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This is actively expressed in wide-ranging initiatives to make enduring, meaningful contributions to life below water, including our pioneering coral restoration programme in the Ocean Cay MSC Marine Reserve in The Bahamas.

It is similarly reflected in our recognition that humanity can only rise to the challenges facing our Blue Planet if we join together in our efforts.

This extends from collaborative research and knowledge-sharing to partnerships that bring public, private, academic, and civil society parties together, building synergies between them.

So, when our work brought us into contact with the Ba’a Foundation, which had already embarked on an equally committed path of pioneering coral conservation and restoration in the Red Sea, we jumped at the opportunity to join forces with a view to also helping move the needle for coral worldwide.

Combining scientific detail with a clear and accessible style, this booklet summarises the tremendous environmental, economic and societal importance of coral reefs, together with their biology and the threats they face today, from predators to pollution and global heating.

But at the same time, it also outlines the opportunities to halt and reverse the terrible damage coral reefs have suffered in recent decades, including the work and techniques being developed by both Foundations.

It is therefore a work of optimism, with a powerful underlying message: Together we can make a difference!

Thank you for your interest,

MSC Foundation


At the Ba’a Foundation, we firmly believe that addressing environmental challenges requires partnership and collective action. We are fortunate to have formed strong relationships with likeminded organizations, and together we have been able to achieve significant milestones in our environmental efforts, especially those related to coral reefs.

We extend our deepest thanks to our esteemed partners, who have played an instrumental role in the success of these endeavors. Their unwavering support, expertise and shared vision have enabled us to implement practical solutions that drive positive change.

Our partners have contributed invaluable resources and insights, allowing us to maximize


the impact of our initiatives and create sustainable practices that benefit both the environment and society. We would therefore like to express our gratitude to the following partners who have been integral to our environmental initiatives: National Center for Wildlife, King Abdullah University of Science and Technology, Beacon Development, MSC Foundation.

Each of our partners has brought unique perspectives and strengths to the table, enriching our efforts and helping us develop comprehensive strategies to address environmental challenges. Their dedication and commitment to our shared goals have been truly commendable.

Together, we can continue to create a greener and more sustainable future for generations to come.

As we move forward, we remain steadfast in our commitment to environmental conservation and sustainable development.

Ba’a Foundation



First and foremost, our sincere appreciation goes to Prof. David J. Smith, PhD, for his co-authorship and exceptional dedication. We are likewise deeply grateful to the coral experts of the King Abdullah University of Science and Technology for their invaluable co-authorship, the Ba’a Foundation Secretariat for its team support, and to Dr. Owen R. O’Shea, Marine Programme & Research Manager of the MSC Foundation, for his essential contributions to the peer review process.

We express our special gratitude to Dr. Sylvia Earle for her generous input, which has enriched the scope of this book. We are truly honoured by her involvement.

Additionally, we thank everyone in the MSC Foundation’s communication and operations teams for their outstanding engagement and dedication throughout the project. Your collective efforts have made this book a reality, and we are profoundly grateful for your contributions.

We want to express our deepest gratitude to the MSC Cruises guests and generous donors whose unwavering support has been instrumental in bringing this book to life.

Lastly, we would like to acknowledge and celebrate all those who dedicate their lives to finding lasting solutions to restore and conserve the Blue planet.

5 Acknowledgements & Forewords


For millions of years coral reefs have wrapped the warm sunlit seas of Earth’s tropical midsection like a jeweled belt, crowning undersea mountains, bordering continents, fringing oceanic islands and providing shelter and sustenance for a galaxy of colorful creatures. While occupying less than 1% of the area of the ocean, coral reef systems host an extraordinary diversity of species representing more than twice as many phyla of animals than all terrestrial and freshwater systems combined.

The renowned scientist, Charles Darwin, devoted his first book, “The Structure and Distribution of Coral Reefs,” to an analysis of how atolls, fringing and coast-hugging barrier reefs were formed, based on his observations during an 1831-1836 global expedition. In Voyage of the Beagle, he wrote, “…..travellers tell us of the vast dimensions of the Pyramids and other great ruins, but how utterly insignificant are the greatest of these, when compared to these mountains of stone accumulated by the agency of various minute and tender animals!”

I first glimpsed of the splendor of coral reefs as a young scientist in 1954, soon after my first experience using scuba. In the Florida Keys, I was mesmerized by towering stands of elkhorn and staghorn corals glittering with small fish, by bright red starfish and speckled crabs, clusters of electric blue sea squirts, luminous purple sponges,

and brilliant yellow whorls of polychaete worms embedded within giant mounds of brain coral. As I swam, an entourage of curious fish followed, mouthing my trail of exhaled bubbles , stopping when I stopped, moving when I moved. Most insistent were poodle-sized groupers, muscular fish clothed in sleek gold and brown jackets of scales, who watched over my shoulder as I poked and prodded crevices among the dense stands of coral.

Over the decades since, during explorations in the Atlantic, Pacific and Indian Oceans, with years at sea and thousands of hours under the sea, I have witnessed changes in the ocean that are of geological magnitude. About half of the coral reefs are gone, along with coastal seagrass meadows, mangroves and marshes, largely to make way for various human constructions, coupled with overarching impacts that are changing the nature of the planet overall. If Darwin could magically retrace his voyage in the 21st century, he would likely be shocked at how much has been lost of that lacey garland of reef plants and animals that once spanned the shallow blue waters of the globe between 30 degrees North and 30 degrees South.

Two centuries ago, the ocean seemed so vast, so resilient, that it seemed there was little humans could do to alter its nature. Now we know: Unprecedented human activity is driving global warming, climate change, sea level rise, pollution,

acidification of the ocean, loss of species and entire ecosystems. Current trends could lead to the disappearance of coral reefs before the end of this century, their existence recorded as distant memories, haunting images and dusty museum specimens. But it does not have to be that way.

I have personally witnessed loss – and recovery –of places described in this book in the Bahamas, the Caribbean, the Red Sea and elsewhere in the world. Countries are beginning to come together to protect biodiversity and address the root causes of climate change and pollution. It is heartening to see individuals, corporations and philanthropic organizations providing vital resources aimed at positive change.

Knowing is the key to caring, and in the pages that follow there is ample evidence that knowledge is leading to meaningful actions to scale up protection of coral reefs that are in good health and to restore degraded systems.

Bravo to the authors, contributors and supporters of this beautifully illustrated, authoritative volume for providing not only a comprehensive review of the past, present and future of coral reefs, but most importantly for highlighting reasons for hope.

Coral Reefs: Challenges and Conservation in the Caribbean and the Red Sea


Coral reefs are the rainforests of the sea. They are home to a wide variety of fascinatingly coloured fish with remarkable diversity. Reefs are extremely productive, shallow-water marine ecosystems, the foundations of which consist of hard limestone structures formed through successive growth, deposition, and consolidation of reef-building corals and coralline algae.

Reefs: Challenges and Conservation in the Caribbean and the Red Sea
Image: A healthy, shallowwater coral reef.
9 Introduction to coral reefs

The basic unit of a coral, and hence the reef, are the coral polyps which live in symbiosis with microscopic algae that live inside the coral tissue. The microscopic algae provide the majority of coral species with most of the food they require to grow – in many cases more than 90% of the energy requirements of a coral comes from the photosynthetic activity of its microalgae. The rest comes from suspension feeding activities of the polyps themselves. In return, the microalgae have a safe place to reside and receive essential nutrients through the waste products of the coral. It is a truly remarkable mutualistic relationship that benefits both parties and results in corals being able to produce the large structures that we recognise as coral reefs. This symbiotic relationship is the key factor that drives the extreme productivity of reefs and defines the rather strict environmental requirements of reef building corals (Cesar, 2022).

When we see a coral, we are looking at many thousands of interconnected coral polyps living in a colonial fashion, sharing resources, and secreting calcium carbonate skeletons that build highly complex reef structures. These provide shelter and habitat for many thousands, if not millions, of species including small invertebrates and fishes. Some large invertebrates and fish feed on these small organisms which drives a diverse ecological system. Coral reefs, due to their physically complex nature, also act as nursery grounds for species that as adults are found in other marine ecosystems. Similarly, many species which reside as juveniles in connected ecosystems such as seagrasses and mangroves, migrate on to reefs as adults.

As well as being the most biologically diverse ecosystem in the ocean, coral reefs interconnect with adjacent ecosystems to play an extremely

important role in the food web and ecology of tropical coastal as well as pelagic regions around the world. Many charismatic species visit reefs at different times of the day or year to feed or reproduce. Species such as whale sharks are known to feed within reef systems during the time of coral mass spawning – an incredible time of year when most corals, in a specific region, spawn eggs and sperm that fertilise to become small coral larvae that disperse to eventually form new corals. This pulse of biological activity attracts many species of megafauna to capitalise on the mass food availability.

