs out of lowmass atomic particles, it runs out of fuel and its outer layers start to collapse. The pressure of its collapsing outer layers depends on the initial mass of the star. The collapse of one of the most massive stars contains enough force to squeeze the stellar
Above: The Swift mission is unorthodox in that it is dedicated to the observations of a single type of astrophysical phenomenon (gammaray bursts) and it carries instruments covering a wide range of wavelengths. Other missions are generally greater in scientific scope but narrower in function. In addition, Swift can run autonomously, detecting bursts and pointing its suite of instruments to them within a minute, an order of magnitude faster than most other satellites. When you’re investigating gamma-ray bursts, every second is vital. Picture: Courtesy of NASA
4. The mass of the Sun is calculated to be 1.989 × 1030 kg.
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too slow to catch the afterglows, but the few that were detected through imagers and spectrographs indicated that bursts had cosmological origins at extragalactic distances, and a few could even be identified with known host galaxies. The scientific community in 1997 was thrilled by these discoveries. Astronomers quickly realized that the nature and distance of gamma-ray bursts gave them great potential to probe the formation and death of stars, and the structure and evolution of the Universe. Plans were made to construct and fly orbiting observatories dedicated to locating and monitoring gamma-ray bursts accurately. In the past half-dozen years, two missions (called HETE-2 and Swift6) have been launched and are producing incredibly detailed data, both from their own instruments and by rapidly relaying target coordinates to observatories around the world through a dedicated communication network. Above: The Southern African Large Telescope (SALT) near Sutherland in the Karoo desert of the Northern Cape. Using an internet link to NASA’s Goddard Space Flight Center, it is performing a programme of rapid-response gamma-ray-burst chasing in collaboration with SALT’s US partners, the University of North Carolina and Rutgers University. Photograph: Courtesy of SAAO
Right: On Earth, we are shielded by our atmosphere from the dangerous high-energy particles from a gammaray burst. The down side is that, to observe these events as they occur and alert optical observatories around the world, we must launch spacecraft above the absorbing layers of our atmosphere. Swift is an orbiting satellite dedicated to the detection of gamma-ray bursts, and was launched aboard a Delta rocket on 20 November 2004 by NASA, in partnership with US, UK, and Italian institutions.
5. The BeppoSAX X-ray astronomy mission was named after the Italian astronomer Giuseppe ‘Beppo’ Occhialini (1907–1993) and launched in April 1996; SAX is the acronym for ‘Satellite per Astronomia a raggi X’. The satellite has instruments for broadband timing and spectroscopy. 6. HETE-2 (the abbreviation for HighEnergy Transient Explorer-2) is a joint US–French–Japanese satellite launched in October 2000 to detect gamma-ray bursts. Its three instruments search for bursts, find their location, and alert observers on Earth. The NASA satellite Swift was launched a couple of years later in 2004 to detect and monitor gamma-ray bursts. It can determine the distance to some gamma-ray bursts and study the afterglow to help to clarify the physical processes involved.
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Photograph: Courtesy of NASA
up these detections, so for several decades the result remained a conundrum. As more bursts were detected it could be shown that they never repeated and did not come from any preferred direction in the sky. The breakthrough came following technological advances. The high-energy detectors on board the Dutch–Italian BeppoSAX satellite5 boasted enough image resolution to be able to direct its own instrumentation – as well as other observatories in space and on the ground – to the approximate location of a burst. It was found that, after these explosions, came a longer-lived afterglow across the entire electromagnetic spectrum. The afterglow is what results when the jetsam of the explosion rams into the cold and inert interstellar gas and dust surrounding the new black hole. Because this afterglow is typically very faint and fades within a day, the trick is to point instruments to it as rapidly as possible. Responses were often
SALT and gamma-ray bursts The Southern African Large Telescope (SALT) is all set to make a unique contribution to gammaray burst science. What features give it the edge? First, there’s the size of the telescope. It has the largest mirror array of any single telescope in the southern hemisphere. Since afterglows are intrinsically faint, SALT’s massive collecting area allows it to detect sources faster than other southern observatories and monitor them for longer as they continue to fade. Second, SALT’s geographic location is astronomically isolated. With oceans both east and west, there are afterglows that only SALT – among the world’s large telescopes – can slew to rapidly. Third, there’s SALT’s ability to respond rapidly to the bursts. The Swift satellite, which detects most of the events, reports the positions of bursts to the Mission Operations Centre at Penn State University, USA, within a few minutes. Sky coordinates and burst properties are delivered to SALT astronomers automatically via e-mail and arrive within five minutes of the onset of the burst. The scheduling of SALT is very flexible. A gamma-ray burst is given a high priority and immediately interrupts most existing observing programmes, so the telescope can potentially be observing the afterglow within ten minutes. The other flexible feature of SALT is its ability to swap instrumentation quickly. Depending on the properties of the burst and scientific goals, SALT can perform on-the-fly astrometry, multicolour imaging, high-speed photometry, spectroscopy, polarimetry, or a combination of these observations. This is a unique capability for any 10-m class telescope. Finally, a planned addition for 2008 is an infrared arm for the spectrograph, which will allow instantaneous and unprecedented optical and infrared spectroscopy of the afterglow. The infrared detector is vital for observing those sources that lie behind the ‘arms’ of our own galaxy, rich in obscuring dust, and also for detecting the most distant bursts where the expansion of the Universe has redshifted7 all the ultraviolet and optical light to infrared wavelengths.
Prospects The field of gamma-ray-burst chasing is still in its infancy. The launch of satellite observatories dedicated to the chase has opened the way for ground-based facilities to further our understanding of the large-scale evolution of the Universe, the earliest star formation, and the birth of black holes. SALT has now proved its worth in this endeavour and with more and more of its unique capabilities coming online we eagerly anticipate more great results in the future from our African observatory. ■ Dr Still is currently a staff astronomer at the Southern African Astronomical Observatory. He was previously contracted to NASA as part of the team that built, launched, and operates the Swift gamma-ray-burst satellite.
Above: Cartoon illustrating the ability of an observer to examine a gamma-ray burst (the source of light). At the top, the wavy line indicates the light moving through deep space and many thousands of galaxies (in this case, four are indicated) in the line of sight between the light source (right) and the observer (left). Each galaxy absorbs some of the light from the source, as indicated by the ‘spectral line’ beneath, in which the dips represent the light absorption by each of the (four) galaxies and the peak on the right represents the very bright source of light. The light is emitted by elements such as hydrogen, iron, carbon, and others as they undergo nuclear burning. Each element has a characteristic ‘signature’ corresponding to a particular combination of wavelengths, which enables us to identify each of the elements present (see diagram on p. 12). The dips, corresponding to changes in the Ly intensity (flux) of the light received, are seen at different wavelengths (from Ly forest the blue end of the electromagnetic z = 3.7 spectrum at the left of the x-axis to the red end on the right), representing Ly edge increasing redshifts7 and hence different distances of the galaxies from the observer. Picture: E. Wright 200
Our first afterglow On 5 June 2006, SALT detected its first gamma-rayburst afterglow, which was given the workmanlike name GRB 060605. The burst triggered Swift during daylight hours SAST (South African Standard Time), so SALT could only slew to the source six hours after the event, when the afterglow had faded to 19th magnitude. Nevertheless, three separate exposures with the Robert Stobie Spectrograph (built by SALT partner, the University of Wisconsin), totalling 40 minutes, revealed breathtaking detail in the afterglow’s spectrum. The snapshot of this source shows incredibly energetic gas cooling around the new black hole. All of the broad and narrow dips in the spectrum (see figure) are caused by the absorption of light from the afterglow by cold hydrogen gas situated across the Universe in the line of sight between the Earth and the burst. Each dip represents an individual galaxy at a specific point in the Universe and at a specific point in history. Not only does this spectrum reveal the vast distance to the source, but it maps the structure and evolution of galaxies across a large fraction of the Universe. At a mind-boggling distance of 12 billion light years, the furthest galaxy in the spectrum is the one that hosts the gamma-ray burst. So, locked within this single spectrum, is a history of galaxy evolution from 12 billion years ago until the present day. The actual distance depends on which model you believe for the content of the Universe but, adopting the most popular, the distance to the burst is 1 000 000 000 000 000 000 000 000 km. To put this event into some perspective, the light from this gamma-ray burst had been travelling for 12 billion years before it reached us. That means the black hole was actually born 12 billion years ago – only 1.7 billion years after the Big Bang! The immediate observation we can make is that, even at this very early time in the history of the Universe, galaxies had formed and the conditions were right for star-birth (and death). The heavier atomic elements produced during the death of massive stars – the very seeds vital for the development of life in the Universe – were already being created and spread at this epoch.
Right: This figure (called a ‘spectrum’) plots the researchers’ view of the 5 June 2006 gamma-ray burst, where 3000 Å is blue light and 6000 Å is red. 4000 5000 6000 The absorption features revealed in Wavelength (Å) the spectrum are all due to absorption by cold material in the line-of-sight between the Earth (left) and the burst (right). The most prominent component of the cold gas is neutral hydrogen within the host galaxy in which the burst occurs. These features provide a measure of the distance to the source via their redshift7. What causes the redshift? The Universe has been expanding ever since the Big Bang. Rather than expand from a single point in space, the expansion is uniform in all directions, hence the further the object, the faster it recedes from us. The Lyman edge is a prominent feature of the hydrogen spectrum of a star, which, if a source is at rest relative to the observer, occurs in the ultraviolet region at 912 Å. At wavelengths shorter than the edge, light is absorbed by neutral hydrogen; the denser the gas, the stronger the absorption. In our spectrum of GRB 060605, we find the Lyman limit at 4300 Å, indicating a redshift (z) of 3.7. The other prominent feature in the spectrum is the Lyman line at 5750 Å. It results from electrons bound to hydrogen atoms jumping from one state to another, allowing the absorption of a photon. This feature is very broad, indicating that the black hole was born in a dense hydrogen region. If you inspect the spectrum between the Lyman edge and the Lyman line, you find Lyman absorption over a broad range of wavelengths; this is known as the Lyman forest. What are we observing here? Remarkably, all these features are Lyman , but they are all due to different galaxies lying between the Earth and the burst. Because they are at different distances from us, their redshifts are different and hence their Lyman features occur at different wavelengths (see cartoon above). Collectively they reveal the structure of the cold Universe in space and time. For more, visit the star formation page at NASA Origins http://origins.stsci.edu/under/stars.shtml; Ted Bunn’s black hole FAQ at http://cosmology.berkeley.edu/Education/BHfaq.html; Ned Wright’s cosmology tutorial at http://www.astro.ucla.edu/~wright/cosmology_faq; the Swift public outreach website http://swift. sonoma.edu; NASA’s Swift mission page http://www.nasa.gov/mission_pages/swift/main/index.html; and the SALT homepage http://www.salt.ac.za.
7. Redshift (symbol z) is the measure of the amount by which the wavelength of light is lengthened (that is, moved toward the red end of the electromagnetic spectrum) by, for example, the expansion of the Universe – a kind of Doppler effect. The American astronomer, Edwin Powell Hubble (1889–1953), was the first person to note the Universe’s expansion from the redshift in light from distant galaxies, and redshift remains the main indicator for estimating the distances of galaxies and quasars.
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The Youth version of South Africa’s State of Environment Report published this year was produced ‘by young people for young people’, involving them directly in creating the kind of world that they will want to inherit and enjoy. Top left: Barley fields in the Overberg. Photograph: South African Tourism
Top middle: A highway in Port Elizabeth. Photograph: South African Tourism
Top right: A farmer tending cattle. Photograph: South African Tourism
Main picture (above): A panoramic view of Johannesburg. Close to 58% of South Africa’s population is urbanized, and rapid urban growth has put significant pressure on the natural environment and its resources. Photograph: South African Tourism
he 2005 State of the Environment Report1 informs young people about the present state of South Africa’s environment and suggests many practical everyday ways to make a difference for the better. The point clearly made in the foreword by the Deputy Minister of Environmental Affairs and Tourism, Rejoice Mabudafhasi, is that: “youth have a special interest in a healthy environment because they will be the ones to inherit it.” The first chapter covers sustainability in South Africa and what affects the environment; the second chapter gives information on the state of the country’s environment; and the final chapter concentrates on human vulnerability. Young people are agents, beneficiaries, as well as victims of whatever changes human activities bring. Involving the youth in preparing this important report, therefore, makes them central to the kind of action that will make the world a better place. The key issue is the recognition, in the words of Wangari Maathai (winner of the 2004 Nobel Peace Prize), that “when the environment is destroyed, plundered, or mismanaged, we undermine our quality of life and that of future generations.” Across the world, however, human consumption is greater than the planet’s ability to sustain it. The ‘Ecological Footprint’ is used as an international measure.
South Africa’s Ecological Footprint is 2.8 global hectares per person, which means that the biological productivity of an area of 2.8 average global hectares is needed to provide for each average individual’s consumption of food, energy, and material, and for the absorption of his or her waste. By comparison, the world average is 2.2 global hectares per person and the average for Africa is 1.2 hectares per person. Symbolic of everything that the environment represents are life-sustaining water, earth, and air. Water makes the earth fertile; earth provides the food we eat; the air we breathe is the basis of our existence. Keeping water, earth, and air healthy and maintaining adequate supplies assures our future, but 21st-century living poses numerous threats. Water Polluted water makes everybody vulnerable, especially young people, says the report. Children without access to safe water or adequate sanitation (especially those who are HIV positive) suffer from ailments such as diarrhoea. Contaminated water transmits hepatitis and cholera, and typhoid is often associated with the absence of clean water and with poor sanitation. South Africa is a water-stressed country. Its average rainfall is some 450 mm a year, about half of the world average of 860 mm a year. Yet water is needed not only for people’s health but also to drive many aspects of the economy. National policy therefore emphasizes
1. The 2005 State of the Environment Report (1996) is a joint publication of the Department of Environmental Affairs and Tourism (Private Bag X447, Pretoria 0001) and the National Youth Commission (Private Bag X938, Pretoria 0001).
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the need to manage the country’s resources in a way that ensures access to safe water for everyone and that, at the same time, makes certain that the ecosystems supplying the water are not damaged or undermined. Earth Land is valuable, explains the report. We build our homes on it, it feeds us, it sustains animal and plant life, and it stores our water. Of South Africa’s approximately 122 million hectares, more than 80% is used for agriculture, but much of that is susceptible to degradation: only about 11% is arable, and 69% is given over to grazing because it is unsuitable for more intensive use. Yet some 43% of South Africans live in rural areas and depend on natural resources for their living, and – despite better agricultural yields from the use of new technologies – the country as a whole is importing a greater proportion of its food.
growth of informal settlements, whose inadequate services expose those who live there to disease, and whose locations are often unsafe – too close to waste disposal sites or heavy industry for safety, or vulnerable to flooding and mudslides.
