A Discussion on Problems Faced by Leatherback Sea Turtles and Development by SOS Tobago

NOTTINGHAM TRENT UNIVERSITY

A DISCUSSION ON THE PROBLEMS GIANT LEATHERBACK TURTLES FACE AND WHETHER DEVELOPMENT AFFECTED THE NUMBER OF CONFIRMED LAYS IN 2008 ON TOBAGO

Owen C Hibben

Dissertation submitted in partial fulfilment of the BSc (Honours) Degree in Wildlife Conservation

2011

Abstract The Giant Leatherback Turtle (Dermochelys coriacea) is listed as “critically endangered” by the IUCN (2011). It has been reported to be in rapid decline all over the world over the past few decades. The main cause of this rapid decline is “man”. Harmful fishing techniques, egg harvesting and litter are just a few of the problems that the Leatherbacks face. However, there are suggestions that Leatherback populations outside the Pacific may be stabilising or increasing (Hughes, 1996; Dutton et al 2005). This could be down to a better understanding of the species, locally and internationally, due to more education and more advanced conservation techniques. One problem that is rarely investigated is whether the presence of humans on or around tourist beaches, where the turtles themselves nest, has a detrimental impact on populations. This study will investigate two beaches, one with development and one without, to see whether there is any significant difference between nest numbers on a developed and secluded beach. Although most people would think that most turtles would nest on a secluded beach there was significant (p – value= 0.056 & F₁,₇=5.599) difference between the two beaches in the 2008 nesting season. Further investigation in to this could help SOS Tobago develop new conservation strategies and keep on increasing their nesting populations.

Acknowledgements I would firstly like to thank Giancarlo Lalsingh for allowing me to work for SOS Tobago in my industry year and for the 2008 nesting data that he supplied me with. I would also like to thank Peter Cox, of Tobago Wildlife Tours, for getting me interested in Wildlife Conservation from an early age and to my parents Chris and Jane Hibben for nursing this interest of mine. Thank you to Dr. Nicholas Ray for his guidance as my dissertation supervisor and Anna Champneys for her support as my tutor. I would also like to thank Rebekah Long for her general support.

Table of Contents Abstract.............................................................................................................................................I Acknowledgements..........................................................................................................................II Table of Contents............................................................................................................................III List of Figures..................................................................................................................................VI List of Tables...................................................................................................................................VII Chapter 1 1.0 Introduction 1.0.1

Background information.........................................................................................1

1.0.2

Problems facing Tobagoâ&#x20AC;&#x2122;s nesting population........................................................1

1.0.3

Declining population worldwide............................................................................2

1.0.4

Two key nesting beaches on Tobago: Turtle Beach (TB) and Back Bay (BB)..........3

1.1 Problems and issues 1.1.1

Development and artificial lighting........................................................................4

1.1.2

Climate change, rainfall and temperature changes...............................................6

1.1.3

Poaching and harvesting........................................................................................8

1.1.4

Effects of fisheries and litter on and off beaches...................................................9

1.1.5

Increased risk of predation...................................................................................11

1.2 Preventative measures 1.2.1

Education and culture..........................................................................................12

1.2.2

Law and legislation...............................................................................................14

1.2.3

Present conservation strategies...........................................................................15

1.3 Aims and hypothesis.......................................................................................................17 1.3.1

Null hypothesis (H0).............................................................................................18

1.3.2

Alternative hypothesis (H1)..................................................................................18

III

Chapter 2 2.0 Method and materials 2.0.1 Location of study......................................................................................................19 2.0.2 Study sites 2.0.2.1 Turtle Beach..............................................................................................19 2.0.2.2 Back Bay Mt Irvine....................................................................................20 2.0.3 Data collection method............................................................................................20 2.0.4 Data analysis method...............................................................................................21

Chapter 3 3.0 Results 3.0.1 Differences in CL numbers........................................................................................22 3.0.2 Nesting pattern for the 2008 nesting season...........................................................22 3.0.3 Distributions across TB and BB.................................................................................23 3.0.4 Significance between the two beaches....................................................................26