Reefs not only underpin local biodiversity but also support the diversity of many other marine ecosystems. They are a marvel of the natural world that provide important ecological functions and ecosystem services, including the provision of food security as well as coastal protection for hundreds of millions of people. The goods and services provided by coral reefs form an important source of income to local populations, often living at subsistence levels. They are also a potential tourist attraction, thereby contributing to local income generation. Coral reefs generate an estimated US $2.7 trillion globally through fisheries and recreation (Souter et al., 2020). On top of these important ecological and economic benefits, coral reefs represent a unique ecosystem with important global biodiversity value as well as scientific and educational value.

Currently, coral reefs are being depleted rapidly in most locations around the world due to destructive fishing practices such as poison fishing and blast fishing, overfishing, coral mining, marine pollution, and sedimentation among others. Scientists estimate about half of all coral reefs have been lost

in the last 70 years due to climate change, habitat destruction, exploitation, and pollution (Burke et al., 2011; Hughes et al., 2018; Eddy et al., 2021). It is predicted that unless stressors are curbed by 2050, 90% of all tropical reefs will be lost, and almost all reefs will be classified as threatened (Burke et al., 2011 Elias, 2018). Such a loss will majorly deplete fisheries, costing US $6.8 billion a year globally (“Reef Fisheries,” 2018) and reduce food security in numerous coastal communities (Cabral et al., 2018). At the global level, ocean acidification ultimately caused by increasing atmosphere carbon dioxide concentrations and thermal-induced coral bleaching, caused by the increasing frequency and intensity of marine heatwaves, are driving reefs to the edge of extinction. Coral reefs are threatened by global as well as local factors and those who benefit economically from reef exploitation are not always the same as those communities whose livelihoods are most at risk from the loss of reefs and the services they provide.

It is now widely accepted that without direct intervention to protect coral reefs from these threats, and the restoration of damaged reefs which have lost the ability to recover on their own, these spectacular and unique ecosystems could disappear from the planet in the next 30 years.

Image: A napoleon wrasse swims above a busy reef adorned with soft corals. Coral Reefs: Challenges and Conservation in the Caribbean and the Red Sea


The phylum Cnidaria, to which corals belong, includes a wide range of living species such as jellyfish and sea anemones. When we talk about a single coral, we refer to a single polyp, whilst coral colonies are made up of hundreds of thousands of tiny polyps.

Image: Reef forming corals in the Bahamas Coral Reefs: Challenges and Conservation in the Caribbean and the Red Sea
The biology of reef-forming corals

Coral polyps look like tiny sea anemones and have tentacles that usually only come out during the night to allow corals to feed on plankton in the water column. The tentacles are packed with specialised stinging cells called nematocysts that are used to sting prey and to defend the coral from predators and competitors. The tentacles can also be used to clear away any debris that may settle on the surface tissue of the polyps. Most importantly, inside the tissue of each polyp live symbiotic zooxanthellae (microscopic algae) which are critical for the success of corals.

“Coral polyps look like tiny sea anemones and have tentacles that usually only come out during the night to allow corals to feed on plankton in the water column.”

The clonal coral polyps secrete hard calcium carbonate cup-like structures called corallites within which polyps sit and are protected. These interconnected corallites form the coral colony and differently shaped colonies provide the complex physical structure of a reef. Here we see eggs and sperm bundles being released by interconnected corallites.

Zooxanthellae are microscopic single-celled algae that belong to the dinoflagellate group. There can be hundreds of thousands to millions of zooxanthellae per square centimetre of coral tissue. The coral animal forms a symbiotic relationship with these zooxanthellae.

The coral host provides zooxanthellae with a protected environment and nutrients, while zooxanthellae provide the coral with glucose produced through photosynthesis. Zooxanthellae provide the coral with much of its coloration although the animal itself also provides pigmentation.

Coral Reefs: Challenges and Conservation in the Caribbean and the Red Sea
“Around 25% of all marine species call coral reefs their home, despite coral reefs only occupying 0.1% of the ocean.”

There are two main types of coral that occupy reef environments. These are soft corals and hard corals, otherwise known as reef-building corals. There are about 6,000 coral species found around the world, of which 850 species are reef builders found in tropical waters.

Tropical reefs are formed when many different corals produce hard, calcareous skeletons. Many other organisms also secrete calcium carbonate and, together with the reef building corals, they form the robust and complex habitat that provides a home to so many different species. Around 25% of all marine species call coral reefs their home, despite coral reefs only occupying 0.1% of the ocean. Coral reefs exist in a dynamic equilibrium –there are processes that continually build up the reef, such as coral growth, and there are processes that erode the reef. These include physical factors such as wave energy, and also biological processes such as coral predation carried out by some species of fish (for example several species of butterflyfish and some parrotfish), as well as several invertebrate species. These erosive processes are important for tropical coastal ecosystems as they produce new sand that can replenish tropical

beaches. But generally, a healthy reef system is one that is in a positive state of growth where production of calcium carbonate outweighs the loss of calcium carbonate. From this perspective, coral growth is extremely important. Factors that reduce growth rates are damaging to reef ecosystems.

Coral growth largely dictates the growth of the reef system, but the growth of reef systems also depends on the recruitment of new corals. A thriving reef system typically exhibits robust coral recruitment resulting from sexual reproduction and the settlement of new corals. In the same way, new reef habitat is also formed, so coral reproduction and recruitment are extremely important to ensure the continued survival of reefs. Sexual reproduction of corals is complex but largely follows two forms: broadcast spawning and brooding.

It is thought that around 75% of reef-building corals reproduce through broadcast spawning when, at specific times of the year, corals release eggs and sperm into the water column (nearly always at night). In some species, coral colonies have different sexes whereas in other species, the same colony can produce both eggs and sperm.

The sperm fertilises the released eggs within the water column to produce a planula larva. It is these larvae that disperse for a relatively short time (several days to several weeks) with currents until they metamorphose and settle on the seafloor to develop into a single ancestral polyp. Through asexual division the ancestral polyp then divides into two offspring polyps thereby initiating the growth of a new coral colony.

In the remaining 25% of coral species that utilise brooding, the eggs are retained in the coral polyp and only sperm are released into the water column. The sperm finds its way into neighbouring corals to fertilise the internal eggs which then develop into a relatively mature planula larva. The planula larvae are released into the water column, disperse, and in a relatively short time (and distance) settle on to suitable substrates before metamorphosing into the ancestral coral polyp which goes on to divide to form a coral colony. Sexual reproduction, larval dispersal and coral recruitment are key to the future survival of reefs and are taken into account during the design of conservation strategies.

The biology of reef-forming corals


Factors that threaten coral reefs around the world can be divided into those directly induced by human activity and those that are naturally occurring. Threats that are human induced can be further divided into those that operate at a local scale and those that are global.

Image: Plastic pollution is a plague on the ocean. Coral Reefs: Challenges and Conservation in the Caribbean and
the Red Sea
17 Threats to coral reefs
Image: Human development defines some coastlines.
in the Caribbean and the Red Sea
Coral Reefs: Challenges and Conservation
“Over the past century, human population growth has been significant, particularly in coastal regions.”


In recent times, coral reef environments have faced numerous local threats. Over the past century, human population growth has been significant, particularly in coastal regions. Rapid urbanisation and industrialisation have brought about challenges, including activities that have ultimately led to the damage or loss of coral reef habitats. The main threats at a local level are:

1. Adverse fisheries: including overfishing, some aquaculture development, and destructive fishery practices.

2. Coastal development: heavy construction, port activities, including landfilling and dredging, and urban runoff.

3. Pollution: urban sewage, agricultural runoff, shipping, as well as industrial discharges.

4. Marine litter: macro- and microplastics from improper disposal.

5. Coral harvesting: mining activities and collection.

6. Unsustainable tourism practices.

Threats to coral reefs


Despite having local impacts, due to the fact that most reefs around the world have been impacted, overfishing should also be considered a global issue. Approximately 55% of all coral reefs in the Red Sea are reported to be suffering from the effects of fishing pressure (Fine et al., 2019; Burke et al., 2011), while 33% of Caribbean reefs are at high threat from fisheries pressure and 30% at medium threat (Burke & Maidens, 2004).