Air Air quality depends on the quantities of emissions that enter the atmosphere, either naturally or through human activity, and on the ability of the atmosphere to remove pollutants. Indoors, air pollution is common from residential fuel burning, where smoke in confined spaces brings health risks from concentrations of toxic and carcinogenic pollutants. Contamination of outdoor (or ambient) air is rife in areas close to industry and mining. Most carbon dioxide emissions come from burning coal to generate electricity, says the report, followed by industrial processes. “[W]hen the environment is destroyed, Busy traffic is a further concern. The plundered, or mismanaged, we undermine our number of vehicles on our roads – cars, quality of life and that of future generations” trucks, motorcycles, buses, and taxis – has risen by 14% in the past six years The challenge for the nation and the region is to and road-users contribute more than half of the use land in a way that makes it able to feed, house, transport sector’s emissions of greenhouse gases. and support a growing population and economy, Sustainable development at the same time protecting the natural heritage on Sustainable development means achieving economic which they rely. growth to meet the needs of a country’s people and, But access to land and resources remains at the same time, ensuring that the environment on inadequate and inequitable. Between a quarter and which they rely is neither damaged nor destroyed. a third of households are unable to purchase food to Balancing these two essential ingredients for meet the dietary needs of their children, particularly long-term human survival can be a problem. The in poor rural areas. Rapid urbanization as people young people are a crucial part of the solution. ■ migrate to cities in search of work adds to the
Top left: This fire demolished 300 shacks in Khayelitsha, outside Cape Town. Photograph: Trace Images/Lulama Zenzile
Top right: Dead fish in a polluted river. Photograph: IMAGES24.co.za/Beeld/ Daryl Hammond
Above left: Vehicle emissions in South Africa are expected to increase by up to 44% by 2011. Photograph: IMAGES24.co.za/Die Son/ Nerissa Korb
Above middle: An industrial accident pollutes the air. Photograph: IMAGES24.co.za/Vaalweekblad/ Sarie van den Berg
Above right: A forest waterfall in Mpumalanga. The upper reaches of rivers are generally more pristine than lower down. Photograph: South African Tourism
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Where are the fishes? Declining fish populations around the world are making conservationists anxious. Where are the fishes? Which are under threat? What should we do about it? How can the public help? Here are some answers from members of the South African Institute for Aquatic Biodiversity. New dawn for SAIAB In 1996, the world-renowned J.L.B. Smith Institute of Ichthyology, then a Declared Cultural Institution, celebrated 50 years of South African research excellence on fishes. Ten years later, it has re-invented itself as a national research facility of the National Research Foundation (NRF). Under its new name – the South African Institute for Aquatic Biodiversity (SAIAB) – and led by its director, Professor Paul Skelton, it now has national status within the National System of Innovation (NSI), and its collection has been reconstituted as the National Fish Collection. Broadening its mandate has given SAIAB a wider strategic role, and its core function, research, is shifting from exclusively fishes to aquatic biodiversity, to ‘serve Africa’s needs in understanding fishes and aquatic environments’. The next five years will accelerate this process by including genetics, bio-banking, image banking, and geographic information systems, and through disseminating information about aquatic biodiversity. Its education outreach programme and the communication of its scientific output to the
public through popular science articles, presentations, workshops, excursions, lectures, and publications provides an avenue for explaining and exploring the broader aquatic environment. SAIAB has been selected to house the South African Environmental Observation Network (SAEON) Elwandle Coastal Node, another NRF initiative. In this way, the Institute will assume a key role in monitoring the nation’s aquatic biodiversity in the entire South African coastal environment. These and other developments affirm SAIAB’s growing status in the global aquatic environmental network. – Paul Skelton and Penny Haworth Paul Skelton is the Director of SAIAB. Communications Manager Penny Haworth coordinates and develops the Institute’s science communication and education outreach nationally, following the top priority of the NRF’s agency for science and technology advancement (SAASTA) “to grow the pool of learners today who will become the scientists and innovators of tomorrow”.
Coelacanth hide & seek James Richard Stapley
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lines drawn on maps, and processes taking place outside territorial waters affect not just coelacanths but also all marine life, and even people living far inland. The extensive ACEP network of nation partners in the western Indian Ocean – including Mozambique, Tanzania, Kenya, the Comoros, and Madagascar – allows them to explore the region jointly, and each is now known to harbour coelacanths (see Fact File opposite). Discovering the comfort zones Two factors dominate the special places that coelacanths call home. The first, and perhaps most important, is that these nocturnal fishes appear to prefer resting inside caves or under overhangs during the day, coming out at night to forage for food. To find them, we
Scientific painting of a coelacanth (Latimeria chalumnae). The pattern of white markings on the side is unique to each fish and is used to identify individuals. Image: Courtesy of SAIAB. Artwork by Elaine Heemstra (featured in Coastal Fishes of Southern Africa by Phil and Elaine Heemstra)
need to know where underwater caves are. Understanding the seabed geology and terrain helps scientists to predict where caves might be found, but visual confirmation is needed. The other factor seems to be temperature. Coelacanths are rarely found in waters cooler than 14 °C or warmer than 20 °C. These preferences help us to work out where likely coelacanth habitats are likely to be. But coelacanths haven’t read our academic papers and don’t always seem to behave logically! In the Comoros, ▲ ▲
mong South Africa’s enduring science stories is our association with the coelacanth. J.L.B. Smith’s exploits with the first specimen, caught off the coast near East London in 1938 and brought to his attention by Marjorie Courtenay-Latimer, and his breakneck dash to the Comoros Islands to recover the second specimen in a rickety Dakota aeroplane in 1952, were just the start. The dramatic discovery by a group of recreational divers of a coelacanth colony living off our shores at Sodwana Bay in late 2000 opened the next chapter of research and discovery. This long history makes it fitting for South Africa to host the African Coelacanth Ecosystem Programme (ACEP), based at SAIAB in Grahamstown. The ocean pays no heed to national
Q Fact file
The most recent coelacanth fossils known are some 80 million years old, with fossil coelacanths first described by Louis Agassiz in 1839. No later fossils or living coelacanths were seen by western scientists, so the group was considered extinct.
Discoveries ■ 21 December 1938: Captain Hendrik Goosen’s trawler, the Nerine, caught the first coelacanth specimen off the coast of the Chalumna River mouth, west of East London. He left the strange fish at the harbour for Marjorie Courtenay-Latimer, curator of the East London Museum. Describing it as a “pale mauvy blue fish with iridescent silver markings” – the most beautiful she had ever seen – she wrote asking J.L.B. Smith (who taught chemistry at Rhodes University) for an identification. He was holidaying in Knysna at the time, so it took a while before the fish was recognized as a coelacanth. He called it Latimeria chalumnae. ■ 24 December 1952: In the Comoros, the second coelacanth was found. ■ 1987: Live coelacanths were first filmed in the Comoros from Hans Fricke’s submersible Geo. He and his team later filmed many more off the coast of Grand Comoro Island. Geo could not dive deep enough to study coelacanths effectively in the Comoros so, in 1989, a larger submersible, Jago, was built, able to reach a depth of 400 m. ■ 11 August 1991: The first (and so far the only) coelacanth off the coast of Mozambique was trawled near Pebane. It was a pregnant female with 26 near-term pups. ■ 5 August 1995: The first authenticated coelacanth from Madagascar was caught in a deep-set shark gill-net off the coast of Anakaó. ■ September 1997: Honeymoon couple Mark and Arnaz Erdmann spotted and photographed a coelacanth in a fish market in Manado, Indonesia. On 30 July 1998, Erdmann’s search for a second specimen paid off. Considered different enough from the African coelacanth to be a separate species, it was named Latimeria menadoensis. ■ 28 October 2000: Pieter Venter spotted a coelacanth towards the end of a training dive in Jesser Canyon off Sodwana Bay. On 27 November, Trimix divers returned to Jesser Canyon and filmed the first coelacanth colony sighted off South Africa. ■ 26 April 2001: First coelacanth trawled off the coast of Malindi, Kenya*. ■ February 2002: The then Minister of Arts, Culture, Science and Technology, Dr Ben Ngubane, announced the South African Coelacanth Conservation and Genome Resource Programme in Parliament. ■ Late 2003: The programme was renamed the African Coelacanth Ecosystem Programme (ACEP) to acknowledge regional involvement. The high expenses of offshore marine science meant that, to be globally competitive in the discipline, countries would have to draw on each other’s experience and resources. Dr Ngubane called the coelacanth the “NEPAD fish”, emphasizing ACEP’s role in fostering neighbourly relationships through science. ■ 6 September 2003: First coelacanth caught in Tanzanian waters, near Kilwa. Since the early discoveries, nearly 200 coelacanths have been caught in the Comoros Islands; 26 have been seen at Sodwana Bay, South Africa; over 24 are known to have been caught in Tanzania and over 6 in Madagascar; and 7 have been seen in Indonesia. Unconfirmed catch reports probably further raise the numbers for Tanzania and Madagascar.
Out of hiding Coelacanths remained hidden from western science because fishing methods in most parts of the world made catching them unlikely. They live in deep, rocky reefs. Only the people of the Comoros Islands with their nocturnal deep hand-lining technique (mazé) seemed familiar with the fish, which they call gombessa. Indonesian fishers reportedly call it raja laut or ‘king of the sea’, although their catches seem to have been with modern fishing gear, making this name relatively recent and perhaps a reaction to interest in the fish. The increasingly common catches result from modern fishing gear that reaches coelacanth habitats (particularly deep-set shark
gill-nets, called jarife in many parts of the western Indian Ocean) as well as improved communications around even poor, remote areas, where cellphones are surprisingly prevalent. In many cases (in Indonesia and Tanzania, for instance), it’s still western scientists or tourists that initially bring coelacanths to the world’s attention. For most people who catch them, they’re just another strange creature from the deep that’s not particularly good to eat. In three fishing villages near Tanga in Tanzania, at least 19 coelacanths were caught in a 6-month period – 6 in one gill-net overnight. * For details, consult L. de Vos and D. Oyugi (2002), “First capture of a coelacanth, Latimeria chalumnae, Smith, 1939 (Pisces: Latimeriidae), off Kenya”, South African Journal of Science, vol. 98 (2002), pp.345–347.
For more on the history of coelacanth discoveries, visit http://acep.co.za/ content/view/20/262 and http:// acep.co.za/content/view/21/2. Read about the early discoveries in J.L.B. Smith, Old Fourlegs: The Story of the Coelacanth (Longmans, Green & Co., London, 1956) and S. Weinberg, A Fish caught in Time: The search for the Coelacanth (Fourth Estate, London, 1999). Top: An attempt to resuscitate a coelacanth that had been caught by fishermen off Hahaya on Grand Comoro. Photograph: Chas Otway Middle: A still from a video taken of the first coelacanth seen on the very first Jago dive in Sodwana Bay in 2002. The fish is in a cave in Jesser Canyon, which we found occupied by coelacanths on most of our subsequent visits. Photograph: Courtesy Jago Team/ACEP Below: On display in the SAIAB foyer, a preserved coelacanth specimen from the Comoros. The picture shows some of the coelacanth’s teeth. The black objects (right) are labels that denote anatomical features of the fish for visitors. In the reflection in the glass on the right, the internal organs of the fish can be seen. Photograph: James Stapley
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ne a r C tled
Quick! Take a picture! ( they may not be around much longer.)
For over 30 years the Endangered Wildlife Trust has been dedicated to sustainable development and the conservation of the biodiversity of southern Africa. But we cannot do it alone. Without the support of our members, species such as the Wattled Crane, of which only 236 remain in South Africa, will march inexorably towards extinction.
Endangered Wildlife Trust www.ewt.org.za
Please help us continue to make a difference.
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To find out more about how you can actively support the EWT to conserve our countryďż˝s natural heritage, please call (+27) (0)11 486 1102 or visit our website at www.ewt.org.za Non-profit Organisation Registration Number 015-502NPO
PBO Exemption Number 930 001 777
1. We would like to understand the coelacanth’s physiology better but this is not possible without a specimen in captivity. We would also like to repeat some early work on the oxygen affinity of coelacanth haemoglobin, which forms the basis of much of the coelacanth’s assumed temperature tolerance range. 2. Details of ocean currents, water temperature, and other such parameters are also useful to biologists tracing the distribution patterns of various organisms, to people planning Marine Protected Areas and considering larval transport (see p. XX), and to researchers seeking to monitor, understand, and model the effects of climate change. 3. Marine charts are typically very poorly detailed below depths of about 50 m, as shipping is generally not affected by such depths and traditional hydrographic cruises virtually ignore them (visit http://acep.co.za/ content/view/359/295).
western and southern coasts are fairly well studied because of the fisheries’ interests there, but our east coast and the ocean to the north are effectively unknown to oceanographers. For a long time, one prevailing theory to ‘explain’ coelacanth distribution was to consider those individuals found outside the Comoros Islands as ‘deadend drifters’ – that is, hopeless swimmers swept to different parts of the channel from the Comoros by the powerful Mozambique Current flowing down the coast of Africa. Flow velocities in the area sometimes exceed 2 knots, which could rapidly transport a passive body trapped in the current over considerable distances, but research published in 2003 reveals a more complicated reality. Satellite altimetry data combined with current-meter readings from both moored and lowered acoustic Doppler current profilers (ACDPs) appear to overturn the earlier view of a continuous, linear, strong Mozambique Current. Satellite drogues that we deployed in the channel show what would in fact happen to a ‘hopeless swimmer’ in the area. The flow seems, after all, to consist typically of several large eddies (large spinning masses of water) travelling down the Mozambique Channel. Our long-standing misunderstanding of the region’s currents is a powerful reminder of the urgent need to research them further2. The provenance and inter-relatedness of coelacanths in Africa promises to be a topic of considerable scientific debate in the coming years. When ACEP began, we lacked even a rudimentary dataset for the area. ACEP has taken steps to rectify this shortcoming with 11 long-term temperature monitoring stations around the region (set up between 2002 and 2005) which already show surprising variability in the environment. Coral reefs, for instance, have been thought typically to have relatively stable temperature conditions and to require ▲ ▲
they’ve been seen staying in caves with ‘uncomfortably warm’ water of about 22 °C even when the temperature just outside these caves was around 18 °C. Depth doesn’t seem to be a requirement. Coelacanths have been captured in sea water as shallow as 40 m in Tanzania. Cooler waters are found relatively deep in their tropical homes, but they sometimes venture into relatively shallower waters (that is, above 100 m) if they find cooler water there1. The mountain of information that’s been collected is coordinated in a geographic information system (GIS) database, so researchers can examine the spatial relationships of the data with reference to findings in other disciplines that might be directly related. Spatial databases are generally founded on a detailed topographic map (or digital elevation model). Unlike terrestrial topography, which is generally well known and can easily be supplemented with aerial photography or satellite imagery, the seafloor is poorly documented3. The first ACEP cruise in 2002 used ‘multibeam swath bathymetry’ to prepare detailed charts of the canyons of the Greater St Lucia Wetland Park. This technique uses an array of sonar (sound) ‘beams’ as the basis for a detailed picture of the bathymetry (that is, the topography) of a swath, or strip, of seabed. Combining data from several swaths makes it possible to create a detailed and accurate map of the bottom contours of a larger area. This level of detail is becoming increasingly important in guiding remotely operated vehicles (ROVs) and submersibles accurately to interesting seabed features, and helps to maximize the return on expensive and limited research-cruise time. Understanding the ocean floor also gives information about the habitats of many other organisms. It also helps with modelling the oceanography of the region, as the seabed interacts with currents and can affect conditions in important ways. South Africa’s
Top: A satellite-tracked drifter buoy released near the Comoros illustrates the path of a ‘helpless drifter’ in the prevailing currents of the Mozambique Channel. If this were a ‘helpless’ coelacanth ‘trapped’ in the current, it would have been spinning around in the channel for over 9 months. These data illustrate the eddies that dominate the flow in the region. Image: M.J. Roberts, Ocean Research Africa (www.oceanafrica.com)
Above: The satellite drogue (or funnel-like device) being released. The blue fabric ‘sock’ sinks under water, ensuring that the buoy is more influenced by current than wind. Photograph: James Stapley
Nets of death Many rare marine animals are victims of fishing ‘bycatch’, that is, they are caught unintentionally by fishing practices that target other kinds of fish for food. Bycatch causes the deaths of many rare and endangered species (see also pp. 7–8) including coelacanths. Some 32 coelacanth catches from deep-set gill-nets have now been confirmed and several more reported – all from deep-set shark gill-nets. ■ A deep-set net is deployed (or ‘set’) in fairly deep water (more than 100 m down). ■ A gill-net ensnares animals that stumble into it, typically by allowing the head to travel into the net’s mesh but not back out of it again, as the fish’s gills or other body parts get stuck and trap it in the net. ■ Drift-nets – widely publicized by Greenpeace and others as ‘walls of death’ for their ability to kill huge numbers of sea creatures such as turtles and dolphins as bycatch – are a type of gill-net. Drift-nets float freely through the ocean while ‘set’ nets are fixed in a particular place on the seabed. Deep-set nets are increasingly used around the western Indian Ocean, mainly to catch sharks for the lucrative shark-fin trade. Such nets have caught coelacanths in Indonesia, Madagascar, and Tanzania.