Chapter 4 4.0 Discussion 4.0.1 Analysis of findings and results................................................................................28 4.0.2 Limitations to the study............................................................................................29 4.0.3 Recommendations for future research and conservation........................................31

Chapter 5 5.0 Conclusion 5.0.1 Summary and evaluation..........................................................................................34

References......................................................................................................................................36 Appendix I: SPSS output.................................................................................................................43 Appendix II: Raw data.....................................................................................................................45

List of Figures

Figure 1.0: a bar chart showing the decline in Leatherback numbers from 1988-2007 in the Pacific. Source: Las Baulas National Park, Costa Rica. 2011

Figure 1.1: index Beach Nesting Totals of Leatherback nesting events 2000-2007. Source: SOS Tobago 2007

Figure 1.2: this image of two turtle shells shows that poaching activity is still apparent on the island. Image was taken on L’Anse Fourmi located in the north of Tobago. © Owen Hibben 2010

Figure1.3: a beach cleanup carried out by SOS Tobago in 2010. ©Pippijn Bus 2010 Figure 1.4: an educational talk at a school close to the capital, Scarborough in Tobago. © Owen Hibben 2010

Figure 2.0: satellite image of Turtle Beach, Tobago. Source: © Google Imagery 2011 Figure 2.1: satellite image of Back Bay, Tobago. Source: © Google Imagery 2011 Figure 3.0: line graph representing the number of confirmed lays (CL) on both TB and BB for the 2008 nesting season. Source: SOS Tobago 2011

Figure 3.1: boxplot showing the mean, range, upper and lower quartiles of confirmed lays on both beaches. Source: SPSS v. 18 2011

Figure 3.2: a histogram showing frequency of confirmed lays on Beach A (TB). The normal distribution curve shows that data is normally distributed. Source: SPSS v. 18 2011

Figure 3.3: a histogram showing frequency of confirmed lays on Beach B (BB). The normal distribution curve shows that data is normally distributed. Source: SPSS v. 18 2011

Figure 3.4: a normal Q-Q plot of confirmed lays on Beach A = TB. Source: SPSS v.18 Figure 3.5: a normal Q-Q plot of confirmed lays on Beach B = BB. Source: SPSS v.18 Figure 3.6: a bar chart illustrating the amount of confirmed lays (CL’s) on both beaches (TB and BB) for the 2008 nesting season. Source: SOS Tobago 2011

Figure 3.7: mean number of CL’s per beach and their individual standard errors. Source: Microsoft Excel 2011.

List of Tables Table 3.0: shows the amount of CL’s 2008 nesting season on Turtle Beach. Source: SOS Tobago 2011

Table 3.1: shows the amount of CL’s 2008 nesting season on Back Bay. Source: SOS Tobago 2011

VII

A discussion on the problems Giant Leatherback Turtles face and whether development affected the amount of confirmed lays in 2008 on Tobago 1.0 Introduction 1.0.1 Background information The Giant Leatherback Turtle, the largest marine turtle in the world, is seen as “critically endangered” according to the IUCN Red List (2011). It has the largest migration routes of any marine turtle and has been reported to travel thousands of miles across vast oceans following their prey source and swimming against very strong currents (Sea Turtle Conservancy, 1996 – 2011). The great size of their home ranges mean they are at high risk of coming in to contact with many different dangers. Each female will nest between 7 to 10 times in a season laying between 80 – 150 eggs each time; they will nest every 2 – 3 years. The Leatherbacks have the lowest average hatching success rate of any marine turtle, usually between 40-60% (Miller, 1997), which again is detrimental to their survival. Their nesting numbers have dropped dramatically in recent decades due to factors such as; trawler nets, litter at sea, poaching, disturbances to nest sites, climate change and destruction of nesting beaches. It is difficult however to measure the effect these factors are having on all nesting females on Tobago as individuals do not nest every year. Long-running studies would be necessary if the impact is to be assessed more thoroughly over time. 1.0.2 Problems facing Tobago’s nesting population Tobago relies heavily on tourism to fuel its economy, which in turn creates a great deal of demand for hotels and other beach side resorts. This then creates a bigger potential for artificial lighting, litter entering the sea and sand, beaches reducing in size and compaction of sand due to high numbers of people and machinery. Another problem Tobago faces is the number of cars