Overfishing damages coral reefs, mainly by reducing fish diversity and biomass, including the removal of large predatory species such as sharks. At present, fish populations in the Red Sea, including sharks, are significantly reduced compared to historic numbers. In contrast, in The Bahamas, action has been taken to reduce impacts of fisheries on sharks. It is now a country considered to have relatively stable shark populations (Gallagher and Hammerschlag 2011). In 2011, the Commonwealth of The Bahamas designated its entire Exclusive Economic Zone as a shark sanctuary which has resulted in relatively healthy shark populations and demonstrates the value of protective governance on vulnerable species (Haas et al 2017).

“Sharks play an important role in promoting healthy coral reefs and are on many tourists’ ‘bucket lists’.”

Sharks play an important role in promoting healthy coral reefs and are on many tourists’ ‘bucket lists’. Sharks maintain food webs and fish stocks, promote the cycling of nutrients, reduce disease, and help regulate invasive species. By eating large predatory fish species such as groupers, sharks regulate their numbers, and maintain a healthy population structure. This, in turn, results in a greater abundance and diversity of smaller fish that constitute the grouper’s prey, some of which are algal grazers. Overfishing decreases the value to recreational divers who are eager to see both large predators and an abundance of small colourful fish. In the Red Sea, comparisons of different reefs demonstrates that the Eastern Red Sea reefs are more severely impacted by overfishing than the Western Red Sea. Many of the diving tourists to Sudan are attracted by the high numbers of reef sharks. Similarly, shark tourism is big business in The Bahamas, with many tourists visiting the islands specifically for the opportunity to dive with large shark species such as great hammerhead and tiger sharks. The presence of sharks on reefs is a good sign and is indicative of a healthy ecosystem.

It is not only the apex predators that are important in regulating community structure and a healthy

reef system. Many different fish species play important roles in maintaining the diversity of coral reefs. Perhaps the best-known examples are species that graze directly on macroalgae (seaweeds). Without being grazed excess macroalgae can overgrow corals, thus depriving them of access to the light required for their internal symbionts to photosynthesise. They can also reduce the space available for coral growth and attachment of the new colonies that are essential for reef development and replenishment. There are many examples around the world where overexploitation of key fish groups has resulted in a dominance of macroalgae with consequences for the physical structure of the reef and the diversity of the entire system.

In general, the necessary reduction in effort to avoid overfishing and achieve optimal sustainable yields is in the order of 60% globally. Alternative income generation, such as ecotourism, could be one potential way of bringing about this reduction in effort. Besides lowering the total effort, fisheries management efforts should also focus on the creation of sanctuaries or no-take zones and the establishment of closed seasons to allow fish communities to recover and prosper (Cesar, 1996).

Coral Reefs: Challenges and Conservation in the Caribbean and the Red Sea
Threats to coral reefs
Image: Large species play critical roles in reef health.


The development of fin-fish and prawn farms along the coast of the Red Sea has occurred within designated protected areas (Berumen et al, 2019). The potential of aquaculture to underpin national food and economic security has also been noted by the Bahamian authorities. But despite its potential value, care must be taken and there have been several recorded escape events of non-native fish from open-sea enclosures within the Red Sea. The impact of the introduction of these species into the ecosystem is currently unknown, but there are concerns for the health of the already degraded reef fish communities.

As well as escapes, the effluent from fish and prawn farms can cause substantial stress and direct damage to reef habitats, the effects of which may extend over large reef areas. Uneaten fish food preparations and faecal material can be dispersed widely around mariculture cages, but will eventually settle on the seabed. This introduces catastrophically high levels of nutrients into an environment that supports specialised marine communities which have evolved specifically to thrive in water of low nutrient content. In addition, other chemicals used in the rearing of cultured species, such as antibiotics or pesticides, may also have damaging impacts on coral colonies or the associated communities that live in, on or around them. Moreover, the worldwide transport of aquaculture stock has long been known to be a source of disease outbreaks in native species.

“The worldwide transport of aquaculture stock has long been known to be a source of disease outbreaks in native species.”
Coral Reefs: Challenges and Conservation in the Caribbean and the Red Sea


Though now illegal in almost all countries around the world, and despite the obvious dangers, home-made explosives are still used in many regions as an easy and quick way to catch entire schools of reef fish and small pelagic species. In the past, explosive charges have been obtained from recovered World War II ordinance, from mixing fertiliser and kerosine, or from illegally obtained dynamite, often procured from local civil engineering projects. The blast shatters the stony corals and kills fish and invertebrates in a wide surrounding area. Over time, sustained blast fishing will damage entire reefs and deprive subsistence fishers of the resource on which they rely for their livelihood (Cesar, 2022). This highly destructive fishing technique often creates vast rubble fields. The mobile rubble produced by blast fishing also prevents successful coral settlement, thereby reducing the ability of the reef to recover on its own. Blast fishing has been reported to occur in the Red Sea but is likely to be rare in Caribbean regions, including within The Bahamas.

Left: A pair of bannerfish on a healthy reef.
Threats to coral reefs
Right: The effects of blast fishing on a coral reef.
Image: Human influence is evident along many coasts.
in the Caribbean and the Red Sea
Coral Reefs: Challenges
and Conservation
“The creation of greater access to the waterside … will inevitably result in the loss or degradation of nearshore habitats including coral reefs.”


The past few decades have seen larger coastal populations around the Red Sea, and rampant development extending from the Gulf of Aqaba to the length of the Eastern Red Sea. Landfilling for coastal and port development can destroy coral reefs. The creation of greater access to the waterside, such as quayside amenities in ports, retail units, tourist accommodation and residential waterfront properties, will inevitably result in the loss or degradation of nearshore habitats including coral reefs, particularly if those habitats fall within the footprint of a development or construction project. The increase in marine transportation and the expansion of Red Sea ports to accommodate the growth of such activity has presented a documented threat to coral communities. Commercial activities in Eilat and Aqaba ports, for example, have increased dramatically in recent years, including the transport of goods, and an increase of passengers and container terminals, oil terminals, mineral export facilities, naval bases and marinas. Some damage to reefs has been observed as a result of direct dredging on the coast, and due to increased sedimentation rates caused by construction and road expansion, especially in port areas (Fine et al, 2019).

With over a tenth of global trade passing through the Red Sea on the way to the Suez Canal, about 50 ships per day use the route along the Red Sea. This route is important to transport energy, commodities, consumer goods and componentry dispatched from Asia and the Middle East to European destinations. The canal’s location also makes it a key regional hub for shipping oil and other hydrocarbons. It enables the transfer of a tenth of the world’s oil and liquefied natural gas. Approximately one million barrels of oil traverse the Suez Canal daily. Oil pollution from oil terminals and pipeline bursts constitute significant environmental hazards in some areas of the Red Sea. Several oil spills were reported in 2016 near to the flourishing coral reefs of Egypt, while a 200-tonne oil spill in Aqaba was fortunately cleaned before causing any damage to the reefs (Mine, 2019). A large oil spill incident would have catastrophic consequences for the coral communities in any area of the Red Sea.

Between 1990 and 2000, the population living within 10km of the Caribbean coast grew from 36 million to 41 million. Increases in coastal zone population density leave reef resources susceptible to exploitation to provide livelihoods

and sustenance to coastal communities. Coastal development resulting from population growth and intensive tourism, along with overfishing, threatens over 80% of Caribbean reefs. The highest urbanisation rates in the English-speaking Caribbean are within Nassau, New Providence Island in The Bahamas, where studies have found urban growth extends across the entire island. According to the United Nations Department of Economic and Social Affairs Population Division (World Urbanization Prospects: The 2018 Revision), around 84% of the Bahamian population now live in urban areas and coastal development and population rises have put pressure on natural resources in many locations.

In the Caribbean region, indirect effects of urbanisation include, to runoff of sediments due to under-regulated coastal development of roads and hotels, to nutrient pollution from runoff from golf courses and untreated or minimally treated sewage from hotels, to poorly managed cruise ship operations, and cesspits (Jackson et al, 2014). Once again, these inputs alter the ecological balance of coral reefs as they most often result in decreased coral growth and increased algal abundance to the detriment of reef complexity and biodiversity.

Threats to coral reefs



Marine litter constitutes a substantial and evergrowing global threat to the marine environment. Discarded plastic is by far the most pervasive component of human refuse that enters the sea. In the Red Sea and the Caribbean region, as with many other parts of the world, this comes typically in the form of plastic bags, bottles and discarded or lost fishing gear. All of these are virtually indestructible and will remain in the water column or on the seabed for hundreds of years, albeit probably continually being broken down into smaller fragments over time. Marine surveys have found plastic objects in every location where they have looked – even on the deepest ocean sea floor.