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year-round temperatures above 20 °C, but our records show surprisingly large, and often sudden, variations in temperature of 16–30 °C, and temperature swings of more than 10 °C in just a few hours. Temperatures higher than 30 °C can stress corals and cause bleaching. Sodwana Bay’s coral reefs are the most southerly in the world, so they’re probably tougher than most, but some from further north are showing similar variability. Life and death numbers What of our icon, the coelacanth? How many are there? And where? We’ve identified a total of 26 individual coelacanths from the Sodwana Bay area. Further to the six coelacanths filmed by the divers who first discovered them in 2000, submersible surveys using the German submersible Jago and its team (Hans Fricke, Karen Hissmann, and Jürgen Schauer) found another 17 specimens. A brief trial using an ROV sighted another two. In 2004 there was a most surprising sighting by divers at a depth of only 54 m on the scattered reef inshore of Diepgat Canyon, south of Jesser. Submersible surveys of Diepgat Canyon itself did not reveal any coelacanths. Bottom temperatures were reported as 18–19 °C, well within the assumed temperature tolerance range for coelacanths. The sighting, therefore, was surprisingly shallow, as coelacanths are generally assumed to live in quite deep water (more than 90 m deep), and, furthermore, water inshore at Sodwana Bay is generally too warm for them. The explanation was a rare strong upwelling of cold sea-water. An
eddy feature off the shelf near Sodwana Bay would have transported warm shelf-water offshore, replaced, in turn, by an upwelling of cool, deeper water. A 10-year temperature record at Nine Mile Reef shows such strong upwelling events to be rare4. Our partner countries have also seen coelacanths in their waters, although, regrettably, only through accidental bycatch (see box). The fishery operating from several fishing villages near Tanga in the north of Tanzania has been the site of most of the catches, and an unprecedented number of coelacanths have been captured in a short space of time. ACEP is currently in the planning and fundraising stages of a project to investigate the creation of a marine protected area (MPA) in the Tanga region to prevent further catches and to study the live coelacanths in situ5 – as well as to protect the rest of the marine environment there. Counting live coelacanths is no easy task, but surveys conducted by the German team over several years estimated that the cave population off the coast of Grand Comoro Island is between 250 and 600 animals. This range is wide, as coelacanths defy traditional fishery population estimation techniques in their distribution and behaviour, and assessing their numbers accurately is difficult. Random sampling of an area doesn’t work – sampling non-cave habitat is pointless, as coelacanths simply won’t be there. On land you can survey all the elephants in a park from an aeroplane, for instance – but you can’t sample all the underwater caves simultaneously in a single day (even if you knew
Exercise mark–recapturing to estimate fish numbers
Top: Still picture from video footage obtained by Trimix scuba-divers in Jesser Canyon, Sodwana Bay. These intrepid divers first alerted us to the unexpected presence of these ancient fishes, alive and well, off our coastline. Photograph: Christo Serfontein (www.coelacanth-diver.co.za/)
Middle: The anal fin of a preserved coelacanth on display at SAIAB. The bluish grey colour that coelacanths have in life has faded to a dull brown. All fishes lose their bright colours after immersion in preservatives. Photograph: James Stapley
Below: The first dorsal fin of a preserved coelacanth on display at SAIAB. In living coelacanths, the membrane between the stiff fin rays is smooth and continuous; this one was damaged during capture. Photograph: James Stapley
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To assess the overall number of a fish population, researchers often mark a sample of individuals and release them back into the water. Later, they’ll take further samples, count the number of marked fish relative to unmarked fish, then use the result to estimate the total. This method only works when the fish population moves about randomly in the population in the area from which you’re sampling. Here’s an exercise to see how the method works. ■ Take a bucket or bag of marbles. ■ ‘Catch’ some of the marbles and paint them. ■ Return them to the bucket or bag. ■ Stir all the marbles well (as though they were fish moving around under water). The stirring distributes the coloured marbles randomly within the greater marble population. ■ Now take another random sample (or preferably several). The incidence of painted marbles relative to unpainted marbles in your sample(s) gives you a good starting point for calculating how many marbles there are in the bucket as a whole (or fish in the sea/lake/pond). ■ Try doing the calculation. (NOTE: To check the accuracy of your calculation you can count the total number of marbles in the bucket. This method of checking is not available to researchers!) (See also http://en.wikipedia.org/wiki/Mark_and_recapture) 4. The scientific details may be found in M.J. Roberts et al.,“Oceanographic environment of the Sodwana Bay coelacanths (Latimeria chalumniae), South Africa”, South African Journal of Science (2006), vol. 102 (in press). 5. There have been further coelacanth catches off the south-eastern coast of Madagascar near Toliara, and a similar study is proposed there with the aim of setting up a further MPA. The third MPA under investigation in the near future is off the coast of Grand Comoro Island.
Temperature (ºC) 0
0 200 400
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Ocean Data View
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where they all were). You can’t use a mark–recapture exercise to assess their numbers, as coelacanths seem to stay put in their caves rather than moving around as many other fish do (which is a pity, as individual coelacanths have unique spot patterns, which are as individual as our fingerprints). Studying living coelacanth numbers, in fact, has been likened to trying to find lions hiding in caves, at night, in the fog, from a Land Rover with a top speed of 3 km/h, in the space of no more than a week! Working with the German team, ACEP researchers spent 166 hours at the bottom of the sea in the Jago in three years of submersible dives – that’s just under a week of continuous study time, not all of it spent in front of coelacanth caves. We don’t know how many caves there are in total – or why some caves were occupied more than others and others apparently never occupied at all. The estimates off Grand Comoro Island were calculated by multiplying the number of individuals seen in one stretch of coastline by the entire length of the island’s coastline. The estimate depends on which dataset you use, as numbers vary each year and extrapolations can be done in more or less conservative ways, but the likeliest number is thought to be 300 or less. Studying coelacanths – and, more broadly, their habitats, environments, and the life that surrounds them – needs a new generation of scientists and technicians supported by modern research equipment. South Africa’s position, bathed by three oceans, makes it uniquely placed to be a global centre for these studies. ■ James Richard Stapley is Scientific Communicator, African Coelacanth Ecosystem Programme, South African Institute for Aquatic Biodiversity.
Above: Cruise track data showing oceanographic data gathered on a cruise in 2003. The GAT (Great African Transect) section follows the Eastern African mainland from South Africa (Kenton-on-Sea) to near Latham Island, Tanzania. MoCoMa (Mozambique–Comoros–Madagascar) is data from the northern part of the channel. GMT (Great Madagascar Transect) shows data from the west coast of Madagascar, Nosy Iranje to Toliara. Finally, MaBasMo (Madagascar–Bassas da India–Mozambique) shows the southern part of the channel. The grey section indicates bottom depth, when within the scale of the plot. Such data are vital to understanding the region’s physical oceanography. Image: M.J. Roberts, Ocean Research Africa (www.oceanafrica.com/) Below (top): False-colour, sun-shaded topographic model created from swath bathymetry data collected in 2002 from the canyons of the Greater St. Lucia Wetland Park. Image: P. Ramsay, Marine GeoSolutions/ACEP Below (right): Fish markets, such as this one in Maputo, rely on fisheries based on ecosystems closely linked to coelacanths, so fishing pressure on the region’s coastal resources is increasing. Photograph: James Stapley
Above: Researcher Kerry Sink sorting biological specimens collected off the west coast of Madagascar. Photograph: James Stapley
For more information, visit the ACEP website, www.saiab.ru.ac.za/ acep/. See also P. Venter et al. “Discovery of a viable population of coelacanths (Latimeria chalumnae Smith, 1939) at Sodwana Bay, South Africa”, South African Journal of Science, vol. 96 (2000), pp.567–568 (a digital version can be found at http://fishwatch.tripod.com/ coelacanth/philarticle.htm).
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Still counting SAIAB researchers Paul Cowley and Alan Whitfield have grappled with ways to count fish and find out what they do at different times of their lives, how they move about, and in what ways they act as indicators to anyone wanting to assess the health of an area. Technology to track fish movements
Top: Aquatic biologist Roger Bills examines a specimen in the SAIAB National Fish Collection. Photograph: Hywell Waters
Middle: Marine biologist Nadine Strydom and a colleague check a larval seine net. A seine net is a large fishing net that hangs vertically in the water, with floats at the top and weights at the bottom. Photograph: Serge Raemakers
Below: Sorting a catch on deck.
24 Quest 3(1) 2006
Photograph: James Stapley
Paul Cowley Provided they’re large enough, terrestrial animals are much easier to track than fish. Using observation, scientists can reasonably easily investigate their daily movements and even their migrations. Monitoring ‘out of sight’ underwater creatures is a lot more difficult and has challenged scientists for decades. Fish movement and migration studies have traditionally meant catching, tagging, and releasing hundreds of individuals, in the hope that some would later be recaptured. But recaptures from such projects yield limited data. You might discover that an individual ended up 200 km away from where it was tagged, but know nothing of what it did in between, how long it spent in specific habitats, how often it returned to specific sites, or whether the 200-km trip was a regular return migration or a consequence of nomadic wandering. Electronic tags (transmitters) and receivers have become more affordable and they’re now a popular way of studying the activity patterns, movements, habitat use, and migrations of fishes and other aquatic organisms. How telemetry works The technology of telemetry (that is, using instruments to transmit radio signals over a distance) can be used in two ways. First, researchers can sit in a boat and manually track fish equipped with transmitters. They use a handheld directional hydrophone (receiver) that identifies a unique signal (a ‘beep, beep, beep’ sound) for each tagged fish. In this way, they get highresolution real-time tracking data about the whereabouts of individuals. Owing to the frequent ‘pinging’ required to track the fish, however, battery life is
relatively short (1–2 months). Second, researchers can monitor fish movements within a defined area (such as a coastal bay) by using an array of moored data-logging listening stations. These record the presence (or absence) of tagged fish within a multidirectional reception range, which, under good conditions (no currents or wind action), can be up to one kilometre. This kind of telemetry system requires transmitters that ping less frequently, so battery life can be extended to more than a year. The type and size of transmitter used depends on the size of the fish under investigation and on the questions that researchers want to answer. Transmitters can be as small as 7 mm in diameter and used on fish smaller than 20 cm long. The transmitter is normally attached to an anaesthetized fish through a surgical implant into its abdomen. Transmitters can also be equipped with depth and/ or temperature sensors to provide data not only on an animal’s position but also on its vertical movements (dives) and its thermal history. Discoveries The value of understanding the movements of aquatic organisms extends far beyond satisfying scientific interest. Real-time telemetry data can help to answer critical management questions. Do migrating species pass obstructions (for example, weirs) in river systems? What types of habitat must be protected to conserve endangered species? Is a given marine reserve big enough to protect a species throughout its life cycle? In addition, telemetry has been applied within the aquaculture industry to optimize commercial production and assess fish welfare. In South Africa, telemetry has helped researchers to study important fishery species, such as dusky kob, white steenbras, and spotted grunter, which depend on estuarine environments to
about half of the time within the protected (no fishing) zone. Despite the abundant food organisms on shallow sand banks, the tagged white stumpnose rarely moved out of the lagoon’s deep channel areas. ■ A satellite telemetry study on white sharks (Carcharodon carcharias) revealed that one individual undertook transoceanic migration to Australia and back! Telemetry has become a valuable tool for scientists wanting to understand more about the mysterious lives of aquatic organisms and to help to conserve them and their natural habitats. Dr Cowley leads several projects that investigate the abundance, habitat use, and movements of important estuarine and coastal fishery species. As a keen angler, he is one of those fortunate scientists who have married hobby with work interests. For reports on the findings of these and other telemetry studies visit www.ru.ac.za/academic/ departments/difs/BRG.
A proudly South African Fish Community Index Alan Whitfield Environmental awareness is growing round the world and water resource managers are demanding more and more ecological information on which to base their planning and decisions. They often need it in a form that’s easy to understand and use, which means distilling the complexities of the environment and simplifying the information in ways that are still scientifically valid. South Africa can boast of inventing – and exporting – a novel way of preparing this kind of
Top left: Taken in the early morning on a part of the coast followed by the Tsitsikamma Otter trail, the first line cast on the fourth day of a bi-annual tag and release programme run in the Tsitsikamma Reserve by Paul Cowley. Photograph: Lee-Ann Knowles Top right: Seine-net sampling (Mtana Estuary, Eastern Cape) is part of the work for the new Estuarine Fish Community Index. Photograph: Alan Whitfield Above: Oblique aerial view of the Sezela Estuary where the new index was tested. Photograph: Alan Whitfield
information for estuarine managers: the Estuarine Fish Community Index (EFCI). Working with indicators A good way to evaluate an area’s basic health without having to capture all its details is to use indicators. In aquatic ecosystems, these have typically included physical, chemical, or biological measures. Biotic indicators (such as invertebrates, fishes, or birds) generally work well as indicators of aquatic ecosystem health, because they integrate the effect of several different environmental factors, such as water quality, habitat, and biological interactions. Fishes have been used extensively and meaningfully as indicators of environmental change in North American streams and rivers, but their use in estuaries is still in its infancy. The EFCI, developed in South Africa, is only the second index of this type in the world and the method was made public just two years ago, in 2004. It is based ▲ ▲
complete their life cycles. Here are some important discoveries. ■ Juvenile spotted grunter (Pomadasys commersonnii) stay faithful to particular sites and occupy distinct home ranges within sections of the estuary. Most of these home ranges overlap and correspond with areas where food (mud prawns) is most abundant. Some individuals occasionally abandon their home ranges, however, and move into the marine environment. In the research study, these temporary migrations were related to environmental changes – of temperature, for instance, and salinity. ■ Juvenile white steenbras (Lithognathus lithognathus) displayed similar resident behaviour. The tagged fish were strongly associated with shallow sand banks, mostly in the mouth region of the estuary. ■ Juvenile dusky kob (Argyrosomus japonicus), by contrast, made regular excursions up and down the estuary, spending approximately even proportions of time at different locations, from the mouth to 8 km upstream. These horizontal movements were correlated to tidal movements – the fish moved upstream with the flooding tide and downstream with the ebbing tide. ■ White stumpnose (Rhabdosargus globiceps) in Langebaan Lagoon were the subject of an independent study, in which researchers tracked the fine-scale movements of the fish to understand how the sanctuary area of the West Coast National Park might help to protect this commercially important species from over-exploitation. Preliminary findings suggest that this species uses the lagoon extensively and spends
1. We were able to construct reference fish communities for each region only because of the 1990s fish surveys that had been conducted between the Orange (Gariep) and Kosi estuaries.
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By comparing the actual community within an estuary with the appropriate ‘reference’ community Physical
...one can measure the relative health of that estuary. Above: Diagrammatic representation showing that the fish community in an estuary is dependent upon and affected by its physical, chemical, and biological environment.
Help to restore the ocean’s bounty A recent landmark paper* paints a gloomy picture of reduced marine biodiversity accompanied by plummeting catches of wild fish and declining water quality. All commercial fish and seafood species could collapse by 2048, the authors claim. With public support, the situation can improve. The study found that, consistently, higher diversity of marine plants or herbivores across 32 small-scale experiments came with benefits such as greater ecosystem stability and 80% more biomass. Data for 64 large marine ecosystems showed that fisheries are collapsing at a higher rate in species-poor ecosystems than in species-rich ones. The public can help restore the ocean’s bounty by eating seafood that’s abundant and avoiding species in decline. The answer is widespread responsible consumption. ■ Buy (and enjoy) – angelfish, butterfish, hake, oysters, sardines, snoek, tuna (except bluefin tuna), white stumpnose, yellowtail, and others on the “green” list. ■ Reduce consumption of – abalone, kingklip, kob, marlin, red stumpnose, sole, swordfish, and others on the “orange” list of fish under pressure. ■ Avoid completely – Cape and Natal stumpnose, perch, rock salmon, spotter grunter (tiger), white musselcracker, white steenbras, and others on the “red” list of fish that it’s illegal to buy or sell in South Africa (though they may belong to allowable ‘recreational fishing under permit’) because stocks are so low. * The paper, “Impacts of biodiversity loss on ocean ecosystem services” by Boris Worm et al., appeared in Science of 3 November 2006.