and other vehicles that drive along the beach, due to lack of other authority and barriers to stop them. However, if tourism is guided and dealt with in the right way, ecotourism can be beneficial to local communities and the conservation of the species: as evidenced by the impact of the controls and restrictions in place on Grande Riviere and Matura beach in Trinidad. Grande Riviere is seen as one of the most densely nested Leatherback beaches in the world. It has two hotels on the beach that take preventative measures to ensure their existence does not affect the turtles nesting habits and hatchlings (SEE Turtles, 2007 â&#x20AC;&#x201C; 2011), as their main income is from the thousands of tourists who come to see this amazing species. 1.0.3 Declining population Rapid decline in nesting activity has already been witnessed on nesting beaches in the Pacific. SuĂĄrez & Starbird (1996) found that the Leatherback population was in rapid decline around the islands of Kai, in the Pacific. Predation of nests, poaching and erosion were key factors in their decline, but hunting of nesting adults probably had the biggest impact. Since then estimates in the Pacific show >90% decline in nesting females (ToĂŤng et al, 2004; Schillinger et al, 2008; Witt et al, 2009). It is assumed that the majority of mortalities in adult turtles are due to gill net and oceanic long-line fisheries (Eckert & Sarti, 1997; Spotila et al, 2000). Conservation International (2011) illustrates these declines in Figure 1.0:

Figure 1.0: Decline in Leatherback numbers from 1988-2007 in the Pacific. Source: Las Baulas National Park, Costa Rica. 2011

The decline of Leatherback numbers worldwide predominantly reflects the decline of the Pacific populations. So in order to understand trends in the wider population more studies need to focus on modelling the Atlantic/Caribbean populations and whether their numbers are in decline too (ToĂŤng et al, 2004). There is, for example, a question mark over the appropriateness of the â&#x20AC;&#x153;Critically Endangeredâ&#x20AC;? label for the overall population as Dutton et al (2005) stated that population numbers outside the Pacific were reported to be stable or increasing. This can also be supported by figures recorded by SOS-Tobago from 2000-2007, as shown here in Figure 1.1, which shows that nesting events have been fairly stable from 2001 -2007. Sarti Martinez (2000) also indicated that some small Caribbean populations are increasing, although this is insignificant compared to the level of decline in other parts of the world.

Figure 1.1: Index Beach Nesting Totals of Leatherback nesting events 2000-2007. Source: SOS Tobago 2007.

1.0.4 Two key nesting beaches on Tobago: Turtle Beach (TB) and Back Bay (BB) TB is a mile long stretch of beach. The beach itself has a number of developments on it, the main one being the Rex Turtle Beach Hotel. A great deal of the beach is lit by artificial lighting and this issue has always been seen as a concern for adult and hatchling disorientation. BB is a secluded beach just down the coast from TB. The beach itself is separated into three different sections by rocky outcrops and has no developments on it as yet. BB has no issues with 3

artificial lighting but is at a higher risk from illegal activities such as poaching due to it being so secluded. 1.1 Problems and Issues 1.1.1 Development and artificial lighting The Leatherback Trust (2011) believes that humans are the main reason why the Leatherback is in decline. Each year, worldwide, acres of nesting beach are lost due to developments such as hotels and private residences causing sand erosion and squeezing of the beaches. On Tobago, TB has a great deal of development on it. In recent years more private properties have sprung up along the beach. In some areas the developments themselves have severely displaced sand and changed the layout of the beach. One property in particular has had to rebuild its beach side wall as it collapsed into the sand. This meant old rusting building materials littered parts of the beach which could be a problem to adult and hatchling turtles. The increase in properties also means an increase in light pollution across the beach. There is a worldwide problem with light pollution on nesting beaches. They are usually more of a problem for hatchling turtles but can also cause a problem for nesting turtles. Turtles are very sensitive to light and use it as their navigational system. The more artificial light on the beach the more disorientated some turtles become when either trying to find a nesting site or return to the sea. So you would expect higher nesting frequencies on lesser developed or secluded beaches, similar to BB on Tobago due to the lower levels of light pollution (Witherington, 1992; Witherington & Martin, 1996; Salmon 2002). TB suffers a great deal from problems with artificial lighting due to the fishery lights, hotel lights, street lights and private property lighting. Whereas BB has no artificial light, which means there is less chance for turtles to become disorientated. Hatchlings are also very sensitive to light, so