Marine litter, particularly plastics, present a range of threats to coral reef communities. Drifting debris may snag on hard coral, breaking or physically damaging the skeleton. It could also cover them, denying access to light, causing their photosynthetic symbionts to die and the coral to bleach. Reef-associated fish and larger animals may become entangled, often leading to death. Floating or drifting debris can also act as islands or rafts, transporting non-native and sometimes invasive

species to new locations where they become a disruptive and damaging influence within native communities. In addition, toxic chemicals such as organic pollutants are known to be absorbed and concentrated on plastic surfaces. There is also evidence that corals brought into contact with plastics are 20 times more likely to be affected by disease (Lamb et al. 2018).

Smaller plastic fragments and deliberately manufactured microbeads used in the cosmetic industry, collectively known as ‘microplastics’ (defined as less than 5mm in length), present a particular problem. They are commonly mistaken for food and ingested by smaller organisms that are important components of the wider marine food chain. Apart from gaining no nutritional value from its microplastic meal, the animal may be exposed to elevated levels of organic pollutants that have been absorbed and concentrated on the plastic. These toxins then have the potential to be transferred to other organisms and further concentrated as natural predation processes carry them further up the food chain.

Reefs: Challenges and Conservation in the Caribbean and the Red Sea
“Discarded plastic is by far the most pervasive component of human refuse that enters the sea.”
Threats to coral reefs
Image: Floating plastic is a common sight in the ocean.


Coral skeletons have long been used for building material and in the production of lime. They are also extensively traded in the aquarium, ornamental, curio, and jewellery industries. Coralderived lime is often used as plaster or gets mixed with cement to reduce costs in the construction of private dwellings and local administrative offices. Coral harvesting or mining destroys valuable reef habitats such as shallow reef flats that provide shoreline protection. It may also indirectly lead to the depletion of secondary forests used for the burning process in coral lime preparation.

Left: A large sea fan

Right: Divers explore a coral outcrop off Kosrae, Micronesia

Coral Reefs: Challenges and Conservation in the Caribbean and the Red Sea
“Carribean reef-related activities and tourism attract more than 11 million visitors per year, generating US $8 billion.”


Coral reef associated tourism has been a major source of income for many Red Sea and Caribbean countries since the early 1980s. Both are favoured ‘sun and sea’ holiday destinations. To date, the bulk of Red Sea coastal tourism has been concentrated along Egypt’s Sinai and eastern coastline, with a contribution of over 3.5% to Egyptian GDP, though this is likely to change with the major projects developing along the Saudi Arabian Red Sea coastline (Fine et al, 2019).

Tourism is the lifeblood of many Caribbean nations and approximately 65% of all its reefs are frequently visited by tourists. Approximately 15% of the region’s GDP comes from the industry.

Carribean reef-related activities and tourism attract more than 11 million visitors per year, generating US $8 billion. However, evidence demonstrates that high densities of both tourists and residents are harmful to reefs unless environmental protections are comprehensive and effectively enforced.

The presence of healthy and colourful coral reef habitats, easily accessible within a development area, are seen as primary assets for attracting paying visitors. Their preservation is regarded as a priority in all development projects. But there remains critical conflicts and impacts that arise when exposing coral reefs to tourism activities, however they are managed or controlled. Creating a tourist destination requires significant coastal and shoreline construction and the establishment of infrastructure and services, such as waste management systems. In the past, rapidly developing tourism centres have resulted in substantial litter and sewage pollution discharges. These impinge on coral health. In addition, poorly managed or controlled diving and snorkelling activity, coupled with unregulated boat anchoring, has often led to significant coral damage where trampling, diver collision and anchor dragging

has occurred. As visitor numbers increase, diving activities at some sites becomes unsustainable.

Recently, concern has also been raised about the chemical components in sunscreen (extensively used in tourist resorts) and its impacts on corals. Laboratory studies have shown that the chemical UV filters commonly found in many cosmetics and sunscreen products are highly toxic to corals, even at very low concentrations, and will rapidly kill juvenile corals (Downs et al, 2014). It remains unclear whether the levels of sunscreen chemicals found in the sea surrounding popular Red Sea and Caribbean resorts are comparable to these experimental concentrations.

Threats to coral reefs
Image: A heavily degraded coral reef.
in the Caribbean and the Red Sea
Coral Reefs: Challenges and Conservation


Currently, the main global threats impacting coral reefs are those caused by the increasing frequency of marine heatwaves and ocean acidification.

“Marine heatwaves are becoming more common. If temperatures remain high the corals die.”
Threats to coral reefs
Image: A diver swims over a dying reef.
Coral Reefs: Challenges and Conservation in
Caribbean and the Red Sea
“As marine heatwaves become more severe, we are seeing more episodes of mass coral die off.”


As the ocean absorbs excess carbon dioxide from the atmosphere, its surface waters become more acidic. Carbon dioxide alters the chemistry of seawater by reducing pH, a measure of acidity. Water that has a lower pH level is more acidic and lowers the availability of carbonate ions which are used by corals to make calcium carbonate. This decreases the growth rate of corals and affects their structure leading to more breakages of the colony and degradation of the reef.

Coral bleaching is a phenomenon that is primarily caused by marine heatwaves, defined here as a relatively short-term spike in seawater temperatures, ranging from a few weeks to a few months. Corals most often live very close to their thermal maximum. This means they are adapted to living at their upper thermal ranges, which maximises their chances to succeed in a very competitive environment. If local temperatures rise by just a few degrees above the long-term average for more than a few weeks, the key relationship between the microalgae within the tissue of the coral and the animal itself breaks down. This breakdown in the relationship creates harmful

metabolites that can cause mass disruption to the coral (see Suggett and Smith 2020). Marine heatwaves are becoming more common. As the relationship between coral and algae breaks down, most of the algae are ejected from the tissue of the coral, and consequently the coral starts to lose their colour – this is the process of coral bleaching. If temperatures return to normal within a few days or weeks, many coral species can repopulate their tissue with algae, there colour returns and they survive. If, however, temperatures remain high for prolonged periods of time (typically over four weeks), the corals will eventually starve or become so impacted by metabolites produced by the heatdamaged microalgae, that they die.

Not all coral bleaching leads to the death of the coral (See Suggett and Smith 2011), but as marine heatwaves become more severe, we are seeing more episodes of mass coral die off. Climate change models predict that marine heatwaves will continue to increase in severity over the next few decades, leading to the likelihood of increasing global mass bleaching events. It is crucial to find solutions to this serious global problem.

The Red Sea’s location provides a convenient gradient for studies of latitude-dependent globalscale impacts, such as acidification and ocean heat content. Data from two decades shows that Red Sea coral reefs are showing signs of climate change impacts with communities becoming less diverse with fewer species (called homogenisation) alongside declines in coral colony size (Riegel et al, 2012).

Coral bleaching has had a significant impact on the reefs of the Caribbean, which is considered one of the world’s most vulnerable regions. Over the last 30 years there have been at least 65 separate heating events throughout the entire Caribbean region that have resulted in bleaching, although the extent of that bleaching varied across different reef sites (Muniz-Castillo et al 2019). At the time of writing, the Caribbean region, and in particular coral reefs off the coast of Florida, are facing one of the most severe marine heatwaves ever recorded in the area, with mass coral bleaching and mortality being reported throughout the region.

Threats to coral reefs

Global action to reduce the rate and extent of anthropogenic-driven climate change is key to the future success of coral reefs. But interim measures are also needed to ensure the survival of coral reefs in the short- and mid-term. For example, preparing coral reefs to be better able to absorb external shocks, such as marine heatwaves, involves maximising coral species and genetic diversity and maximising the health of the whole ecological system. Healthy and diverse ecosystems are more resilient and able to respond to and recover from environmental disturbances much better than if they are in a state of degradation prior to the onset of the disturbance. The protection and conservation of coral reefs to maximise their biodiversity and general health status is therefore paramount. But there are also other options available to us to ensure the future is one which has coral reefs. For example, there are some reef regions that are naturally less vulnerable to climatic events such as marine heatwaves. These “refuge” environments, which may be entire reef regions or more local reef sites, should be a priority for the strictest protections (see Osman et al 2018).