For more on responsible consumption of seafood, visit the Southern African Sustainable Seafood Initiative (SASSI) at www.wwf.org.za/sassi. ▲
on 14 metrics or measures that represent four broad fish-community attributes: species diversity and composition, species abundance, nursery function, and trophic integrity. First we needed to derive reference conditions and metric thresholds against which later to compare other fish communities living in the same region but in different conditions. To this end, fish community data were collected during an extensive national study in the 1990s that covered more than 200 estuaries around the country1. Fish species composition is a particularly good measure of an environment’s health. To develop baseline reference conditions,
26 Quest 3(1) 2006
researchers documented a typical fishcommunity structure for a particular type of estuary in each region. In a small, intermittently open estuary in the subtropical region of KwaZulu-Natal, for instance, the fish community structure or composition has a different ‘reference community’ from that of the same type of estuary in the Eastern Cape, which is in a warm temperate region. When an estuary in either region becomes polluted, it is likely to lose species. As a result, the stressed fish community deviates from the reference community for that particular region. The term ‘metric thresholds’ is used to refer to the values allocated to the extent to which a stressed fish community deviates from the reference fish community. EFCI success To evaluate the individual EFCI metrics and make sure the index was accurate enough, we collected data from the Sezela Estuary, a degraded KwaZuluNatal system where rehabilitation measures had been implemented. Happily, the evaluation of the Sezela fish community during the recovery phase of this estuary indicated that the selected metrics did indeed reflect improving conditions adequately. For example, the index increased from a score of 30 (poor) in October 1984, when the Sezela Estuary was badly polluted, up to 46 (good) in August 2001, after much of the pollution had been removed. Immediately following a single pollution event in January 2002, the index declined to 38, indicating the fish community’s response to changes in water quality. In 2006 the EFCI was applied to the data collected from South African estuaries during the 1990s nationwide survey. This new method has therefore provided a measure of baseline ecological conditions existing
within these systems during the 1990s, against which future environmental monitoring can take place. Now we need to train selected aquatic scientists and environmental researchers to apply and use the index. It means acquiring the appropriate fishing gear at selected sites countrywide, and running fish identification courses for prospective participants who will apply the EFCI to estuaries under their jurisdiction. Success will help South African managers, policy-makers, and conservationists to answer practical questions about managing the estuaries for which they are responsible, and it will help them to use these estuaries sustainably. To our delight, the EFCI has become internationally recognized as an important new estuarine indicator – it is already the basis for a fish community index that UK researchers are developing to monitor the health of their estuaries, and further enquiries have come from scientists in other parts of the world as to its possible applicability to estuarine waters in their countries. Dr Whitfield is Research Manager and a Principal Aquatic Biologist at SAIAB. He has studied the biology and ecology of fishes in South African estuaries for more than 30 years and is particularly interested in conducting research that is relevant for the conservation and wise utilization of fishes in estuaries. Find more information in the following articles: S.A. Bortone, W.A. Dunson, and J.M. Greenawalt, “Fishes as estuarine indicators”, in S.A. Bortone (ed.), Estuarine Indicators (Boca Raton, CRC Press, 2005), pp.381–391; T.D. Harrison and A.K. Whitfield, “A multi-metric fish index to assess the environmental condition of estuaries”, Journal of Fish Biology, vol. 65 (2004), pp.683–710; T.D. Harrison and A.K. Whitfield, “Application of a multi-metric fish index to assess the environmental condition of South African estuaries”, Estuaries and Coasts (in press); A.K. Whitfield and M. Elliott, “Fishes as indicators of environmental and ecological changes within estuaries: a review of progress and some suggestions for the future”, Journal of Fish Biology, vol. 61 (Supplement A)(2002), pp.229–250.
Citizen science – the East Coast Fish-Watch Project Phanor Montoya-Maya, and Phil and Elaine Heemstra Each time divers, anglers, and other amateur ichthyologists photograph or record the fish they see and the data of the fish and the sighting (size, behaviour, depth, habitat, locality and date), and send the information and photographs to the East Coast Fish-Watch Project (ECFWP), they’re contributing to our knowledge of the fish fauna and helping
with the long-term monitoring of our fish communities. Collaborations of recreational divers with scientists enlarge the sampling effort, the collection of data, and geographic coverage. The research that follows (analyses of fish communities, species distribution, migration, and ecology) is essential for conserving and managing our fish diversity. Citizen science (or volunteer data collection) is widespread where scientists and resource agencies with limited funding need information and where trained volunteers can help to collect it. Scuba divers, for instance, train through our Fish-Watch dives (an open ocean training session in fish identification) or by self-learning from our worksheets (illustrated waterproof underwater identification sheets with text that gives information about the fish). Using this knowledge on their dives, volunteers gather and pass on information from different parts of South Africa. Sodwana Bay (in KwaZulu-Natal) has about 26 000 divers who do some 80 000 dives every year. Just 1% of these divers participating in the project could substantially improve our understanding of this fish community. The ECFWP’s value and potential for diver education, increasing appreciation of fish diversity, and awareness of science is becoming more and more apparent. The core
of about 100 members is already improving our knowledge of South Africa’s marine fish fauna. ■ In the past decade, we’ve found more than 50 new records (that is, fishes not previously known from our coasts) of moray eels, gurnards, cardinalfish, fusiliers, damselfish, wrasses, gobies, soles, triggerfish, and pufferfish. ■ The clinid fish Pavoclinus caeruleopunctatus was photographed, collected, and described for the first time by diver and Fish-Watch member Guido Zsilavecz with Phil Heemstra’s assistance. ■ Dennis Polack sent in a photograph of the blackspot goatfish (Parupeneus pleurostigma) from Sodwana, which turned out to be a new distribution record; in his revision of the goatfish genus Parupeneneus, Jack Randall, a Honolulu-based ichthyologist, used the photograph as the basis for this new distribution record for South Africa. In the past ten years, more than 100 new (that is, previously undescribed) species of marine fishes have been found in southern Africa. But with some 1 800 coastal fish species, we still have much to learn about our as yet poorly known marine fish fauna. With the help of citizen volunteers, we’ll undoubtedly increase our knowledge of the Western Indian Ocean fish diversity. ■
The East Coast Fish-Watch Project (ECFWP) The East Coast Fish-Watch Project was founded by ichthyologist Phil Heemstra and Dive Charter manager Mark Addison in 1998 and is conducted by SAIAB. Through it, scuba divers, anglers, and scientists work actively together to learn more about fishes. The project’s three complementary components are: ■ scuba-diver participation and education ■ survey of marine fish diversity ■ creation of an East Coast FishBase. The project reaches South Africans as well as divers from other Western Indian Ocean countries. As willing members, they’ve even sent pictures of fishes from their own countries for us to identify. The ECFWP is planning a community-based programme to monitor alterations in fish communities resulting from environmental change. A long-term monitoring system using the recreational diving community to track changes will contribute to the study. To establish the programme, we need to develop ■ a Fish-Watching continuing education system ■ a Fish-Watching communications campaign ■ a web-based fish database updated by Fish-Watchers. The monitoring scheme aims to be enjoyable as well as scientifically robust, attracting people wanting to learn more about fish and to promote conservation of fish diversity. Becoming a Fish-Watcher with the ECFWP is easy. You can start by observing the fish in the tidal pools next time you go to the beach. No matter if you’re a certified scuba-diver or not, you’ll need a mask, snorkel, and fins to help you to observe. With a fish identification book, you can later check the names and descriptions of what you’ve seen. Divers, anglers, aquarists, and anyone interested in marine fish can join the project. Visit our website at http://fishwatch.tripod.com.
Above: These two clinid fish were previously identified as a single species, the peacock clinid Pavoclinus pavo (Gilchrist & Thompson 1908). Guido Zsilavecz, diver and Fish-Watch member, recognized the different blue colour patterns on the head and other features that distinguish the two species; with the assistance of Phil Heemstra, he described a new species, Pavoclinus caeruleopuntactus Zsilavecz 2001. The bluespot clinid, P. caeruleopunctatus (above), has blue spots behind its eyes whereas, the peacock clinid (top) has blue lines. Photograph: Guido Zsilavecz SAIAB’s Phanor Montoya-Maya is a marine biologist and scuba diving instructor with experience in developing educational and outreach marine activities for divers in the Caribbean. Phil Heemstra is a leading ichthyologist and Elaine Heemstra is a scientific illustrator – both with a commitment to sharing fish science with people. Whether you are a volunteer or a professional, for details and illustrations keep consulting Phil and Elaine Heemstra's, Coastal Fishes of southern Africa (South African Institute for Aquatic Biodiversity and National Inquiry Service Centre, Grahamstown, 2004). Two other organizations conducting citizen science of this kind are Reef Check and Reef.
Scalloped glassfish (Ambassis nalua), found in the Indo-West Pacific. Artwork: Elaine Heemstra
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Careers in S&T Q
Work in aquatic biodiversity So, you want to work with living things associated with water? Vanessa Rouhani has a few suggestions. Left: SAIAB ‘Bright Spark’ youngsters captivated by the sea life in the Two Oceans Aquarium. Photograph: Courtesy of SAIAB
Below: Collections Officer Jerraleigh Kruger unpacking a large fish from a tank in the SAIAB National Fish Collection. Photograph: Courtesy of SAIAB
Bottom: Launching the Jago submersible. Photograph: James Stapley
he most popular careers of this kind include those of marine biologists (this is a general term and can include many different kinds of work), ecologists, fishery scientists, and oceanographers, as well as many others. They all centre on the concept of biodiversity. Biological diversity – or biodiversity – refers, in effect, to all life on our planet. Aquatic biodiversity is all life in water. Scientists often describe biodiversity in terms of species diversity, which refers to the variety of species within a region, or genetic diversity, which refers to the variation of genes within species, or ecosystem and community diversity, which includes the relationships among species and their habitats. ■ Marine biology deals specifically with the plant and animal life found in all habitats associated with the ocean, from coastal estuaries to the deep sea. Marine biologists study the distribution, abundance, behaviour, life cycles, and ecology of various organisms, from plankton (microscopic plants and animals) to whales and seabirds. Marine biologists normally work in a speciality research field. A degree in marine biology is offered by the universities of Cape Town, KwaZulu-Natal, and Fort Hare, Nelson Mandela Metropolitan University, and Walter Sisulu University. Studying marine biology opens up career opportunities in zoology, ichthyology, fisheries science, oceanography, and marine resource conservation. ■ An ichthyologist studies the fundamental aspects of fish biology, taxonomy, and ecology, whereas a fisheries scientist performs research on the fish populations that people harvest through fishing.
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The South African Institute for Aquatic Biodiversity (SAIAB), in partnership with Rhodes University’s Department of Ichthyology and Fisheries Science, forms the only major African centre for the study of fish and the training of graduates in ichthyology, fisheries science, and aquaculture (the farming of fish and other aquatic creatures in water). A degree in Ichthyology or Fisheries Science offers several career possibilities, including fish research, fisheries and aquatic resource management, conservation, teaching, environmental education, environmental consulting, rural development work based on natural resources, environmental journalism, the fishing industry, eco-tourism, and fish farming. Ichthyologists in research and teaching posts are employed in museums, universities, research institutes, public aquariums, and conservation departments. There are self-employment opportunities in eco-tourism and in consulting work related to ichthyology, conservation, and management. Aquaculture is a rapidly growing industry, with many fish farms being run as small businesses, supplying fish to fish hobbyists and also growing food-fish availibility.
What skills, interests, and aptitudes do you need? You need to be interested in nature and living organisms. You also need a questioning mind; powers of close observation; patience and perseverance; and physical stamina (if you have to do fieldwork in rough conditions). You need to be an independent person as well as having good group- and teamwork skills; you need to be a good communicator (that is, to be good at writing, talking clearly, analysing, and explaining); and you need to be practical, precise, accurate, logical, and methodical.
How can you qualify? Important school subjects: Biology, Mathematics, Physical Science. Qualifications: B.Sc. (Natural Sciences/ Biological and Life Sciences), B.Sc. (Honours), and M.Sc. In most countries worldwide, a minimum qualification of an M.Sc. degree is needed to enter the field of aquatic biodiversity research, but a Ph.D. is even better. In total, this can mean 6–10 years of studying. ■ Vanessa Rouhani is a science communicator at SAIAB and is involved in education outreach and public awareness of science.
Q Your Q UEST ions answered
Laying waste to aliens QUESTION
The Working for Water programme has laid bare large areas of land that had previously had vegetation. What is the strategy for replacing the plants that were removed? When are we likely to see new growth? Also, when invasive alien plants are cleared, what’s done to make sure that roots are properly destroyed and no seeds are left behind? From a Capetonian mourning the departure of favourite pines
ANSWER The goal is normally to return the area either to a cover of viable natural vegetation or to a productive crop. For natural vegetation, one usually relies on natural succession, based on recolonizing the site from seeds stored in the soil, existing plants, and species that disperse into the site from elsewhere. The extent to which this succeeds depends on the area (some vegetation types recolonize better than others), the type and density of alien plants at the time of clearing, and the length of time they have been there (the denser and the more established they are, the less successful the recolonization will be). There have been some spectacular successes, but also some failures. In some cases, the Working for Water programme has instituted rehabilitation projects (where the cleared area is actively replanted), but these are not widespread. While your reader should not expect an instant return to natural vegetation, it is possible that (given time) good cover will return. This aspect of the process, however, requires more attention and more research. The best option is for people to engage with the programme in their area to find solutions. Where fynbos is concerned, there are many examples where clearing has led to the recovery of native fynbos in good time – not easily imaginable when people contemplate the bare ‘moonscape’ immediately following a clearing operation. The question regarding roots and seeds is more complex – much depends on the species. Pines and hakeas, for example, are killed when they’re cut down and their roots simply die and rot away. Even though dead, these trees still have viable seeds, Left: 1996 – Closed stands of 8-year-old pine and hakea being felled as part of the Working for Water programme, above Villiersdorp in the Western Cape. Middle: 1999 – There was good fynbos recovery after an unplanned fire had cleared the area in February 1997 and, by the time this picture was taken in 1999, the site was dominated by short-lived fynbos shrubs such as the Ursinia palacea (in flower), which are mostly short-lived (with a life of 4–5 years) and highly prominent in the first few years after a fire. Right: 2003 – By now, the fynbos vegetation had matured. It was dominated by many species of restios (commonly known as Cape reeds) with a few tall emergent Proteaceae (Leucadendron microcephalum), which do not have soil-stored seed banks and which had managed to introduce itself back into the area. Photographs: Patricia Holmes
so one would follow such a clearing operation with a fire to kill seedlings before they mature. This method is very effective. For Australian acacias, on the other hand, a different approach is required. Stumps that have been cut down normally sprout, so they are treated with herbicide to kill the roots. Also, these species build up considerable seed reserves in the soil and several follow-up clearings are needed to remove seedlings. Dr Brian van Wilgen, CSIR Natural Resources and the Environment, Stellenbosch
ANSWER Rehabilitation is a complex process and many factors have to be taken into account. Take the case of mountain fynbos, for example. If mountain fynbos has been densely invaded by alien vegetation for one or two fire cycles only, and if the invasive plants have been cleared before the fuel-load is too great, then clearance followed by the restoration of indigenous conditions can return the cleared area to its original state within 5–10 years or so. But if the fynbos is densely invaded for more than two fire-cycles, the fynbos seed-banks in the soil decline, and successful natural recovery is less assured. Furthermore, if the aliens create a high fuel-load (such as, for example, a dense stand of pine or hakea that’s more than 15 years old), and if this is felled and then burns in hot conditions, the fynbos seed-bank could be destroyed. There are success stories, however. The area above Villiersdorp comes to mind, where we set up monitoring plots with Working for Water in 1996. The ‘before and after’ pictures reproduced here tell the story! Dr Patricia Holmes, biophysical specialist in the Environmental Resource Management Department, City of Cape Town Brian van Wilgen is a Chief Ecologist at the CSIR and was scientific advisor to the Working for Water programme. Plant ecologist Patricia Holmes has assisted the programme in monitoring the impacts of alien clearance on fynbos in the mountain catchments in the Western Cape. Send your questions to the Editor (write S&T QUESTION in the subject line) by e-mail to firstname.lastname@example.org OR by fax to (011) 673 3683. Keep questions as short as possible, and include your name and contact details. (We reserve the right to edit for length and clarity.)