artificial lights interfere with the natural cues and can cause them to go in land rather than out to sea (Bourgeois et al, 2008). Once they venture inland they are susceptible to dehydration, increased predation and problems from human traffic. It is estimated that only 1 in 1000 hatchlings make it to sexual maturity, so SOS Tobago believe it is essential that every hatchling survives to keep the population stable and hopefully help it increase. However, the hotel and street lights make this very difficult on some beaches. This will forever be a constant battle if there is no solution, as it is argued that the lights are needed for security reasons especially around hotels. However, there are ways of providing lighting near nesting beaches that has been proven not to affect nesting females. Salmon (2003) experimented with lights on popular nesting beaches in Florida and found that when lights were â&#x20AC;&#x153;onâ&#x20AC;? nesting activity nearly reduced to zero and when switched off nesting females would return. New ordinances and laws about regulating and restricting light on nesting beaches are being instigated in the U.S. For example in Charlotte County, Florida, a Sea Turtle Protection Ordinance (89-31) has been put in place. It prohibits artificial lighting on nesting beaches (Charlotte Country Government, 2011). Florida has recorded that the nesting numbers are slowly increasing year upon year (Salmon, 2003). The quality of light was also of significance as they found white light repelled the turtles whereas yellow light did not. This could be an effective way of reducing disturbance for nesting turtles for all beach side developments across the globe. Witt et al (2009) identified Gabon, on the West coast of Africa, as the largest Leatherback nesting population. In recent years they have indicated that artificial lighting from cities and towns are causing problems with nesting and hatchling turtles (Deem et al, 2007). In order to help reduce the problem they are facing with artificial light, in Gabon they have started educating the public about the problem and setting up temporary barriers to reduce the impact.

Rondón Médicci et al (2009) interviewed people in Venezuela about whether they think artificial lighting affects turtles and the majority of those interviewed believed that artificial light did not affect any sea turtles. But when they studied whether artificial lighting had an impact on nesting Leatherbacks, they found a significant decrease in the proportions of landings with nest buildings during the years of artificial lighting (p=0.005). However, nesting success did not vary (p=0.402) so although adult emergence decreased with artificial light it did not affect the amount of successful nests compared to years without artificial lighting. 1.1.2 Climate change, rainfall and temperature changes The weather has a big impact on the successful hatching rates of nests. Albino hatchlings that are found during nest excavations are a sign of changes in temperature. Reptile nests generally are very sensitive to temperature changes, and the sex of turtle hatchlings is dependent on the temperature in the nest (Broderick et al, 2001). These changes can come about due to seasonal changes, from dry to wet season, and the impact of weather systems such as El Niño. In the nesting season of 1998-1999 in Costa Rica, Bilinski et al (2001) believed that El Niño and unusually high tides were the reason for high embryonic mortality in the nests. In 2010, Tobago witnessed the driest and hottest dry season in decades, which in turn led to hotter and drier sands. This meant that some turtles were unable to dig far enough down to nest; so many nests were too near the surface and cooked in the heat. Problems like this severely reduce the nest hatching success rates of the Leatherback, which is already quite low. Bell et al (2003) found at Las Baulas, in Costa Rica, between 1990 and 2000 the success rates of hatching nests ranged from 19.2% - 54.2%. He believed these low success rates could be caused by nest mortality and infertility. Nesting hatching success can be due to many reasons such as location of nest on the beach. The topography of the beach can affect whether the nest hatches and if it does hatch it can also affect the orientation of the hatchlings. Mrosovsky (1983)