In many areas of the world, coral reefs have been so damaged that they have lost their natural ability to recover. Here, conservationists can undertake direct intervention to kick-start the natural recovery

processes. This is where restoration approaches can be most valuable. These include establishing new coral populations (via out-planting of coral fragments into new environments) as well as habitat augmentation (e.g., introducing new structures to provide a suitable substrate for corals to recruit on to). Some restoration projects also use scientific understanding of coral thermal tolerance in their efforts to regenerate damaged areas (see Shaver et al 2022). For example, there are some coral populations that have combined forces with heat-tolerant microalgae. These unique partnerships seem to do much better under marine heatwave conditions than others. The search is therefore on for those coral-algae populations (sometimes termed “super corals”) that can be propagated and used within a restoration setting to increase the net resilience of that system to climate change events. However, it is important when deciding which coral species to restore, to consider the native coral community as a blueprint. Reefs need coral species that deliver specific ecological functions and ecosystem services, as well as species and populations that stand the best chance of surviving future environmental conditions. Restoration is expensive and complex and should be done with care and consideration.

“There are some reef regions that are naturally less vulnerable to climatic events such as marine heatwaves.”
Image: A dive boat sits amid a sprawling reef system. Coral
Reefs: Challenges and Conservation in the Caribbean and the Red Sea
“The urgency of addressing coral diseases has been recognised by scientists, conservationists and policymakers.”
Image: A marine biologist collects reef data.



Corals, like any other animal, are impacted by disease. There are examples where disease outbreaks have decimated reefs around the world. Coral diseases, driving the decline of reefs, have become a significant challenge in recent decades. Coral disease outbreaks are caused by several factors which often coincide with environmental stressors and correlate with human activities.

Elevated sea surface temperatures, for example, appear to be a primary contributor to coral disease outbreaks. When temperatures exceed the normal range, corals become more susceptible to pathogens, compromising their immune systems. Additionally, pollution, nutrient runoff, and sedimentation from human activities can disrupt coral health and increase disease susceptibility. The spread of coral pathogens through shipping and ballast water may also play a role.

The impacts of coral diseases extend beyond the affected corals themselves. When coral diseases lead to the loss of coral colonies, ecosystem services are compromised. The decline of corals (and the habitat they provide) disrupts the intricate ecological balance of a reef ecosystem, negatively impacting fish populations and other marine organisms that rely on corals for shelter and food. The aesthetic value and recreational appeal of reefs

may also be diminished, affecting local economies and communities dependent on tourism.

Coral diseases manifest in different ways, ranging from tissue loss diseases to skeletal anomalies. Common examples include white band disease, black band disease, and coral tumour-like growths. Each disease has its unique characteristics, but they all share the common effect of causing tissue damage or mortality, leading to the overall decline of coral health and reef structure. In recent years, coral reefs of the Caribbean, and more recently The Bahamas, have been impacted by a specific disease termed Stony Coral Tissue Loss (SCTL).

SCTL was first documented off the coast of Miami in 2014 and is characterised by the rapid loss of coral tissue leaving behind exposed skeletal structures. The disease can progress rapidly, leading to significant coral mortality and reef degradation. For example, SCTL only reached the iconic Mesoamerican Reef System in 2018 but managed to spread throughout the 450 km of reef system within a few months. SCTL mostly impacts large boulder-like corals with 21 commonly impacted species being recorded (Alverez-Filip et al 2022). This specific disease is likely to become one of the most significant and lethal impacts ever to hit Caribbean reefs and the race is on to

better understand the pathogens involved, modes of transmission and most importantly, the best mitigation strategies.

The urgency of addressing coral diseases has been recognised by scientists, conservationists and policymakers who are collaborating to implement conservation strategies. These efforts include:

1. Disease monitoring and research focusing on disease prevalence, outbreak patterns, and potential causes.

2. Enhancing reef resilience to mitigate the impacts of diseases. Strategies such as coral reef restoration, reducing pollution and sedimentation, and addressing climate change.

3. Bespoke disease management including innovative treatment approaches such as the development and deployment of probiotics to enhance coral immunity.

37 Threats to coral reefs


Corallivores are those animals that feed directly on corals. Generally, and under normal conditions, they are important components of the intricate coral reef food web and cause no major damage. However, under certain conditions, specific corallivores can increase in density (or “outbreak”). When this happens, they can have significant impacts on coral populations and reef health.

Corallivores encompass a diverse range of organisms, including fish and invertebrates such as some species of snails, sea stars and sea urchins. They have evolved specific adaptations to feed directly on coral tissue. Perhaps the best-known example of a corallivore that can cause mass damage to a coral reef when they outbreak, is a large starfish commonly known as the Crown of Thorns starfish (COTS). The COTS is a species that has gained much attention due to its significant impact on coral reefs in several different ecoregions, most notably the Great Barrier Reef, but also the Red Sea. It has not yet been reported in the Caribbean. COTS are voracious predators that, when present in large numbers, can cause extensive damage by devouring vast areas of coral.

“The best-known example of a corallivore that can cause mass damage to a coral reef ... is the Crown of Thorns starfish.”

The resulting decline in coral cover and diversity disrupts the delicate balance of the ecosystem, impacting associated species and compromising the overall health and resilience of the reef. Several different reasons have been put forward to explain COTS outbreaks:

1. Natural population cycles of COTS with periodic outbreaks occuring every few years. During these outbreaks, numbers can explode due to favourable conditions, such as availability of food and possibly optimum temperatures.

2. Nutrient enrichment caused by excessive nutrient runoff from human activities, such as agricultural practices and coastal development, can promote algal blooms. This is an additional food source for COTS larvae, resulting in higher survival rates and eventually increased adult population sizes.

3. Overfishing of natural predators of COTS, such as certain species of triggerfish and triton snails, might result in reduced predation pressure allowing COTS populations to thrive unchecked.

COTS have had the biggest impact on the Great Barrier Reef where entire reef systems have been devastated. The Red Sea has also been impacted by COTS outbreak with significant events being recorded in the last few decades. Conservation efforts and mitigation strategies are varied ranging from direct removal, poisoning the starfish in situ, employing biological agents to induce mortality, and the restoration of predator populations. Early detection of possible outbreaks is needed as is a greater understanding of the exact reasons why outbreaks occur so that appropriate mitigation may be implemented.

Image: A Crown of Thorns starfish Coral Reefs: Challenges and Conservation in the Caribbean and the Red Sea
39 Threats to coral reefs


Invasive species are non-native organisms that are introduced into new habitats, often due to human activities, which can pose a significant threat to marine ecosystems worldwide. In the marine environment, invasive species can include plants, animals, and microorganisms that disrupt the balance of native ecosystems. Once established and often without any natural predators, they can outcompete native species for resources, alter habitat structures, and negatively impact biodiversity and ecosystem function. One of the worst examples of an invasive species on coral reefs is the common Indo-Pacific lionfish that was accidently introduced into coral reef ecosystems of the Caribbean where they have had devastating ecological impacts since.

Lionfish are voracious predators with a diverse diet that includes small fish and invertebrates. They have few natural predators in their nonnative range, allowing their populations to thrive unchecked. This high predation pressure can result in the depletion of native fish populations, disrupting the balance of coral reef food webs. Lionfish also have few competitors in their new environments, giving them a competitive edge over native species.

Several possible causes of the introduction of lionfish into the Caribbean have been put forward, including introduction through the aquarium trade, either accidentally during adverse weather or on purpose. Regardless, their high reproductive capacity and lack of natural predators have resulted in significant impact across the entire Caribbean region, leading to several initiatives aimed at population control. These include direct removal, increasing consumer demand for lionfish as a local food resource, and mass public awareness campaigns focusing on the need to report, remove and control populations. Despite rapid increases in population size throughout the Caribbean, including The Bahamas, during initial colonisation, population sizes seem to have stabilised more recently. The impacts of lionfish on non-native reef systems have led to greater awareness of the potential impact of invasive species and tighter controls on those industries that may accidentally introduce new species to the marine environment.

“Lionfish are voracious predators with a diverse diet that includes small fish and invertebrates. They have few natural predators in their non-native range.”
Image: A lionfish hovers above a reef. Threats to coral reefs


The Red Sea is a source of wealth for the eight countries that surround it. Its coastal communities are dependent on the maintenance of a healthy coral reef ecosystem.