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Books Q Far left: Poor man’s cycad (Encephalartos villosus). Known as ‘living fossils’, cycads have hardly changed since the age of the dinosaurs. Photograph: Geoff Nichols Left: The front cover of the book features a tree-fuchsia (Halleria lucida). Photograph: Guy Upfold
Forest Plants in the Forest and in the Garden. By Elsa Pooley (Durban: The Flora Publications Trust, 2006). ISBN 0 620 37012 2
Exploring biomes T
his is the first (beautifully presented and illustrated) portable, affordable book in a new series of guides to South Africa’s biomes or, broadly speaking, vegetation types. It’s perfect for beginners and members of the general public wanting a handbook as they explore their natural surroundings, wherever they may be. Biomes are part of the school syllabus, yet there is little accessible reference material relating to them, explains author Elsa Pooley. The books will also be “a great souvenir for tourists to the country”, their format allowing for photographs to “show off our wonderful plants and provide notes for growing interest in indigenous gardening.” Forests make up the smallest of South Africa’s nine biomes and cover just 0.5% of the country’s total surface area. Situated mainly in the southern and eastern areas, forests vary greatly in their species diversity and structure. Many giant trees were felled for timber from the 1800s to the 1940s. Now, although many forests are totally protected and some are well managed, they remain threatened and are still being destroyed. All need to be cherished and conserved. Every plant is involved in the health of an ecosystem, its animals, insects – and people too. Removing giant trees makes way for non-timber species; clearing the understorey allows aliens to invade and destroy indigenous plants. Loss of food plants for insects means loss of pollinators. “We need to be aware that every action has consequences,” says Pooley. These biome books cannot be comprehensive, but they introduce the plants of smaller areas, all together in one volume “rather than artificially separate[ed] into trees,
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Top: Juvenile scarlet-chested sunbird (Nectarinia senegalensis) feeding on Scadoxus puniceus. Photograph: Guy Upfold
Above: The forest raisin or shaggy raisin (Grewia lasiocarpa) is endemic to the Eastern Cape and KwaZulu-Natal and found on forest margins from coast to mistbelt. Photograph: Geoff Nichols
flowers, grasses”. The 110 or so species in this first one are carefully selected to include plants with the widest distribution in all forests from the Western Cape to Limpopo. The author wanted “the wonderful pictures and glimpses of habitat [to] encourage a greater interest in our forests. By including some of the birds, animals, and butterflies …, we hope[d] to ‘paint’ a more complete
picture of the biome.” Having worked with plants for four decades, Pooley and photographer Geoff Nichols had the reference base to put this book together relatively quickly. They’re actively involved with plants in all kind of ways – including indigenous landscaping, rehabilitation work, painting, photography, writing, leading botanical tours. For Pooley, the series is “a public relations effort for plants and their habitat – something I am passionate about.” Geoff Nichols, who provided most of the photographs, was one of the first plant photographers to convert to digital images and has used his comprehensive collection of pictures for his own books and his landscaping work. He describes his experience of plant photography as “mostly luck in being at the right place at the right time.” But waiting is also part of it: “watching a plant in bud, then repeated visits till the flowers are open, or the fruit is ripe and splitting, or a bird or insect is eating it. Getting moods, if possible, by waiting for the right light, or arriving when you think the light is right.” “Using flash helps to fill in the detail when things aren't as you want them,” he adds. “Digital format has revolutionized the idea of images for me because of quickness, and Photoshop can do wonders for a pic if you didn’t quite get it right. My only dismay is that some of my most evocative shots were done before the resolution of the CCD [charge-coupled devices] of digital cameras was what it is today. Even though I have retaken some images, they are not the same.” Generous sponsorship enables the Flora Publications Trust to make this book affordable and accessible to all. The next in the series will be on grasslands. “The challenge of this project,” Pooley says, “is to provide a fair introduction to plants across South Africa. There is such diversity within each biome.” This series will be well worth collecting and putting to regular use. ■
Peter Martinez describes the indispensable role of space technology in daily life.
services to people on Earth. The word ‘satellite’, derived from the Latin word satelles, means a servant or attendant. It’s a particularly appropriate term, since most of the satellites in Earth’s orbit serve humankind. They support sustainable development and underpin planning and decision-making with up-to-date and comprehensive geospatial information that powerfully complements measurements obtained on the ground. Satellites also help people to communicate with each other and to share information. Different kinds of satellite are used for different things. ■ Communications satellites. We use these for communications from one point on the Earth to another and for broadcast services to large areas on the ground. You’re
probably benefiting from one of these satellites when you make an international telephone call, surf the Internet, or watch a television news or sports programme. These satellites also deliver tele-medicine and tele-education services to remote regions. ■ Earth observation satellites. With their help we study the Earth for widely varying applications, such as environmental monitoring, urban planning, mapping, disaster management, and weather prediction. Every time you see a television or Internet weather forecast, you’re ▲ ▲
hy should we care about space? What does space do for people on the ground? Responding to some of the answers to these questions, Cabinet approved the establishment of a South African Space Agency on 26 July 2006. For the most part, the word ‘space’ conjures up images of the Universe ‘out there’ – the Hubble Space Telescope, robotic rovers on Mars, or astronauts and the International Space Station. These high-profile activities certainly speak to the basic human urge to explore the unknown, but ‘space’ has in fact become a global utility worth billions of rands each year. Often without realizing it, we all rely on space technology to go about our daily business, and most satellites are launched into space to provide
Above: Most satellites in space serve the needs of people on the ground. The European Space Agency’s Envisat (pictured here) addresses wide-ranging scientific questions about Earth’s processes and generates information that supports policy and decision making.
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receiving data that comes from an Earth observation satellite. ■ Navigation satellites. These determine precise positions in space and time. The spatial information they provide is used for navigation on land, sea, and air, and for tracking hazardous shipments. The temporal information is used wherever we need precision time-keeping. When you make a cellphone call, or use a bank ATM or a GPS receiver, you’re taking advantage of what navigation satellites offer. They also help experts to investigate the properties of the atmosphere. ■ Scientific satellites. These satellites allow researchers to study nearEarth space and to explore the Solar System and the distant Universe.
Satellites monitoring the Sun give advance warning of approaching space-weather events (called geomagnetic storms or substorms), which can damage other commercially important satellites and interfere with communications on Earth. These warnings allow airlines to divert flights on polar routes for reasons of communication or navigation, and also to reduce exposure by passengers and crew to increased radiation levels. Spacecraft have flown past seven other planets in our Solar System, giving fly-by glimpses of more than 60 moons and other celestial bodies. A few have even landed – on the Earth’s Moon, the planets Mars and Venus, the giant moon of Saturn called Titan, and the asteroid Eros. Remarkable voyages of discovery such as these are
providing far-reaching insights into the origin and evolution of our own Earth. Orbiting astronomical satellites offer views of the distant Universe at wavelengths not visible from the ground. When you see a breathtaking photograph of the surface of another planet or an image of the oldest and most distant galaxies in the Universe, you’re marvelling at results from a scientific satellite. So, to answer the core questions – we care about space because it has practical value … and also because it tells us extraordinary things about the Universe of which we are a part. ■ Dr Martinez is the Coordinator of the National Working Group on Space Science and Technology. For more information visit the South African Space Portal at www.space.gov.za.
Satellites of our own Bob Scholes, Arnold Schoonwinkel, and Hendrik Burger introduce the soon-to-be-launched South African-built Sumbandila satellite and the country’s future space plans.
n April 2007, South Africa’s low Earth orbiting microsatellite, SumbandilaSat, is scheduled to be launched into space from a Russian submarine near Murmansk on the Barents Sea. It’s the first of a series of national satellite developments that will give South Africa more affordable access to space technology and data. The country’s work on satellites is relatively new, but it’s been marked Above: A computer aided design (CAD) image of Sumbandila, the pathfinder satellite scheduled for launching in December 2006. Image: Courtesy of SunSpace
by unusual success. On 23 February 1999, a NASA rocket carried into orbit a University of Stellenbosch microsatellite called SunSat. One of only a handful of satellites ever launched that were designed and built by university students, this brave pioneer survived in the harsh space environment for nearly two years, beaming back images of the Earth’s surface and testing several innovative aerospace technologies. Its launch made South Africa one of a small group of nations with the capacity to build and operate space platforms. Why a space programme for a developing country? Let’s face it: the ‘space race’ has its origins in national pride. But beyond nation building, space programmes have strategic value and industrial spin-offs. Space is the ‘high ground’ of the 21st century. China, India, and Brazil
Satellites come in different sizes Broadly accepted convention classifies satellites as follows: ■ >500 kg: satellite – this type includes most communication, weather, and Earth observation satellites ■ 10–500 kg: microsatellite – includes many of the research satellites in space ■ 1–10 kg: nanosatellite – currently under development ■ >1 kg: picosatellite – none as yet, other than space junk! In practice, launch opportunities are defined as much by the volume occupied by the satellite as by its mass. The SumbandilaSat must fit into a box with dimensions 600 × 600 × 800 mm. The solar panels and the telescope baffles unfold once the satellite is safely in orbit in space.
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– all with active space programmes – together with South Africa, belong to a small group of developing nations seeking to master the technologies they need to leapfrog from lowvalue farming-and-mining economies to sophisticated service-andmanufacturing ones that offer higher growth rates and better quality jobs. Two African countries (Algeria and Nigeria) have recently purchased satellites from the developed world – we believe that building our own grows our capacity far more effectively. The task of designing and constructing satellites, as well as the data-processing software and supporting ground stations, raises standards of technology and manufacturing. It needs advanced capacity in materials science, electromechanical design, communications, optics, data-handling, precision manufacture, and testing and systems engineering. These hightech developments have applications in many spheres. South Africa has already notched up significant sales in the competitive domain of spacerelated hardware, and has created a small but competent industrial sector. Most important, a space programme develops, retains, and attracts skilled and talented people for the country1.
1. SunSat was the basis of over 100 master’s and doctoral degrees, and more than 50 people have developed new skills by working on the Multi-Sensor Microsatellite Imager instrument package.
So u t h Afric a int o s pa ce
South Africa’s history in space 1820 The Observatory in Cape Town was founded. As South Africa’s first scientific institution, it launched the country’s proud record in astronomy. 1960s NASA chose Hartebeesthoek, near Pretoria, as a site for tracking space vehicles in its Apollo programme. Thus began the country’s involvement with satellites. The facility became the CSIR Satellite Applications Centre, dedicated to receiving, processing, archiving, and disseminating images of the Earth, and tracking and controlling satellites in orbit. 1980s The increasingly-isolated South African government began a military space effort. Early 1990s The satellite and rocket development programme was terminated when, with political changes in South Africa, the perceived military threat receded. The country’s satellite-design capacity was initially redirected towards an environmentobservation satellite called GreenSat, which came to nothing. 1991–1999 Led by Garth Milne, Arnold Schoonwinkel, Jan du Plessis, and Sias Mostert, engineering students at the University of Stellenbosch designed and built a microsatellite as a collective project. Microsatellites are quicker to design, cheaper to build and launch, and more agile in space than ‘conventional’ satellites that weigh several tonnes. ‘SunSat’ was built – on a shoestring budget – in the Electronic Systems Laboratory of the Department of Electrical and Electronic Engineering, with optics designed and manufactured by the CSIR. SunSat used off-the-shelf electronic components where possible rather than the expensive custommade, ‘space-certified’ hardware typical of the big space agencies; NASA carried SunSat into orbit, piggy-back with a satellite of its own.
2001 To maintain the momentum, the University of Stellenbosch created a company called SunSpace to design and manufacture aerospace components. It has supplied international clients with satellite components, such as optics, sensors and starfinders, and a complete microsatellite. 2003 The Multi-Sensor Microsatellite Imager (MSMI) consortium was formed to build a radical new imager package for future microsatellites*. 2006 The South African Cabinet approved a programme of Earth Observation satellites – the ZASat series – for launches beginning in 2006. ‘ZA’ is the international designation for South Africa, based on the old Dutch name ‘Zuid-Afrika’. ZASat-002 (the second South African satellite after SunSat) is a smaller, lighter technology demonstrator (called a ‘pathfinder’ in space jargon), in preparation for ZASat-003, which will follow about a year later carrying the full MSMI package. Both launches will take place, on a commercial basis, from a Russian submarine in the Arctic. Once operational in space, satellites are normally given a new name. South African schoolchildren were invited to suggest a name for ZASat-002. The winner was ‘Sumbandila’, meaning ‘lead the way’ in the Venda language. * The consortium consisted of the University of Stellenbosch, SunSpace, the CSIR, and the Agricultural Research Council. The South African elements were funded by the Department of Science and Technology’s Innovation Fund. The consortium was joined by researchers from the Catholic University of Leuven and the private company called OIP (both from Belgium), whose contribution is funded from a Flemish government grant.
Left: The assembled SunSat (ZASat-001) on its handling trolley, prior to launch. Image: A. Schoonwinkel
Above right: A computer-aided design image of the ZASat-003 satellite, carrying the full MSMI sensor package. Image: Sunspace
of land surface. By measuring the precise absorption bands of particular molecules, hyperspectral sensors can provide information about crop health, nitrogen content, soil type, and mineral resources. Weed control is another example of the usefulness of MSMI sensors. South Africa’s government spends hundreds of millions of rands each year combating water-consuming alien vegetation so as to increase the flow in our rivers2. If MSMI can direct this investment more precisely, the benefits will be greatly improved. A third example involves urban service delivery. Like most developing countries, South Africa is urbanizing rapidly. MSMI can help to map and classify informal settlements and help to direct services to where they are needed. ▲ ▲
Our satellites will provide great Earth observation benefits. The MultiSensor Microsatellite Imager (MSMI) package that they will carry (see Fact File) was designed to improve food security in Africa, but meeting the observation specifications for this challenging task can also achieve much, much more. African and donor nations spend over a billion rands a year on hunger alleviation. If MSMI can improve by just a few percent the reliability of information about who needs what food and when, the savings on loss of life and resource wastage will easily cover the cost of the satellite. Many other satellites already in space can (and do) help, but none has the unique combination of wavebands and image detail we need to monitor crop development in smallholder fields in Africa. As a scientific bonus, the full MSMI package to be carried on ZASat-003 will include a hyperspectral sensor that slices the visible and infrared spectrum into over 200 narrow bands, providing a unique ‘spectral signature’ for different types
Q Fact file
Above right: High-resolution panchromatic image of small farmers’ fields from space. Image: Frans van den Bergh
Below: The same scene classified into objects, using spatial information in the image. Image: Frans van den Bergh
2. For more on the Working for Water programme, see Brian van Wilgen’s article, “Crackdown on Invasive Aliens”, in Quest (2004), 1(1), pp. 5–10, and p. 29 in this issue.
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Left: An image from space, provided by the commercial Ikonos satellite, of the area around Skukuza in the Kruger National Park, provided by the commercial Ikonos satellite. It has similar ground resolution to Sumbandila and the MSMI. Image: Ikonos
to decide, first, what the satellite is for, and then to work out the design specifications for satisfying those needs. Select an orbit
Table 1 – The South African satellite platforms ZASat-001 (SunSat)
Launch date and place
23 Feb 1999 April/May 2007 Vandenberg Air Force Base, Barents Sea, Russia California, USA
2008 Barents Sea, Russia
Oblique eccentric 620–850 km
Polar 500 km
Polar 660 km
• 4 bands in the visible and near-infrared • 15 m GSD* • 52-km swathe**
• 6-band multispectral • 6.5 m GSD* • 40-km swathe**
• 6-band multispectral • Panchromatic pushbroom • Panchromatic ‘area’ • 200-band hyperspectral***
400 mm focal length 80 mm aperture
1.72 m focal length 280 mm aperture
* GSD (Ground Sampling Distance) gives the approximate minimum size of the objects that the satellite can ‘see’ on the ground. ** The ‘swathe’ is the width of the strip that can be seen by the satellite. *** The hyperspectral sensor was designed and built by the consortium members in Belgium.
Recipe for a satellite Decide what you need it for
Designing a satellite involves compromises: between mass, cost, reliability, and performance characteristics. Sometimes different applications have similar requirements in terms of the wavelengths in which they observe the size of the objects they need to be able to see, and the frequency with which they need to see them – but this isn’t normally the case. So it’s crucial Left: SunSat was carried into space by NASA, ‘piggyback’ on another payload. Here it is being bolted to the common ‘chassis’ that holds the satellites until separation. Photograph: A Schoonwinkel
‘Space’ begins about 100 km above the Earth. The higher the orbit, the more expensive it is to launch the satellite into it. But orbits lower than 1 000 km experience a small drag caused by the remnants of the atmosphere. Unless it carries ‘booster’ fuel, the satellite gradually slows down and drops out of orbit. The higher the orbit, the harder it is to see small objects on the Earth’s surface. Therefore Earth Observing Satellites typically occupy ‘Low Earth Orbits’ (LEO) some 500–900 km up, which means they make one complete circuit around the Earth about every 90 minutes. During this time, the Earth rotates beneath them (assuming that they are in a ‘polar’ orbit, which takes them more or less over the north and south poles), and they see a different part of the globe on their next pass. Depending on the width of the strip they see (the ‘swathe’), it can be days or months before they pass directly over the same scene again. This period is called the ‘revisit interval’. In practice, the revisit interval also takes into account the possibility that clouds will sometimes obscure the scene. Satellites that must remain above a particular spot on Earth have to occupy a special ‘geostationary’ orbit. This is an equatorial orbit (moving around the Earth above the equator rather than over its axis) at approximately 36 000 km above the ground. There’s only one such orbit, and it’s in high demand for telecommunications and weather satellites, so the ‘parking spaces’ in the geostationary orbit are strictly regulated. Select a sensor system
Features on the Earth’s surface vary in size and spectral reflectance or radiance (‘colour’3). Different kinds of sensor are needed to detect this returning electromagnetic radiation (see Table 1). The visible and near-infrared part of the spectrum can be covered using cheap, robust, and sensitive silicon chargecoupled devices (CCDs). The longer wavelengths need more exotic detectors. Most satellites do not form an
3. Strictly speaking, colour relates just to the small portion of the electromagnetic spectrum that is visible to people, that is, between 400 and 800 nm wavelength. But the principle of reflecting or emitting radiation in particular wavelengths extends above and below this range. For more, read Helmut Neumann’s article, “Views from Space: Earth Observation”, in Quest (2005), 2(2), pp. 30–31.