estimated 40% of nests in the Guianas were poor nest sites due to the topography of the beach. This was due to the belief that Leatherbacks have adopted scatter nesting strategies to ensure the survival of at least one and maybe a few nests. Increased rainfall has also been identified as a reason for high nest and hatchling mortality. Houghton et al (2007) found that increased rainfall had a marked cooling affect on nests and produced more male producing temperatures (<29ºC). This could be a reason why so many nests during the changing of the seasons are unsuccessful. Heavy rain can also lead to beaches being levelled by run-off rain water from drains and the nearby roads. On developed beaches heavy rains can mean rivers can break through and cut away considerable amounts of the beach. This problem doesn’t just wash away already existing nests but it also causes a problem for future nesting turtles. With parts of the beach cut away approaching turtles can get extremely disorientated when unable to climb the steep banks of sand and quickly become exhausted and so try and nest too close to the sea or in the inlets created where streams or rivers have broken through the beach. The effects of heavy rain can be magnified by the proximity of human activity and development. This is supported by the fact that in Tobago, BB is not as badly affected by heavy rain as TB, as there is no development on the beach itself or drains from property leading on to the beach. At Playa Grande, in Costa Rica, it was found that females still nested in areas of beach where, during the rainy season, water from the rainforest creates an inlet in the beach and washes many of the nests away (Nordmoe et al, 2004). This is a natural occurrence. Whereas, on some of Tobago’s beaches, such as Grafton - another developed beach - human waste flow, with at least 8 drains flowing out on to it -from hotels, villas, restaurants and private properties, severely affects the suitability of the beach for nesting. Such is the severity of the impact that drains can have, beaches can become too flat and unsuitable for nesting. In flattening the beach it changes

the high tide line. So some nests are then more susceptible to being soaked and drowned during their incubation and development (Attenborough, 2008). It is also important to stress the significant effects of climate change and rising sea levels on nesting beaches, such as those on Tobago, where turtles may be forced to nest closer to the sea (Caut et al, 2009). If nothing is done to prevent the flattening of beaches, rising sea levels could mean that the rates of successful nests could drop dramatically. If this occurs on Tobago and other surrounding Caribbean islands the Atlantic population could decline dramatically. Scientists have warned that, by the end of the century, sea â&#x20AC;&#x201C; levels could have risen by over one metre (Wildlife Extra, 2008). With development on the beaches and the affects of rising sea levels, the beaches may become too narrow to nest and so beaches with developments are at a higher risk. 1.1.3 Poaching and harvesting Human induced mortality on nesting beaches is fairly frequent on some beaches on Tobago. Activities such as poaching and nest harvesting are more apparent on secluded beaches, such as BB. Whereas on TB poaching has and still remains an issue, it is less marked than on secluded beaches. Poaching and egg collecting is still apparent in Tobago as shown here in Figure 1.2:

Figure 1.2: this image of two turtle shells showsthat poaching activity is still apparent on the island. Image was taken on Lâ&#x20AC;&#x2122;Anse Fourmi located in the north of Tobago. ÂŠ Owen Hibben 2010.

BB is more open to poaching as there is no development or lights on or near the beach. In recent years SOS Tobago workers have come across poachers on the beach. There was even one incident when Jason Ayres (SOS employee) was assaulted whilst trying to protect a turtle (Lalsingh, 2007). Poaching is also still present on Grenada, West Indies. Maison et al (2000) found that on one beach 73% of nests were poached. Poaching and harvesting is a worldwide problem in many countries that are visited by nesting females. It has long been believed that turtle eggs are a good aphrodisiac and this is one of the reasons why the eggs are harvested. Poaching activity usually increases around the time of village harvests. It not only harms nesting turtles and eggs in the nest if taken, it can also deter approaching females from nesting if they feel threatened. In Costa Rica, by 1975, poaching was well established and an estimated 90% of eggs, every nesting season, were harvested. However, since beach protection was introduced in the 1990â&#x20AC;&#x2122;s poaching has been reportedly reduced to <1% a year (Tomillo et al, 2008). Indeed, in some places regular patrolling and further conservation strategies has reduced the likelihood and levels of poaching. In Trinidad, for example, it has been estimated that poaching has been reduced to near zero in a matter of decades (Eckert & Grobois, 2001). It is now believed that the biggest threat to their survival is the effect fisheries are having on adult numbers out to sea. 1.1.4 Effects of fisheries and litter on and off beaches It is believed that fishing activities, such as gillnets, are the main reason for adult turtle mortality (Hays et al, 2003). Lutcavage et al (1997) believed that before protection measures were implemented thousands of adult turtles were killed each year by shrimp trawler nets. This problem is compounded by the fact that it takes Leatherbacks between 20 â&#x20AC;&#x201C; 30 years to reach