Image: A bountiful reef in the Red Sea. the
Coral Reefs: Challenges and Conservation in the Caribbean and
Red Sea
Turning the Tide in The Red Sea

As a rich and highly diverse sea, the Red Sea offers considerable opportunities for prosperity, but is simultaneously under threat from global climate change as well as shore and marine-associated human activities. The eight countries bordering the Red Sea have a relatively low carbon footprint and a smaller-than-most influence on global carbon emissions. When discussing human activity in proximity to the reefs, we should be aware of the global processes occurring in the background. Human activity that directly impacts the marine and coastal environments remains at a low level in global terms (largely due to the lack of access to freely available potable water and arable land over vast areas of the region). There has, though, been considerable growth in the tourism sector, principally promoted on the access to desert and coral reef habitats. This is set to continue and even accelerate as Saudi Arabia enters the sector, dedicating considerable lengths of the eastern Red Sea coastline to tourism-related developments. Gladstone et al (2013) identified the direct impacts of coastal and marine tourism on the environment in the Red Sea, including the Gulf of Aqaba and Gulf of Suez. Primary impacts include local pollution, resource depletion, habitat loss and conversion, and habitat and wildlife disturbance. Indirect impacts originate from support infrastructure, such as the disposal of waste, invasive species, and an increase in human population. Activities undertaken by local inhabitants may also represent additional risks to reefs in the region.

In considering future solutions or actions applicable to the entire Red Sea region, our recommendations can be divided into three main categories:

Coral Reefs: Challenges and Conservation in the Caribbean and the Red Sea



remains in its infancy throughout the region, largely hampered by the absence of a level of scientific knowledge that can confidently inform and support the important decisions required to balance local socioeconomic development with the maintenance of a healthy ecosystem. Some of the information gained on Red Sea coral resilience is likely to be of crucial significance globally. The region is known to harbour corals with a particularly high level of thermotolerance. The increasing urgency to understand the implications of, and take action on, climate change must include a full appraisal of naturally resilient habitats and species. We must do this in order to gain a fuller understanding of their protection mechanism and how it might influence marine community adjustment to the predicted change (Grottoli et al, 2017).

- WHILE RED SEA CORALS may have developed a natural defence against climate change, they remain highly vulnerable to local anthropogenic impacts. Measures are required to minimise local disturbance and remove all hazards so that these reefs endure for generations. An increasingly common tool being used to achieve this is local or national legislative instruments to establish new or extend the boundaries of pre-existing marine protected areas (MPAs). Future and ongoing development, however, is likely to challenge the integrity of these areas, with runoff and discharges from development projects outside of protected areas breaching MPA boundaries under the uncontrolled influence of weather or tide. A greater emphasis on predictive technology (GIS, modelling

etc.) is needed, together with innovative, scienceled spatial management so that potential impacts can be identified and managed as part of an integrated approach. Conservation management should be held to an international standard, together with anthropogenic activity. This should be further supported, fully financed, and effectively enforced with a long-term strategy that includes clear goals and built-in educational opportunities and aspirations.

- UNCONTROLLED AND UNREGULATED artisanal fishing is widespread throughout the Red Sea and overfishing is rampant. Regulatory controls at local and national levels are urgently required to protect the ecological integrity of Red Sea coral reefs. As in many other parts of the world, the controls should monitor and regulate fishing catch rates, in particular during the reproductive season of key fish species. It has been recommended that no fishing be allowed over coral reefs, as an effective no-take zone approach, applicable to both recreational (spearfishing is to be banned) and commercial and artisanal fisheries.

- A CORAL REPOSITORY should be considered in the form of local and regional coral nurseries to preserve essential local genotypes and local coral species (primarily endemic, rare, and/or endangered species). Some reef species are highly dependent on the existence of other species, so where appropriate, propagating an endemic key species may mean securing one or more (sometimes many) other species (Fine et al., 2019).

“The eight countries bordering the Red Sea currently have a relatively low carbon footprint and a smallerthan-most influence on global carbon emissions.”
the Tide in
The Red Sea
Image: Restoration projects enable scientists to grow and plant healthy corals on struggling reefs.



MANAGEMENT: the northern Red Sea has become a hub for tourism, and it is predicted that other Red Sea regions are to follow the same trend. As such, it is in the interest of all the bordering nations to develop a region-wide approach to environmental sustainability. The tourism operators could then establish a Red Sea, or countrywide, sustainability charter that they would need to adhere to, with a strict requirement to demonstrate how they meet a set of agreed criteria.


FOR BUILDING A SOCIOECONOMIC DATABASE: a centralised coordination centre is required to initiate and support greater consistency and harmonisation in Red Sea monitoring programs, while also advancing the implementation of conservation policies.

- EDUCATION: efforts should be made to put into place targeted educational programs. These should be designed to inform local communities of the worth of coral reef ecosystems in the context of their own particular cultural, economic, and ecological values. These programs should also provide advice and guidance on community-led action or initiatives that encourages ownership and stewardship of the measures that can improve or restore habitats within their locality. A component of this could be the establishment of “Citizen Science” projects, where local people are encouraged to undertake monitoring tasks that contribute useful data and track the health of local coral reef habitats. Tour operators should also

educate tourists about threats and unique wildlife. Close cooperation between residents and visitors may help prevent reef degradation.

- CAPACITY BUILDING: while countries bordering the Red Sea rely on many of its services, opportunities should be created that incentivise individuals who choose a career in Marine Science.

- BUSINESS OPPORTUNITIES ON REEF RESOURCES (BLUE TECHNOLOGY): identify and develop the sustainable use of Red Sea bioactive materials from reef organisms as novel tradable goods and services (Rinkevich, 2015).

- A MORE SUSTAINABLE TOURISM APPROACH: countries should rely more on tourism quality than quantity, and the private sector should pay attention to the protection of the reefs when large-scale projects are undertaken. Hasler and Ott (2008) proposed limiting the number of divers on an annual basis as a means of maintaining a more sustainable approach to recreational diving activity. As in many other parts of the world where recreational diving is undertaken around coral habitat, commercial operations should be required to ensure that employed dive guides and instructors have undergone mandatory instruction on environmental awareness and acceptable conduct when diving around coral reefs. This would include a requirement to cover conservation issues in all dive briefings before entering the water.

Image: A healthy Red Sea reef. Coral Reefs: Challenges and Conservation in the Caribbean and the Red Sea
“Efforts should be made to put into place targeted educational programmes. These should be designed to inform local communities of the worth of coral reef ecosystems.”


Introducing a ban to sell sunscreens (with oxybenzone and octinoxate) around the Red Sea coast to try and protect its coral reefs is recommended. Similar bans have been introduced in Hawaii, Palau and some areas of Mexico. In Palau the ban has gone further to include parabens and triclosan.

the Tide in The Red Sea


The Caribbean, including The Bahamas, encounters similar threats as those outlined in the Red Sea, emphasising the need to increase awareness about the various challenges facing coral reefs in the region.

Image: A vibrant and healthy Caribbean reef.
in the Caribbean and the Red Sea
Coral Reefs: Challenges
and Conservation
The Caribbean
The Bahamas
Image: Healthy reefs are a haven for marine life. Coral Reefs: Challenges and Conservation in the Caribbean and the Red Sea

The Caribbean, including The Bahamas, encounters similar threats as those outlined in the Red Sea, emphasising the need to increase awareness about the various challenges facing coral reefs in the region. Additionally, the heightened climate vulnerability of the area further emphasises the urgency of conservation measures. Without prompt action, the future of coral reefs in the Caribbean becomes uncertain. It is evident that a variety of conservation strategies, including restoration efforts, are imperative to maximise the region’s chances of surviving over the coming decades until a point where society realises the reversal of climate change. Furthermore, the region faces unique challenges like the extremely damaging stony coral tissue loss disease, which is impacting reefs throughout the entire region. Such diseases know no international boundaries and requires a coordinated and integrated international effort to irradicate or at least get under control.

A crucial requirement within the Caribbean, as in several other regions, is the establishment of a coordinated and collaborative approach among countries, involving the sharing of knowledge, expertise, and conservation resources. Given the interconnected nature of ecosystems, particularly in the Caribbean region, the well-being and biodiversity of reef systems within one country’s Exclusive Economic Zone (EEZ) will undoubtedly

impact neighbouring countries. Moreover, the availability of resources for conservation efforts and the underlying scientific support varies significantly. A regional approach that harnesses collective expertise and aims to achieve shared goals is essential for the protection and development of diverse and resilient reef systems.

One of the major concerns in the Caribbean is the fact that relatively few species fulfill key ecological roles and thus the impact of losing just a few species can have major consequences for ecosystem functionality. Compared to the IndoPacific region, including the Red Sea, the Caribbean region and the entire Atlantic reef system exhibit lower levels of biodiversity. Consequently, there are fewer species fulfilling specific roles within the broader ecological system. As a result, the loss of even a small number of species can significantly diminish ecological functionality, leading to substantial repercussions throughout the entire ecosystem. In ecological theory this process is called functional redundancy. In general, reefs in the Western Atlantic, which includes The Bahamas and wider Caribbean, have much lower functional redundancy than other regions of the world. The region cannot afford to lose species and strong conservation action is required to compensate for the relatively low functional redundancy. However, many reef systems, including throughout The

Bahamas, have been devastated by the numerous factors explained throughout this report. The need to prioritise reef protection is as important here as anywhere in the world.