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image by taking a two-dimensional snapshot as a digital camera does. Instead, they use the forward motion of the satellite to probe along the scene using a one-dimensional array of sensors, rather like a scanner. The advantage of microsatellites is that they’re relatively easy to point side to side to see something that does not lie directly below the satellite path. The same inertial control system can be used to ‘nod’ the sensor along the path, so that it dwells on a scene for a longer time, thus capturing more light. This feature becomes important if you’re looking at tiny objects within a narrow wavelength band – with the hyperspectral sensor, for instance, you have just a few photons to work with! The type of sensor and the quality of the optics control the ‘resolution’ (that is, they determine the smallest detail detectable on the focal plane). The telescope focusing on the image, together with the altitude of the orbit, then determines how big an object this proves to be when translated into its size on the ground (this measure is called the ‘ground sampling distance’). The swathe width is determined by the number of sensors you can pack across the focal plane. To reveal small objects on the ground, the swathe needs to be narrow. Fit the package together
The sensors, the optics, and the systems for control, navigation, data storage, communication, and power supply all need to work seamlessly together – and to fit into the microsatellite mass and volume restrictions. They have to work flawlessly, despite the violent shaking of the launch and the hostile environment of space. So they need a rigid ‘chassis’ made of light, strong materials and lots of careful design and testing. The prototypes begin as threedimensional drawings and computer models. Then physical models are built, to exacting standards, with the correct mass and shape. The components are baked, irradiated, and shaken to the point of failure – first individually, then together – and redesigned if necessary. Then an exact duplicate of the satellite is built and exposed to rigorous tests that mimic launch and space conditions. Once it passes all the tests, the actual satellite is built and packaged for shipping to the launch site. Design and build the ground sector
A satellite in space is no use if you can’t communicate with it or use its data, so a ‘ground sector’ must be built. The elements that stay behind on Earth – the antennas, control systems, data-
Table 2 – The full Multi-Sensor Microsatellite Imager instrument package The full package will be carried on ZASat-003. ZASat-002 (Sumbandila) will only carry a multispectral sensor. Attribute
Spectral bands (nm)
BLU XAN GRN RED REI NIR
400–2 350 (200 bands, each 10-nm wide)
440–510 520–540 520–590 620–680 690–730 840–890
Ground Sampling Distance (m)
Revisit period at equator (days)
With pointing 15º off-nadir
About 8 days, assuming no cloud cover
Right: A simulation of the various swathes created by the four sensors in the MSMI package that are to be carried on board the ZASat-003. Image: SunSpace Below right: A test model of parts of the MSMI telescope, which will be carried by the ZASat-003. The black carbon-fibre tube (left) supports the secondary mirror and the silver disk beneath represents the primary mirror. The gold sections are part of the hyperspectral assembly. The model is on the vibration table, where it is shaken as if undergoing a launch. Photograph: A. Schoonwinkel
processing hardware and software, image delivery systems, and applications developed for the data – are typically as expensive to build as the space hardware itself. (Fortunately, South Africa has many elements in place already, for instance in the CSIR’s Satellite Applications Centre.) The task also includes raising user awareness, training new operators, and preparing everyone for the deluge of information when it comes. Most satellites are designed to survive for only about five years in space, so once they’re successfully launched there’s no time to waste! The sky’s the limit In addition to the South African Space Agency (SASA), formed in July 2006, we also have a Space Council to decide on space policy. Next year South Africa chairs the prestigious international Committee of Earth Observation Satellites (CEOS) and joins the exclusive club of nations operating their own satellites. This small beginning will inspire many young people to dream of the stars – we hope it’ll help the work of those back home on the farm as well. ■ Dr Bob Scholes is a systems ecologist at the CSIR, Professor Arnold Schoonwinkel is Dean of Engineering at the University of Stellenbosch, and Hendrik Burger is project engineer at SunSpace Ltd.
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“For its part, the government is determined to increase the resource allocation for Research and Development and Innovation, and increase the pool of young President Thabo Mbeki, State of the Nation Address, 3 February 2006 researchers.”
The role of science and technology is so pervasive in all aspects of life that it is hard to imagine a modern government without an advisory body to which it can turn for advice on such matters. This is the role that NACI (the National Advisory Council on Innovation) fulfils in South Africa today. NACI was established in 1998 in terms the National Council on Innovation Act (Act No. 55 of 1997).
What is innovation? As a general concept, the word innovation is misleadingly familiar. But it has a specific technical meaning that is largely unrecognised. In the context of NACI, innovation can be described as follows:
Theoretical conception The conception of new ideas
+ Technical invention
The process of converting intellectual thought into a tangible, relevant object
+ Commercial exploitation
Converting inventions into products and/or services that will improve performance, have economic value, create wealth and improve quality of life
= InnovaTIon Innovation is thus not a single action but rather a series of interrelated subsidiary processes. It includes the conception of a new idea and the invention of a new device, approach or process for the market. It is important to recognise that innovation is not limited to the fields of science, engineering and technology. Often, the key to successful innovation lies in the social and human elements. It is therefore
fitting that NACI should also concern itself with human capital and the social challenges that the national system of innovation faces.
Issues, advice and studies Evidence-based policy research underpins NACI’s policy advice. Research is therefore not an end in itself. Accordingly, policy advice is much more than a summary of research findings and/or a synthesis of policy recommendations generated through empirical research. NACI currently has a portfolio of 16 studies at various stages, including: • Cabinet-requested study on tracking R&D Expenditure: Outputs, Outcome and Impacts. As part of this study, a successful workshop was held in April 2006 on the current state of knowledge in respect of the measurement of R&D and innovation, and their relationship to other economic variables. The presentations of the five international experts will be available on the NACI website (www.naci.org.za). • Physical infrastructure for Optimal Performance of the National System of Innovation. • Provincial Science and Innovation Systems in South Africa. This study will generate a map of innovation hotspots. The South African system of innovation tends to be concentrated in Gauteng and the Western Cape. The study will show the strengths and weaknesses of the provinces and generate a potential structure for functional decentralisation. • Development of a Model of Appropriate Human Resources for a Productive National System of Innovation • State of Ethics in the National System of Innovation, in the wake of the identification by the Truth and Reconciliation Commission of ethical and moral misconduct during the previous dispensation.
• OECD (Organisation for Economic Cooperation and Development) Evaluation of the Nature and Performance of the National System of Innovation. All NACI research reports are peer-reviewed by South African and overseas experts. NACI regularly briefs the Parliamentary Portfolio Committee on Science and Technology on its annual report of the previous year and its corporate business plan for the forthcoming year.
Future public activities Public workshops are being planned on the following topics: • The Importance of Biotechnology in a Development Context • Methodology of Evidence-based Policy Development • Science Systems for Development.
NACI National Advisory Committees Science, Engineering and Technology for Women (SET4W) In 2003, Cabinet established the South African Reference Group on Women in Science and Technology (now known as SET4W) as an advisory committee of NACI with Luci Abrahams as chair. On the basis of five completed studies, a policy on gender equity in the science system has been drafted and is currently being discussed. The first term of office of the committee has reached an end, and SET4W has been reconstituted as a national advisory committee of NACI. National Indicators Reference Group During 2005, the National Indicators Reference Group was established, with Dr John Stewart as chair, to provide NACI oversight of studies
on science and technology indicators and to ensure quality in such studies. The committee includes the Statistician-General among its members. National Biotechnology Advisory Committee The National Biotechnology Advisory Committee is being established to advise the government on the National Biotechnology Strategy with respect to promoting biotechnology and monitoring progress, determining funding priorities (especially for the Biotechnology Regional Innovation Centres), seeking cohesion and coherence among biotechnology practitioners, and ensuring an appropriate regulatory environment.
Dr Phil Mjwara took over the reins from Dr Rob Adam as Director-General of Science and Technology on 1 April 2006. As such, he serves as chief executive officer of NACI.
The secretariat comprises an executive director, three specialist managers – one each for science indicators, for policy research and for policy analysis and advice – and three administrative support staff.
Photographed at the first meeting of the Second Council were:
Strategic themes NACI has identified the following themes on which to focus in the medium term: • Infrastructure for innovation promotion • Human capital and the knowledge base • Science, technology and innovation for competitiveness • Social dimensions of innovation • Position and role of NACI in the national system of innovation. Gender, racial equity, poverty and development are cross-cutting themes.
NACI website Copies of South Africa’s major science, technology and innovation policy and strategy documents will soon be available on the NACI website (www.naci.org.za).
Back from left – Mr Fairoz Jaffer, Prof. Tshilidzi Marwala, Dr John Stewart, Mr Geoff Rothschild, Mr Alan Hirsch, Prof. Jennifer Thomson, Dr Steve Lennon, Dr Johannes Potgieter, Dr Francis Petersen, Mr John Marriott. Seated – Prof. Cheryl de la Rey, Dr Nombasa Tsengwa, Dr Ntuthuko Bhengu, Ms Luci Abrahams, Prof. Calie Pistorius, Dr Sibusiso Sibisi, Dr Rob Adam. The Councillors who could not be present for the photograph are:
NACI links NACI maintains sound working relationships with its counterparts abroad in countries such as Japan and the Netherlands, as well as with science policy institutions in Germany, the United Kingdom, the United States and African counties. NACI also forges links with its sister organisations in South Africa.
From left – Dr Khotso Mokhele, Dr Nhlanhla Msomi, Mr Thero Setiloane, Dr Mala Singh, Dr Nthoana Tau-Mzamane.
Challenges NACI’s main challenge is to deliver on its primary mission – providing advice to the Minister of Science and Technology on issues relating to the national system of innovation. In order for NACI to provide such advice, it must be able to develop informed opinions and translate them into a useful format. Ultimately, the performance of NACI will be judged against the quality of advice that it provides to the Minister.
For further information, consult the NACI website: www.naci.org.za.
Contact details: Private Bag X894, Pretoria 0001. Tel: +27 (0)12 843 6511 Fax: 086 681 0144
Excellence in the Science and Application of Engineering for All The South African Academy of Engineering (SAAE) has evolved into an organization that is now recognized by Government as worthy of being transformed into a statutory body. This major step forward will ensure that the SAAE takes its rightful place in society. Like its sister organizations in the developed and developing world, the SAAE is structured to render services at a strategic national level. Its fellows are experts in a wide range of engineering disciplines. The Academy’s vision is to be:
The preferred source of expert advice on matters pertaining to global competitiveness and quality of life for the nation. The SAAE harnesses its human resources to provide signiﬁcant support for decision-making processes in the private and public sectors. The following key strategic issues are currently under consideration: ◗ The establishment of a national transport infrastructure ◗ The energy debate ◗ A Marshall plan for technological human resources ◗ Poverty alleviation ◗ Manufacturing ◗ Sustainable development. In all these areas, the Academy of Engineering is able to assist by being an effective sounding board and provider of quality inputs.
For more information visit www.saae.co.za
Can e-language-support really help? Computer-assisted learning has offered hope to high school and tertiary-level students wanting to improve their communication skills. But not all programs seem to work. Can computers really do the job? Beth Jeffery and Jano Jonker explain their approach.
s teachers in tertiary education in the fields of English and physics – in a higher education institution originally designated for black students – we found ourselves working with large classes of people in a variety of disciplines, whose language communication skills needed urgent attention. Conditions were difficult. Lectures were packed with 150 or more students at a time (each individual having different needs and abilities). Many were financially strapped. Some science students had never used a computer and wouldn’t have a chance to begin until they’d been at university for six months. When they started, they were taught how to use a word processor, but, we realized, they weren’t learning how to write using a word processor: ‘information literacy’ is a different skill from ‘information technology’. What could we do to make a real difference? The late 1990s coincided with the growth of the web browser. The idea of creating a language-support software Information literacy and word processors
The beginning We could see what we wanted to do, but not, at first, how to do it. There was no prospect of leave, no secretary in the department, no funding for software development, and heavy teaching loads. But it could be done, we decided – and in the end it was, in our own time, nights and weekends, over the space of nearly a year. The result was the first version of the program we called ‘e4e’ (which stands for ‘English for Everyone’). Shaping a user-friendly web For the program to be as easy to use as possible, we based the web structure on three parameters: the students’ language needs, the logic of guiding users through paths to goals, and the progressive opening up of levels of explanation for users wanting more than the simplest answers. We focused on logic, hierarchy, and structure, and on what questions to ask when deciding where to link what. In a large-scale language support program, users make ‘free’ choices. But these choices mustn’t end in frustrating culs-de-sac – they have to yield useful answers to personal language problems, along routes that lead to success. The different tasks or goals of the program must be defined by the writing and learning needs of departments or professions. Richard Dawkins and Susan Blakemore1 had persuaded us to view language and culture as evolutionary systems, just as other natural systems are. So we created paths through different levels of explanation to suit each user’s needs. We drew on the work of M.A.K. Halliday, who first developed fully the evolutionary or functional approach to language. He borrowed the mathematical term ‘exponence’ to
1. The last chapter of Richard Dawkins’s book, The Selfish Gene (Oxford, Oxford University Press, 1976), discusses the evolution of culture, and there’s more background on language evolution in Susan Blakemore’s The Meme Machine (Oxford, Oxford University Press, 1999).
describe how each language category can be ‘explained’ – not with words and descriptions and definitions, but through the ‘list of contents’ belonging in each category or class. We applied this sort of thinking to language tasks: writing a report = performing all the actions or steps needed to complete it to a professional standard using a word processor. These included saving, inserting material, editing, layout, presentation, backing up, printing – that is, all the aspects of what makes up ‘good English’ in practice, not just grammar and syntax. It’s a practical approach, directed at creating specific products. Crucially, it avoids teaching ‘language’ or ‘English’ out of context. The underlying structure of e4e is complex, but the user interface needed to be experienced as intuitive. Students had to be able to navigate freely, to go back to their starting point, or choose new routes, or move to deeper levels of explanation if they wanted to; they also had to be able to click in, find an answer for an editing problem, and click out again. We had to escape from book mode (which is essentially linear: a heterogeneous list of ‘things to do’ on the way to mastering the goal of ‘good English’) into ‘webby’ mode, to give opportunities for holistic understanding (to those who wanted it). We came up with a program designed to adapt to the needs of many and varied users. The Internet browser made it accessible to anyone who knew how to click. Because it’s a web, it has no beginning or end. ▲ ▲
■ ‘Good English’ means ‘good information literacy’, whose three components are information retrieval, information management, and information reproduction. ■ Good information literacy comes from editing that’s structured and systemic. In ‘systemic’ editing, each language ‘system’ is checked in turn and improved as necessary – from spelling through format and layout, headings, numbering, plagiarism, and other things. Word processors are designed to facilitate writing. But spell checkers and grammar checkers aren’t intelligent and users need other ways to check the checkers. They might also need help with formats, paragraphs, linking words, headings, numbering methods, planning, and writing introductions and conclusions and abstracts. In addition, some people want more than rules; they want reasons. Language-support software supplements the word processor.
program appeared to us whole, one day in 1998, like a vision. Here was a way to address our students’ information literacy needs – to help them to learn and to succeed in the job market. It just needed the right kind of planning … and hard work to make it real!
What is ‘correct’ language support? It’s difficult to produce quantitative evidence to show that any specific technique or ‘intervention’ to help people with writing and communication actually works better than any other. That’s because assessment is subjective, and high pass rates in language classes don’t always transfer across to good marks in science or business courses – one reason being that teachers and lecturers in different subjects define the benchmark for ‘good English’ differently. The right kind of software can contribute to good writing because it doesn’t teach rules or insist on particular approaches. Instead, it provides a lasting battery of tools, resources, and methods.
Quest 3(1) 2006 41
Online support solves problems Here are some problems that online language support can solve. ■ Science students see traditional communication courses as ‘soft’ learning that’s often boring. ■ Different disciplines have different needs, and traditional communication courses aren’t always flexible enough to accommodate them all. ■ Students have different language backgrounds and different levels of preparedness and motivation, which online programs can more easily address. ■ Traditional teaching about language (grammar, syntax, communication theory) doesn’t actively teach people how to write well in practice. ■ Workplace writing is about word processing. ■ Good writing involves more than grammar and syntax rules; it involves retrieving information, thinking, planning, layout, saving, printing. ■ Students don’t know how to avoid plagiarism and many lecturers don’t know how to detect it nor do they have time to teach ways to avoid it. Online support can give guidelines, while students write, on how to avoid plagiarism. ■ Language specialists don’t want to teach remedial language courses, and specialists in other disciplines don’t want to deal with language problems. Software offers backup support to everyone.
What a good language-support program can and can’t do It can ■ help users to write ‘good English’ by applying good information literacy and by editing as they write ■ show students how to use resources and where to find answers ■ integrate writing with layout and word processing ■ satisfy different needs in different ways, with users working at their own pace. It can’t ■ save marking time in subjects such as English – though it can help if teachers highlight problem areas and if, after that, students use support software to improve and edit their writing ■ mechanize the teaching of language – ‘getting right answers to self-testing exercises’ helps a bit, but not a lot, because professional writing is a holistic process. ▲
What use is e4e? Language support is a contested field, and we wanted our program to be adaptable to divergent needs and ideologies. It had to be flexible enough for use in labs or writing centres or lectures, or by individuals working alone, or in any combination of those modes. To be good enough, our program had to stand outside the fray – all things to all users. Focus on performance. Functional linguists assess specific performances rather than abstractions such as language ‘competence’. Teaching grammar hasn’t been shown to help students to write better in practice, so we tried, instead,
42 Quest 3(1) 2006
Above: In principle, all the paths to goals can be visualized as moving through the language web from core needs in the centre shared by all users of language, no matter what their discipline, towards performance goals in different fields on the periphery.
to improve performance by helping our users edit grammar while they were actually carrying out academic or profession assignments (such as writing a newsletter or a report). As students worked, they could use the program to discover, for themselves, the answers they needed for solving the language problems they were grappling with during the process of writing. Constant support. To provide constant support, the program breaks down information literacy into its constituent parts – information retrieval, information management, and information reproduction. Each of these three parts breaks down into further components. Reading and reading strategies, for example, are part Save trees – edit online! Worried about wasting paper? Or about the cost of printing rough drafts? Take the paperless route! Students can practise professional editing by submitting drafts online in a shared class-folder (on the intranet). The lecturer highlights points that need editing – which is much quicker than marking. Students re-access their documents, then use support software to edit the highlighted sections. After that they resubmit. In this way students: ■ have to draft and edit online (they never liked red ink corrections anyway!) ■ avoid wasting time, paper, or money on printing ■ produce better-quality work ■ learn to make backups.
of information retrieval. Users can follow step-by-step processes towards goals in specific writing outputs such as reports, projects, newsletters, summaries, or reading and note-taking. They can also use the program for instant answers to specific points. Multi disciplinary. En route to their goals, all learners in all disciplines use the same core characteristics of formal English no matter what the subject or content. They all need to acquire editing skills, to avoid plagiarism, and to apply time-management. They all need to read; insert and make tables, graphs, and charts; find websites; conduct keyword searches; write references; quote the work of others … and much more. All students and professional workers in South Africa can read, write, and speak English. But writing for professional purposes is a skill that has to be learned – by everyone, be they first- or second-language speakers. The proof of the workability of the e4e program and of the way we had designed it, however, was not in the theory but in the practical application. Would anyone want to use it? We discovered, to our delight and satisfaction, that e4e has been applied for nearly a decade in various institutions in South Africa and abroad. Students who are not computer literate in February can become competent in the program by March. It has been used in every subject by foundation students (that is, students without matric entrance
Q Viewpoint requirements); by undergraduates in communication courses; by science students; by students in English up to honours level; and by first and second language learners. In 2002 and 2003, foundation students made newsletters professional enough to print and sell in support of the charity of their choice. Now we’re working on a new, improved version! Can computer-assisted languagesupport work? We think it can. ■ Dr Beth Jeffery was in the Department of English and Jano Jonker is in the Department of Physics at the Nelson Mandela Metropolitan University.
For more on everything about language, consult D. Crystal, The Cambridge Encyclopedia of Language (Cambridge, Cambridge University Press, 1997). For functional approaches to language, read M.A.K. Halliday and J.R. Martin, Writing Science: Literacy and discursive power (London, The Falmer Press, 1996) and T. Hutchinson and A. Waters, English for Specific Purposes: A learning-centred approach (Cambridge, Cambridge University Press, 1987). Useful South African textbooks include M.H. Orr et al., A Practical Guide to Reading, Writing and Thinking Skills (Johannesburg, Southern Book Publishers, 1995); M.H. Orr and C.J.H. Schutte, The Language of Science (Durban, Butterworths, 1992); and P. Kotecha and A. du Plessis, Communication for Engineers (Cape Town, Maskew Miller Longman, 1994). For language support on the web, try Purdue University Online Writing Lab at http://owl.english. purdue.edu/ (but websites provide slow access and can’t be used as constant background support).
The language-support software program e4e is designed to support students when they write and is suitable for academic and professional writers from high school through tertiary level and in the workplace. For details visit www.e4e.co.za or email email@example.com.
If you enjoy scientific tourism, you’ll find there’s more to Grahamstown than a pretty Eastern Cape centre with a big university. Cindy Fisher and Nomtha Myoli describe some of the options.
Q The S&T Tourist
E xplore science in G raham stown Grahamstown is perfect for visitors wanting more than just beaches and golf estates (though you’ll find these, too, within a half an hour’s drive from the city). Known for its annual arts festival, it also offers much to engage people with scientific interests. The Eastern Cape has an unpredictable, variable climate and the Grahamstown area is officially semi-arid to sub-humid with temperatures ranging from 6 °C in winter to 25 °C in summer. Varied, too, is the surrounding scenery – unspoilt, spectacular, and among the country’s most ecologically diverse. Major South African biomes (apart from desert) are represented within a 150-km1 radius, and about 420 000 hectares are devoted to nature and game conservation. The Great Fish River Reserve, for instance, is an exceptionally fine example of succulent valley bushveld. In town you’ll find the Makana Botanical Gardens – the second botanical gardens to be established in the Cape Colony (in 1853) and originally laid out for the Lieutenant Governor commanding the British garrison residing in Grahamstown. They now provide sanctuary to common local as well as rare bird species. An animal of a different kind, the ‘living fossil’ coelacanth, is on view at the South African Institute for Aquatic Biodiversity, whose National Fish Collection is Africa’s largest collection of its kind. There are eight major game reserves within striking distance of town (including Shamwari, Bushman Sands, and the Addo Elephant National Park). Alternatively, you can view the ‘big five’ as stuffed animals in the safety of the Natural Science Museum (at a fraction of the price), where there’s also a hall of stuffed birds with information about the migration patterns of South African birds. Another must-do in Grahamstown is to look through the only genuine Victorian camera obscura in the southern hemisphere, on the top floor of the Observatory Museum. Built by the 19th-century watchmaker, Henry Galpin, it looks like a periscope, and through it you can see a rotating panorama of the town and its activities. Galpin
Above: Ancient Egyptian mummy at the Albany Natural Science Museum dating back to 1 425 years BC. The woman, whose name is not known, was buried with her cat, and is one of only four mummies in South Africa. The museum holds other valuables of Greek, Roman, and Egyptian origin and also has an impressive collection of aculeate wasps. Left: This theropod (or carnivorous dinosaur), Nqwebasaurus thwazi, is part also built the observatory, of the Eastern Cape fossil heritage housed meridian room, and science in the Albany Natural History Museum. room, and helped to identify The first dinosaur to be given a Xhosa South Africa’s very first name, it goes back to the Cretaceous diamond, the Eureka, which period. Photographs: Albany Museum marked the beginning of South Africa’s multimillion-rand diamond industry. On Gunfire Hill, the astronomical toposcope shows the cardinal points and positions for the risings of certain southern-hemisphere constellations. The 1820 Settlers National Monument nearby accommodates the Grahamstown Foundation, home to the annual Sasol SciFest (see p. 47). It’s a popular year-round venue for all kinds of cultural, social, and educational events. ■ Cindy Fisher is a journalist for Die Burger newspaper and is based in the Eastern Cape. Nomtha Myoli is Communications Officer at the South African Institute for Aquatic Biodiversity. For details, visit the Albany Museum website at www.ru.ac.za/affiliates/am; the Grahamstown Foundation at www.foundation.org.za; the Makana Botanical Gardens at www.bots.ru.ac.za; and the South African Institute for Aquatic Biodiversity at www.saiab. ru.ac.za. Contact the Grahamstown tourist office, Makana Tourism by phone on (046) 622 3241; fax (046) 622 3266; or e-mail firstname.lastname@example.org, or visit www.grahamstown.co.za.
1. The biomes include Cape fynbos, Nama-Karoo, thicket, savanna, grasslands, and Afromontane forest.
Quest 3(1) 2006 43
What is ‘quality’ furniture? ‘Quality’ is a term used in many different contexts, but what does it mean in practice? QUEST asked the Bakos brothers to explain the characteristics of ‘quality’ in furniture that people use every day.
udgets play a part in virtually every decision. If the country needs a new telescope, if a province needs to upgrade its public transport system, if a family needs to buy new furniture – the questions always include “what will it cost?” and “are we getting value for money?” The answers always involve ‘quality’, which can be difficult to define. To get back to basics to understand the term better, we asked Bernard, Norman, and Tyrone Bakos to sum up what we’re buying when we pay twice as much for one bed or sofa or desk as we do for another. Their answers are summarized here, as a guide to ‘quality furniture’ – and as an approach that could help define ‘quality anything’.
How do you define ‘quality’ furniture? The answer depends on the context. Start by knowing what you want: that will tell you what quality to look for. Are you the kind of person who enjoys a complete change every three or four years? Or do you want your new sofa to last at least 20 or 25 years? If you like what you see in the showroom and it doesn’t matter to you that the foam will start sagging or the frame will start distorting within three or four years, you might pay, say, R6 000 (at current prices). For a similar sofa with a lifetime at least four times as long, you should expect to pay in the region of R13 000. So it’s important to know what you’re buying. For some people it makes sense to pay twice as much for furniture that’s guaranteed to last four times longer. (If you get bored with the colour, a good-quality sofa is worth re-covering, which is cheaper than buying a new one.)
Furniture made from chipboard, for example, is cheaper than furniture made from solid wood, but compressed wood is more brittle, so it starts splintering or even breaking after a couple of years of use. When you build a wooden structure to last, you screw and bolt it as well as using glue; it’s cheaper just to use glue, but the furniture is far less sturdy.
What about comfort and aesthetics? Comfort has to do with what’s inside the furniture – what you don’t normally see! – and both comfort and aesthetics also have to do with design details. The traditional-style sofa in the picture, for example, has a sprung edge rather than a (far less expensive) hard edge. The sprung edge is particularly comfortable because it accommodates the shape of your bent knee while you sit. But constructing a sprung edge is specialist work, so you pay more for it. Comfort in a sofa also depends on the way the cushions are made. The crosssection (see picture) shows the design of a cushion constructed with pockets that are filled with a good-quality modern equivalent of duckdown mixed with foam chips. When you sit in it, the cushion will flatten. But when you rise, the cushion can easily be ‘plumped up’ back to its original shape. For aesthetics, there are design ‘tricks’ that people often don’t know about. We always suggest, for example, that the headboard of a bed be distinctly wider than the width of the bed itself. That way, the bedcovers and pillows on the bed lie within the area of the headboard, making for an elegant ‘look’. ■
What’s the difference between furniture that lasts and furniture that doesn’t?
The Bakos brothers have decades of experience in designing, making, and selling quality furniture in Johannesburg (in Dunkeld and Sandton).
It mainly has to do with the quality of the materials and the method of construction.
For more phone Bakos Brothers at (011) 325 2400 or (011) 783 9065 or visit www.bakosbrothers.com.
If you have questions about ‘quality’ furniture, e-mail them with the subject line “QUEST Questions” to email@example.com (or fax them to  673 3683) for answers in the next issue of QUEST.
44 Quest 3(1) 2006
Q Q uest crossword Youâ€™ll find most of the answers in our pages, so it helps to read the magazine before doing the puzzle.
Books create Success
1 Fishing method that can often catch fish and birds (5) 6 The first of its kind, or trial model (9) 7 Respiratory organs in a fish (5) 9 Spinning mass of water (4) 10 The branch of zoology that studies fishes (11) 14 Arachnid and Internet home base (3) 15 A measuring device (5) 17 Area about 500â€“900 km up where you find some spacecraft (3) 19 Type of steenbras (5) 20 Apparatus that hears objects under water (5) 23 Instrument that appears to bring distant objects closer (9) 25 The maximum number of years most satellites are designed to survive in space (4) 27 Small nectar-feeding bird (7) 28 Global system that uses the TCP/IP network protocols to facilitate data transmission and exchange (8)
1 Method used for following the travel patterns of a fish or bird (7) 2 Conveyance that is guided from a distance (3) 3 Type of map that shows the natural and artificial features of an area (11) 4 A fixed number of binary digits in a computer, often representing a single unit of data (4) 5 SumbandilaSat was named in which language? (5) 8 Part of the eye (6) 11 A bird of prey (4) 12 Natural home of an animal or plant (7) 13 The process of obtaining and transmitting measurements of data from remote sources, usually by radio (9) 16 A condition or state that can conserve energy in winter (6) 18 Extraterrestrial informationgathering package (4) 21 An outcrop of rock, sand, or coral near the surface of the sea (4) 22 Device to detect, record, or measure a physical property (6) 24 Spacecraft trajectory (5) 25 Thin, flat organs that fish use for steering (4) 26 Estuary managers use this (4)
How do you like the crossword puzzle? Was this one too difficult? Too easy? Just right? Would you like a more difficult puzzle as well (with a prize)? Fax The Editor at (011) 673 3683 or e-mail your comments to firstname.lastname@example.org (Mark your message CROSSWORD COMMENT.)