“One of the major concerns in the Caribbean is the fact that relatively few species fulfill key ecological roles and thus the impact of losing just a few species can have major consequences for ecosystem functionality.”
the Tide in The CaribbeanThe Bahamas
“The region certainly needs brave new initiatives and funding of those initiatives to ensure the future of coral reefs.”

There are glimmers of hope, particularly for specific countries and projects. Conservationorientated organisations must learn from the best practices and work together with diverse as well as likeminded partners to provide a better chance that reefs in the region will survive the coming decades.

There are numerous conservation projects and actors working within the region to:

- establish stronger and more strategic regionwide Marine Protect Areas,

- develop meaningful sustainable fisheries policies,

- standardise coral reef monitoring procedures and reporting,

- raise greater environmental awareness of the key importance and issues facing Caribbean reefs,

- establish stronger international and national collaborations that are more appropriate within a setting where the health and diversity of reefs of one nation ultimately impact on the health of reefs in heavily connected neighbouring countries.

Despite some real success stories, including on multinational collaborative projects, the region certainly needs brave new initiatives and funding of those initiatives to ensure the future of coral reefs in the region that underpin the economic and food security of so many interconnected nations. Additionally, proactive and pragmatic support from Government is essential in creating a more progressive, solution-based culture in any collaborative efforts to address the critical issues and to mitigate future losses.

For decades we have extensively documented the decline of reef systems in the region and dedicated significant efforts to identify the underlying causes. Now, our focus must shift towards implementing potential solutions to these challenges. It is vital to widely disseminate both the successes and failures of these initiatives to ensure progress and avoid repeating past mistakes. Additionally, we should strive to prevent redundancy in research and studies by building upon existing knowledge. A collective and integrated solutions-based approach

is imperative to effectively conserve the reefs in this region. It is crucial to emphasise that these efforts should be accompanied by global actions to mitigate climate change. Only through such global measures can we restore our planet to a state capable of sustaining essential ecological systems that society and countless species depend upon.

Image: An octopus moves across a reef. Coral Reefs: Challenges and Conservation in the Caribbean and the Red Sea


Coral reefs are essential for the health of our oceans, but their future is at risk. Many governments have had difficulties in developing effective solutions to deal with the growing problem. Clearly we stand the best chance of finding a viable solution if we work together with common goals and share expertise and resourceshere the third sector play an important role.

Image: A trio of divers join a vibrant reef scene.
Coral Reefs: Challenges and Conservation in
the Caribbean and
Red Sea
The Role of Non-Profit Organisations in Coral Restoration

It is impossible to save all areas and coral reefs alone. Cooperation amongst different stakeholders (governmental, non-governmental, corporate, and academic) at different levels (international, regional, national, and local) is needed.

The approach needs to be multidisciplinary, combining conservation, policy and regulations, education, communication and awareness, livelihoods, and production. Noteworthy on this topic is the International Union for the Conservation of Nature (IUCN), a leading group in this field and a unique institution that connects governments and civil society. The organisation has one purpose: “to advance sustainable development and create a just world that values and conserves nature”.

To achieve this, in 2002 the IUCN launched the Global Marine Program, with the goal of protecting

“The path to re-establish coral health globally is long but NGOs, associations and foundations will continue to play a major role.”

or restoring the most resilient ocean and coastal ecosystems, creating benefits for marine life, the communities and their economy (https://www.iucn. org/our-union).

NGOs play different roles in the marine conservation sector. They provide scientific inputs, directly manage projects, offer protection, prevent illegal activities, and empower stakeholders by providing resources, skills and connections (Crosman, 2013). To do that they organise conventions, educational programs, they build marine research laboratories focused on coral conservation, and they organise field trips and communicate their messages using diverse and effective platforms.

Environmental NGOs often have a double role when it comes to making a difference and work across different political, educational and

scientific levels. Their role is to make research and intervention possible but at the same maintain relationships with local communities through education and outreach to ensure stakeholder needs are met.

To meet prescribed goals, a flexible and adaptable approach is essential (Cadman et al 2020). Some achievements have been reached within the field due to direct interventions of non-profit organisations. The path to re-establish coral health globally is long but NGOs, associations and foundations will continue to play a major role in achieving conservation successes.

Image: A coral nursery full of staghorn corals being maintained Coral Reefs: Challenges and Conservation in the Caribbean and the Red Sea
The Role of Non-Profit Organisations in Coral Restoration


The MSC Foundation focuses on implementing direct conservation action aimed at protecting and restoring critical habitats specifically within the Caribbean Sea, in the waters surrounding Ocean Cay. It uses this initiative as an exemplar of what can be achieved through public-private and conservation partnerships. The knowledge gained from these projects should be shared and utilised to support similar endeavours in other areas. It is only through collaboration and meaningful partnerships, driven by a sense of urgency, that we can effectively safeguard the reefs in the region. Time is of the essence, and we cannot delay any longer in identifying and implementing robust conservation solutions to address the multitude of challenges facing Caribbean reefs and reefs worldwide.

Image: A Caribbean spiny lobster hides under a ledge on a coral reef off Cabo Rojo, Puerto Rico. Coral Reefs: Challenges and Conservation in the Caribbean and the Red Sea

On land, Ocean Cay has been completely transformed in to a flourishing and biodiverse environment. This was achieved by planting 4,600 trees and palms, and 75,000 plants and shrubs, across the island. In the marine environment, the MSC Foundation and its collaborators’ approach combines protection, management, and direct intervention utilising state-of-the-art restoration techniques, to rebuild resilient ecosystems. Specifically, the MSC Foundation aims to identify coral species and genotypes that exhibit enhanced tolerance to the environmental threats affecting reefs in the area. These threats primarily stem from the escalating thermal stress caused by ocean warming, as well as the heightened frequency and severity of marine heatwaves. By focusing on selecting resilient coral species and genotypes, the MSC Foundation strives to mitigate the detrimental impacts of these climate stressors on the reef’s long-term survival.

During the initial phases to regenerate the marine environment, a team of marine biologists surveyed all the key habitats around the island and identified areas of coral reef conservation and restoration priority, before carefully rescuing and relocating hard coral colonies from industrial debris that had been discarded on the ocean floor. These actions fostered the longer-term vision of encouraging coral to grow and repopulate existing, yet heavily degraded, reefs. But more was needed and according to marine experts, the key to reversing the rapid decline in coral reefs in such a way that they will survive future environmental change, includes protecting the environment, and sustainably managing that environment to ensure the system is not impacted by local threats.

Thus, a dual approach was devised to provide the conditions where natural recovery processes would maximise the reestablishment of species and genetic diversity combined with a more aggressive approach to establish new populations of thermally resilient corals in areas where natural recovery potential had been lost. The marine conservation program at Ocean Cay will therefore focus on identifying coral species (and specific coral genotypes) that demonstrate thermal tolerance through a combination of approaches including the testing of coral genotype thermal stress responses and facilitating the development of new genetic diversity. The search is therefore on to find these “Super Corals” whilst also providing the right conditions for the reestablishment of system-wide biodiversity and, ultimately, ecological functionality.

To directly advance this work, the MSC Foundation strives to establish a new research facility on Ocean Cay focused on the identification of Super Corals, which, once identified, could be propagated within offshore coral nurseries, alongside other coral species that are critically endangered in the waters off Ocean Cay. The MSC Foundation approach also includes the promotion of environmental awareness amongst its many thousands of weekly visitors, and education through collaboration with Bahamian education and research institutions as well as Florida-based universities by supporting graduate student internships and field-based education experiences. Interns at Ocean Cay will be actively involved with the production of high quality and highly engaging educational material that will be used to inform MSC guests on the importance, threats and urgent need to conserve our blue planet’s coral reefs.

The Role of Non-Profit Organisations in Coral Restoration
Challenges and Conservation in the Caribbean and the Red Sea
Coral Reefs:


Ba’a Foundation is dedicated to creating positive change in both the environment and culture.

Established in 2020, the Ba’a Foundation is a young organisation taking bold leaps forward to inspire, encourage, and develop a strong sustainable ecosystem, driven by cultural development, and brought to life through environmentally conscious practices and initiatives.