For all book, reference, subscriptions, library enquiries or orders call 021 918 8400 or e-mail email@example.com
Letters to Early South African birds
im Crowe (Quest vol.2 no.4) describes new data on ‘early birds’, which very likely originated from the Gondwana supercontinent more than 100 million years ago. It is encouraging to see molecular (DNA) and fossil data being used together. Of special interest is that South African fossils include archosaurs such as Euparkeria, which existed about 220 million years ago and which are likely to have been distant ancestors for birds and dinosaurs. Palaeontologist Johan Welman has even suggested that Euparkeria was feathered, but
without certainty. I have looked hard for impressions of feathers in the matrix associated with Euparkeria fossils from Aliwal North, but the sediments were probably too coarse (unlike the wonderfully fine sediments associated with the feathered Archaeopteryx from Germany). Remarkably, the cranium of the South African Euparkeria is similar in some respects to the crania of (younger) Chinese ‘feathered dinosaurs’. Our South African archosaurs deserve greater attention in research on avian origins. Francis Thackeray, Transvaal Museum, Pretoria
Why invest in big science?
s a fan of planetary and space science, I thoroughly enjoyed the article by Professor Phil Charles (Quest vol.2 no.2) on the Southern African Large Telescope (SALT). Certain things ‘dampen’ its image for me, however. As a third-world country, South Africa doesn’t have the money to spend on large-scale projects like this. It should have gone towards poverty alleviation, town/city upgrades, environmental schemes, disease research, job creation (especially with South Africa’s 40% unemployment), education, and the like, for the benefit of everyone. The telescope benefits only a select few who are interested in science! The money would have been better spent on educational institutions. South Africa has the night skies, but SALT should not come before saving lives, the environment, or our towns and cities. I am all for SALT – but perhaps we should get our priorities right. Adrian van der Velden, St Alban’s College, Pretoria
ALT gives South Africa’s astronomers a head start in the race for galactic knowledge. Do we truly need to be an astronomical power? Could the money not have been better spent? SALT gives scientific and industrial benefits. Our astronomers need to compete, but why pay to build the largest single optical telescope in the southern hemisphere and equal to the largest in the world? While SALT may claim to be “overcoming apartheid’s legacy” and “benefiting and developing education”, our problems are much greater than what is happening 200 000 light years away. We are not the USA, so, before competing about things that are meaningless in the context of life in our country and continent, let’s help people who are unemployed, starving, and homeless. Aren’t there better ways than SALT to improve education, thus overcoming apartheid’s main legacy? Why not spend on new schools, facilities, better teachers, or bursaries? Richard van der Byl, St Alban’s College, Pretoria
Phil Charles, Director of the South African Astronomical Observatory (SAAO), replies. Similar important questions have been raised since the SALT project began. It would be easy to take the money invested in SALT (and, next, the Karoo Array Telescope) and use it directly for poverty alleviation or (even more important) education. Identical demands could be made in many countries. If followed, they would preclude people there from participating in fundamental science until some unspecified time in the future when these problems had been ‘solved’. That, I believe, is counter-productive in the long term. In areas such as medicine and energy, South Africa contributes to fundamental research for its potentially direct benefits to the entire population. Economic limitations mean that the country cannot fund significant research in all scientific disciplines. Instead, it focuses where we have special strengths (such as our fossil heritage) or geographical advantages, such as the southern skies, the properties of the Earth's magnetic field, and remarkable biodiversity. A globe of the Earth (not a flat map) shows how little of our planet's land mass lies south of the equator, so studies of our skies (with unique access to the centre of our Milky Way galaxy and our nearest neighbouring galaxies,
46 Quest 3(1) 2005
the Magellanic Clouds) can be undertaken only from Chile, South Africa, and Australia (Antarctica is too expensive for all but a few niche areas). Australia lacks high-altitude locations, so only Chile and South Africa are suitable for world-class astronomical research in the southern hemisphere. This geographical advantage (receiving legislative protection through the Astronomical Geographic Advantage Protection bill currently before Parliament) gave South Africa its long history in astronomy. SALT was the natural next step. n SALT, constructed for only 20% of the cost of comparable telescopes elsewhere, was a remarkably cost-effective way of joining the “10-m club“ of giant ground-based telescopes. n Only one-third of the cost of construction and operation accrued to South Africa, the rest was carried by international partners, who also contribute substantially to ‘collateral’ benefits (mostly in science education) for South Africa. n South African companies secured two-thirds (by cost) of the construction contracts. n SALT has developed direct science education programmes for schools in the region, reaching thousands of learners and providing key materials for teachers. n SALT exemplifies the new South Africa’s viable role in global-scale science at a cost it can afford, bringing substantial (potentially huge if SKA is sited in South Africa) external investment to local industries. Like research facilities across the sciences, SALT is used by a select few, but we expect many South African research students to train using SALT data. Also, astronomy engages with the general public, offering an inspirational mode of entry into understanding our Universe, and introducing fundamental concepts in science and mathematics. With South Africa’s appalling lack of suitably qualified, well-prepared science and maths teachers, it could take many years for us to see improvement in these subjects. I firmly believe that SALT is making a major difference. Twenty-five years ago, when I was involved in setting up the Anglo–Dutch– Spanish observatory on La Palma in the Canary Islands, Spain’s position was similar. In the immediate post-Franco era, it was coming to terms with over 30 years of significant isolation and under-investment in health and education. Spain exploited its geographical advantage in astronomy (the Canary Islands and the Sierra Nevada), as South Africa is now doing. It imported external effort for training and, in the past 20 years, the rising profile of astronomy has inspired young people into science careers (astronomical training provides superb fundamental experience in computing, systems and software development, numerical modelling, theoretical physics, and problem-solving). That is what South Africa is aiming for! At the SALT inauguration in November 2005, President Mbeki said: “This observatory is a place dedicated to the pursuit of knowledge. Its sole purpose is the discovery of the unknown, and therefore the further liberation of humanity from blind action informed by superstition that derives from failure to fathom the regularities and imperatives of the infinite natural world.“ His incredibly forward-looking speech* shows how far this country has come in a short time. It has further to go. We hope that international science projects such as SALT can contribute significantly to its future. * For the full text, visit www.saao.ac.za.
Q ASSAf News
Food on the table Small-scale, crop-based agriculture is overwhelmingly conducted in South Africa to supplement family or community food resources (subsistence) and income in rural and semi-urban areas. The farmers are capable of using scientific information and innovative practices if they see returns for investment of time and money. These insights were offered at the international workshop on “Science-based improvements of rural/subsistence agriculture” organized by the ASSAf Committee on Science for the Alleviation of Poverty. The meeting illustrated discoveries and projects to improve the productivity and quality of life of agrarian people. Among the highlights were the Bill and Melinda Gates Foundation’s grant of US$18.5 million for the Africa Biofortified Sorghum Project headed by Kenya’s Florence Wambugu. Scientific teams across Africa are trying to invent new strains of this indigenous staple (‘super sorghum’) that are more easily digestible, richer in key nutrients, and higheryielding, than strains currently used – 300 million people will benefit if the project succeeds. To counter threats from pathogens, Ed Rybicki’s group (University of Cape Town) has produced maize strains with high resistance to the maize streak virus, which is thought to affect 20% of South Africa’s total maize crop. Felix Dakora’s team (Cape Peninsula University of Technology) is examining the
Holiday specials ■ Iziko Planetarium, Cape Town Junior stargazers can join Sunshine Simon on his quest to find the ‘missing’ Sun. Teens and adults can journey to the Great Pyramid of Khufu (Egypt), whose elaborate system of shafts is directed towards the most prominent stars in the night sky (daily shows). “The Sky Tonight” runs weekends at 13:00. Phone (021) 481 3900 or visit www.iziko.org.za. ■ South African Astronomical Observatory (SAAO) For details of the SAAO tours in Observatory, Cape Town, visit www.saao.ac.za/public. For Day and Night tours to SAAO Sutherland (booking is essential), phone (023) 571 2436 or fax (023) 571 1413 or e-mail firstname.lastname@example.org. ■ MTN ScienCentre, Cape Town Visit “The Sultans of Science” exhibition of great Islamic inventions that laid the foundation for modern science in optics, physics, mechanics, flight, astronomy, cartography (17 November 2006– 15 February 2007). Join the holiday programme with over 300 ‘hands-on’ displays. For details phone (021) 529 8100 or visit www.mtnsciencentre.org.za. ■ Bayworld, Port Elizabeth For youngsters from 5–14 years there’s a great variety of supervised holiday activities including science, sport, pottery, photography, and many others. Contact Anche at (041) 584 0650 or e-mail email@example.com or call Tracy at 083 456 3292. ■ Old Mutual MTN ScienCentre, Umhlanga Action-packed holiday programme for young people of different ages (2 December 2006–14 January 2007) includes the Lego Robotics Workshop (explore distant planets), Electricity Workshop (make a circuit board),
role of nitrogen-fixing bacteria, located underground in root nodules, in producing further growth and vigour-promoting effects, even in non-legumes. Ian Robertson (University of Zimbabwe and Agri-Biotech Ltd) has used a ‘systems approach’ to help communities increase their yield of sweet potatoes from 4 tonnes per hectare to ten times that number. Virus-free vines are sold at low cost to small-scale farmers, who then apply basic knowledge of good practice in crop plant cultivation in soils that are considered ‘poor’. The workshop showed science actively helping in the daily struggle to put food on the table and to raise levels of income for needy families. – Wieland Gevers Once published, the workshop proceedings will be available from the Academy at www.assaf.org.za.
ASSAf awards 2006 On 27 October 2006, the two annual ASSAf Science-for-Society gold medals were awarded to Professor Walter (Wally) Marasas and Professor David Glasser for outstanding achievement in applying scientific thinking in the service of society. The renowned Professor Marasas (Medical Research Council) works on the mycotoxins produced by fungi that cause many serious human and animal diseases. His team’s research led to the discovery of the novel mycotoxin known worldwide as fumonisin and indicated Technofuture: Technomovie (create a roboticsthemed movie), Super Science Shows, and the ScienCentre Science Lab Shop for science and technology toys, games, and novelties. Booking essential for workshops. Phone (031) 566 8040 and visit www.gatewaysciencentre.co.za.
■ Maropeng, Cradle of Humankind, Gauteng Visit the special exhibition of fossils found at Gladysvale (October 2006–28 February 2007). Children will enjoy an underground boat-ride, digging for fossils, phoning a Dodo, and all the interactive exhibits. Phone (014) 577 9000 or visit www.maropeng.co.za.
Get close to nature ■ The Spider Club of Southern Africa Events and activities in and near Gauteng include the outing (25 November 2006) to the Cullinan Conservancy, Dinokeng (book via Ian Engelbrecht on 082 763 4596 or e-mail firstname.lastname@example.org) and others on 20 January 2007 (phone Carol Smith on 083 374 6116 or e-mail email@example.com) and 27 January 2007 (to the Maryvale Bird Sanctuary, near Nigel on the East Rand) (phone Danie Smit on 082 418 5869 or e-mail Danie.Smit@improchem.co.za). There are regular Spider Identification courses – all ages welcome (contact Ian Engelbrecht [details above] or contact Astri Leroy on (011) 958 0695 or e-mail firstname.lastname@example.org).
its likely link with oesophageal cancer in the Transkei, where the rate of occurrence of this disease is among the highest in the world. Professor David Glasser (University of the Witwatersrand) and his team have developed fundamental tools and methods in the discipline of chemical engineering, enabling them to design and analyse industrial chemical processes so as to improve them and make them cheaper, thus allowing feedstocks to be used more efficiently and to generate less pollution. The centre that Glasser founded has become the technology supplier for a major oil-from-coal plant in China as well as another in Australia. The Young Scientist Award of the Academy of Sciences for the Developing World went to biochemist Professor Debra Meyer (University of Johannesburg) for her work on HIV/AIDS. She is involved in vaccine development and is investigating ways to develop less toxic antiretroviral drugs.
New ASSAf Council The Academy’s new council comprises: Robin Crewe (President), Patricia Berjak and Jonathan Jansen (Vice Presidents), Benito Khotseng (General Secretary), Rob Adam, Vivian de Klerk, Manfred Hellberg, Sunil Maharaj, Chabani Manganyi, Daniel Ncayiyana, Francis Petersen, Priscilla Reddy, Peter Vale, and Jimmy Volmink.
Q Diary of events ■ Peace-of-Eden experiences Learn from the Wisdom of Elephants (8–10 December 2006 [book by 20 November]) and enrich your life as you Mingle with Wild Meerkats (2–5 February 2007 [book by 7 January]). For more on wildlife tour and teambuilding experiences contact psychotherapist and ecotherapist Mandy Young on (021) 531 1446, e-mail email@example.com, or visit www.peace-of-eden.co.za. ■ Jane Goodall Institute South Africa For more on their invaluable work with chimpanzees, and if you want to help, visit www.janegoodall.co.za.
Gatherings ■ Science-in-Society/Society-in-Science – African Forum, the first-ever African science communication conference: Port Elizabeth, 4–7 December. Visit www.saasta.ac.za/ascc. ■ Southern African Association of Science and Technology Centres (9th Annual Conference) – international forum covering the impact of science centres and offering models for our region: Unizul Science Centre, Richards Bay, 29 November–1 December. Visit the Unizul Science Centre at http://scictr.uzulu.ac.za. ■ NanoAfrica – interdisciplinary conference giving local industry and academia an insight into nanotechnology research in South Africa and other African countries: University of Cape Town, 26–29 November. More at www.sani.org.za. ■ Sasol SciFest – South Africa’s leading science festival: Grahamstown, 21–27 March 2007. For more phone (046) 603 1106 or visit www.scifest.org.za.
Quest 3(1) 2006 47
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48 Quest 3(1) 2006
Q Back page science Who are the scientists? ■ “Touch a scientist and you touch a child.” American writer Ray Bradbury (1920– ) ■
“Science is an integral part of culture. It’s not this foreign thing, done by an arcane priesthood. It’s one of the glories of the human intellectual tradition.” US scientist Stephen Jay Gould (1941–2002)
■ “Among scientists are collectors, classifiers, and compulsive tidiers-up; many are detectives by temperament and many are explorers; some are artists and others artisans.” Sir Peter Medawar (1915–1987) Go ahead, make me What makes an expert: talent or training? Philip E. Ross (Scientific American, August 2006) writes that a century of research into chess players – sometimes called “the Drosophila of cognitive science” because their skill can be measured and experimented on – has resulted in new theories about how we think and remember. In summary, it looks as if “experts are made, not born”. And a Harvard economist has had promising results experimenting with cash incentives for students to do better in school tests. Worms and insects ■ Earthworms in Europe are feeling the heat. Scientists are using mustard to force them to the surface, so as to monitor their populations as part of an experiment in improving the condition of farmlands. Fields with plenty of worm-burrows absorb water better, so they’re less likely to be damaged by floods and soil erosion. In 2002, a week of heavy rains caused catastrophic floods in Europe. More followed in 2005. The mustard is seen as a more environmentally friendly way to shift worms than chemicals or digging. Did anyone ask the worms? (The Guardian, 9 May 2006)
■ Other researchers have the interests of lowly creatures at heart. Hungarian scientists conducted an experiment to find out which colour of car was most likely to attract insects in wetlands. The insects mistake the shiny surface for water, and lay their eggs on it. That’s not a good survival tactic. Red or black cars, which reflect light in a polarized and horizontal way, as water does, were the most popular. So the researchers recommended visiting wetlands in lightcoloured cars – or, better still, dirty ones. (New York Times, 2 May 2006) This, too, shall pass ■ Breakthroughs change our world, but nothing lasts for ever. The pioneering geologist Charles Lyell (1797–1875) wrote about the traces that humans will leave: “[N]one of the works of a mortal can be eternal…. Even when they have been included in rocky strata, when they have been made to enter as it were into the solid framework of the globe itself, they must nevertheless eventually perish; for every year some portion of the earth’s crust is shattered by earthquakes or melted by volcanic fire, or ground to dust by the moving waters on the surface.” (The Faber Book of Science, Faber & Faber, 1995) ■ Sometimes discovery is the kiss of death. The English writer Edmund Gosse (1849–1928) told how his father Philip Gosse’s popular book on the marine life in British rockpools, The Aquarium (1854), had had disastrous consequences: “The ring of living beauty drawn about our shores was a very thin and fragile one. It had existed all those centuries solely in consequence of the indifference, the blissful ignorance of man. These rock-basins … thronged with beautiful, sensitive forms of life – they exist no longer…. An army of collectors has passed over them, and ravaged every corner of them…. the exquisite product of centuries of natural selection has been
crushed under the rough paw of wellmeaning, idle-minded curiosity.” ■ The English immunologist Sir Peter Medawar (1915–1987) noted: “Today the world changes so quickly that in growing up we take leave not just of youth but of the world we were young in.” Women who watched their figures Before calculators and computers, numbercrunching had to be done by people, in manageable chunks. “In the history of computing, the humbler levels of scientific work were open, even welcoming, to women,” writes David Skinner (The New Atlantis, No. 12, Spring 2006), reviewing David Alan Grier’s book When Computers Were Human (Princeton University Press, 2005). “Indeed, by the early twentieth century computing was thought of as women’s work and computers were assumed to be female.” Skinner points out that science “often had the benefit of highly talented and under-rewarded female minds who could not stake claim to better-paid academic positions”. After World War II, machines started taking over. “With the discovery of binary logic, the simplest parts of long problems became both too voluminous and too simple for human hands.” It calls to mind this quotation: “In a few minutes a computer can make a mistake so great that it would have taken many men many months to equal it.“ Anon. Answers to Crossword (page 45) ACROSS: 1 Trawl, 6 Prototype, 7 Gills, 9 Eddy, 10 Ichthyology, 14 Web, 15 Gauge, 17 LEO, 19 White, 20 Sonar, 23 Telescope, 25 Five, 27 Sunbird, 28 Internet. DOWN: 1 Tagging, 2 ROV, 3 Topographic, 4 Byte, 5 Venda, 8 Cornea, 11 Hawk, 12 Habitat, 13 Telemetry, 16 Torpor, 18 MSMI, 21 Reef, 22 Sensor, 24 Orbit, 25 Fins, 26 EFCI.
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Quest 3(1) 2006 49
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