Ba’a Foundation initiated the Red Sea conservation program “Reef Revive” that focuses on ensuring a sustainable future for the region’s marine life. One of its main initiatives is to revive damaged coral reefs. This five-year initiative will be developed in three phases (see below). The first phase will focus on immediate coral reef intervention at Jeddah, Saudi Arabia. During initial surveys, the Foundation found a reef in north-west Jeddah, on which hard corals had been deeply impacted by boat anchors and spearfishing. It is also highly likely that the reef has been impacted by climate change related coral bleaching and other possible impacts. A high percentage of the hard corals have died. Live cover on the reef appears to be dominated by soft corals, living along side ascidians, sponges, and turf algae. This is a proof-of-concept project.

From there, the initiative will scale up with the vision to become the largest coral reef revival program in the world. Initiatives aim to mitigate the direct human impact and risks of climate change to coral reefs, using scientific-based international best practices while also encouraging stewardship through engaging and training local stakeholders.

The Role of Non-Profit Organisations in Coral Restoration Image: Anthias are common on Red Sea reefs.
“A longer-term goal will be to share knowledge ... with the wider scientific community and decision-makers around the world.”
Coral Reefs: Challenges and Conservation in the Caribbean and the Red Sea


Ba’a Foundation and MSC Foundation joined forces to advance coral conservation and help safeguard marine ecosystems. Sharing a common goal to protect and preserve the ocean, the two foundations are coming together to advance the practice and science of coral reef restoration and, most importantly, to bring the knowledge they acquire to a global audience. The partnership aims to further the scientific understanding of the best practices for functional restoration of resilient coral reefs and increase the area of reef habitat actively restored. The partnership focuses on specific locations in the Caribbean and the Red Sea where restoration efforts are especially needed.

In the first phase of this partnership, a series of scientific virtual meetings were held with the goal of sharing knowledge and expertise to define targeted areas for collaboration across regions. A longer-term goal will be to share knowledge and results with the wider scientific community and decision-makers around the world as well as the guests who visit these destinations.

The Role of Non-Profit Organisations in Coral Restoration Image: A bommie adorned with coral.

In the Red Sea, the Jeddah Coral Reef Restoration Project has three main tasks:

1. CORAL RESTORATION. This task aims to establish baseline surveys to develop a coral restoration strategy. Marine ecological surveys are required to assess the viability of the Jeddah coral reef site and to inform the detailed planning of coral restoration activities. The data collected through the baseline survey and studies will be used to prepare a Coral Restoration Plan, which will provide specific details about the coral gardening strategies and methods to be employed by the project. It is proposed for coral reefs to be donor sites for coral nurseries that will allow planting out of corals, this is termed coral gardening. The coral fragments from the ‘garden’ will be placed on a degraded coral reef to restore it. Monitoring will take place to measure the performance of these gardening efforts.


Mooring buoys will be installed around the restoration site to protect the reef from physical damage caused by repeated wild anchoring. This site will be checked regularly to ensure success of the restoration project. This will complement the Coral Restoration Plan.

3. AWARENESS AND EDUCATION. This task of the project focuses on education and raising awareness about coral reefs, their importance, the key threats, and the types of actions that can be taken to help address the threats. There will be a social marketing campaign using images from the site to be restored. This is also to gain ongoing

sponsorship to support the restoration efforts of the Jeddah Reefs.

In the Bahamas, the MSC Foundation’s Super Coral Programme is taking a similar approach and bases its activities on three main pillars:


Initial surveys have explored the marine biodiversity of the 64-square mile area surrounding Ocean Cay. These surveys identified key habitat types, species abundance, diversity and richness and areas where significant environmental degradation has occurred. The baseline surveys identified missing foundational coral species, and degraded reefs with limited natural recovery potential. Data from these surveys were used to identify priority areas to action for restoration. Coral restoration strategies will target species that are absent from the surrounding waters, but where research from adjacent reef systems suggest they should be present or historical records identified they were once present. When putting these species back in to the environment, populations that have demonstrable thermal resilience will be preferentially used. Therefore, the program not only aims to protect and conserve natural biodiversity, but aims to regenerate climateresilient coral populations to ensure the long term functionality of coral reefs in the region.


The MSC Foundation program aims to advance applied coral research training and support the next generation of marine

biologists directly through offering graduate internship opportunities as well as direct educational experience for groups visiting the island. Within these programs, interns and visitors will gain a much better understanding of the ecology of coral reefs and the urgent need for their protection. Furthermore, guests, visitors and students will specifically learn about conservation action including restoration approaches and, in some cases, will be actively engaged with direct conservation action. These will offer unique opportunities for interns and educational visitors to engage with marine experts and applied conservation practitioners. Additionally, it will help company employees who have direct responsibility for raising environmental awareness of guests and managing the fragile resources of this island. It is hoped this programme will deliver well-informed graduates with the potential to go on and become professional marine scientists and conservations or citizens that get involved with the sustainable tourism sector to protect and educate the wider world on the plight of coral reefs and the urgent actions needed to conserve our blue planet for future generations.


Perhaps the most unique opportunity offered by Ocean Cay and the direct involvement of the MSC group is the potential for MSC Foundation staff, collaborators, and interns to directly engage with the many thousands of individuals who are guests to the Cay through MSC Cruises. This offers a unique opportunity for conservation actions and issues of environmental change to be directly

Coral Reefs: Challenges and Conservation in the Caribbean and the Red Sea

delivered, in a highly engaging manner, to an audience who otherwise may not have opportunities to learn from practitioners and witness results directly. As well as on Ocean Cay, the MSC Foundation have dedicated spaces on many of its cruise ships which can be used as a platform to raise awareness of the conservation issues impacting our blue planet. This direct line of engagement extends from on-the-ground activities to targeted education and awareness programs conducted onboard ships, reaching a highly engaged audience. The Foundation’s reach spans hundreds of thousands of individuals, making it a powerful platform to convey the narrative of marine environmental impact, highlight the future trajectory of our planet’s marine resources, and shed light on the collective efforts aimed at safeguarding our precious marine systems from future harm. Through direct engagement, this initiative effectively reaches an audience that may otherwise be unaware of the challenges faced by our blue planet.

Image: A turtle settles on the sand between coral outcrops.


To make a sustainable and permanent change towards the conservation and restoration of coral reefs, everyone should pay attention to their actions. Here are a few simple steps that anyone can either adopt or implement to take care of coral reefs and the health of the ocean:

in the Caribbean and the Red Sea
Coral Reefs: Challenges and Conservation


Any kind of litter pollutes the sea and can harm coral reefs. Reduce your waste and always ask yourself: do I need to buy this? Recycle your rubbish at home and on-the-go in waste bins. Watch out that no litter is blown into the sea or into rivers that end up in the sea. Never leave behind litter on beaches and never throw away your cigarette butts as they are made of plastic. Contribute to beach cleans or litter picks near you:

become an Ocean Ambassador


Is your tour operator environmentally responsible? Choose a responsible tour operator, ask if they play a positive and active role in ensuring marine life thrives. Do they donate to a local charity or marine life organisation or otherwise engage with conservation activities. Do they have a responsible tour operator charter? Listen to the briefing by your tour operator, ask questions. Help spot marine life and key species such as the Crown of Thorns starfish. Ask if you can help with any monitoring of ecologically significant species:

become an Ocean Educator


Research where your seafood is from; does it come from the reef you snorkelled this morning? Be aware of the origins of the seafood you’re eating and whether it was fished sustainably. You should never eat parrotfish, sharks or rays:

become an Ocean Advocate


Try to bike, walk or use public transport more often. If you have a car, buy a fuelefficient or electric vehicle. Anything that lowers the carbon emission from your vehicle. If you are able, off-set your holiday flight emissions when you travel to see coral reefs:

become Ocean Aware


Engage with the key issues and learn more so that you can actively contribute to educate your community about the importance of coral reefs and the dangers of its destruction. Be sure to focus on stories of hope and opportunity to show that there is a future for our coral reefs and our blue planet:

become an Ocean Optimist


Never take from the sea or buy from merchants anything that has been taken from the sea, including wildlife such as coral, parrotfish, sea cucumbers, turtles, sea horses or ornamental fishes. If you own a marine aquarium avoid purchasing living coral and make sure the fishes have been collected in a sustainable way:

become an Ocean Conservationist


Oxybenzone and octinoxate are common ingredients in sunscreens which are toxic to corals. Sunscreens that use non-nano zinc or titanium oxide as their active ingredients do not contribute to coral bleaching. When in the water, wear a longsleeved rash vest or full body swimsuit to limit your exposure to the sun as it damages your skin:

become an Ocean Protector


Coral reefs are very delicate, and every contact can potentially damage them. Be careful when diving and snorkelling and avoid touching or damaging reefs with fins, fishing equipment or anchors:

become an Ocean Guardian




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