sexual maturity, and since only 1 in 1000 hatchlings makes it to adulthood the low rate of successful nest hatchings worldwide stacks the odds against their survival. Fisheries around the world accidentally catch species as a by-product of their activity. When Leatherbacks get caught in gill nets or trawler nets they are unable to return to the surface for air, so most end up drowning if not found in time. It is of great concern that figures about turtle numbers brought up in pelagic and coastal fisheries are largely unknown (Dutton et al, 2005). These high mortality rates really highlight the need for added protection and the need for further research not just on nesting beaches but on their migratory routes as well (Hays et al, 2003). Litter is a significant problem on and off the beaches. The UNEP (2011) believes that marine litter causes so much harm to the ecosystem and its inhabitants due to its slow rate of degradation, for example plastics. It is reported that around 90% of floating litter is plastic (UNEP, 2011), which causes a severe problem as many Leatherbacks mistake it for their main prey source, jellyfish (Scyphozoa spp). The largest Leatherback ever recorded was washed up on a beach in the UK and was found to have a plastic bag lodged in its throat. Some individual turtles have been found to have up to around 5 kg of plastic in their stomachs (National Geographic, 1996-2011). Since 2003 the â&#x20AC;&#x153;Global Initiative on Marine Litterâ&#x20AC;? has been in place to try and help encourage sustainable management and control of marine litter (Chesire et al, 2009), in the worst affected seas around the world, with the Caribbean being one of them. Along with educational talks SOS-Tobago also takes volunteers to do beach clean-ups all over the island. As shown in here Figure 1.3:

Image 1.3: A beach cleanup carried out by SOS Tobago in 2010. ©Pippijn Bus 2010

Every year significant amounts of litter are taken off Tobago’s beaches, ranging from plastic bags and bottles to car tyres and items of clothing. Litter and debris on nesting beaches can deter females from nesting and disorientate both adult and hatchling turtles (Bourgeois et al, 2008). During the nesting season of 2010 debris washed up on many beaches. The debris that washed up on TB was gathered together and burnt on the beach, which would deter nesting females and cook nests nearby in the sand. The Marine Conservation Society (2011) believes that litter on the sand and through the sand column can lead to a reduction in suitable nesting sites. One would think that during the nesting season of a “critically endangered” species, fires would be prohibited by government and the hotel itself, due to the fact that the turtles are one of the main attractions of the island. On TB problems such as sand erosion from private properties and fishing nets and ropes left out on the beach between can cause problems for hatchlings and adult females coming in to nest. Bourgeois et al (2008) studied the impact that objects such as logs had on the beaches. They found that if the object was nearer the sea it had a negative effect on a turtle’s orientation, and this is similar to the problem that fisherman’s nets and other debris cause on TB. 1.1.5 Increase risk of predation Conservation law is effective to a degree in stopping illegal human activity. However, it does not protect the turtles and hatchlings from unnatural predators such as dogs and cats that have been introduced through human development. History has told us that humans have 11

accidentally and purposefully introduced non-native species, and that this can have a severe negative effect on native species. In the Galapagos Islands, stray cats and dogs are the greatest threat to native species due to competition, predation, disease and habitat destruction (Humane Reseach Council, 2009). Tobago faces a similar problem. Tobago itself has a very large number of stray dogs and cats on the island. Dogs especially cause massive problems for nesting and hatchling turtles. Unlike natural predators, that may only take a few hatchlings at one time, such as Ghost Crabs (Ocypode quadrate) or the Yellow Crowned Night Heron (Nycticorax violaceus), stray dogs will take as much as they can eat, which can be very detrimental to the survival of successful nests. They can also pose problems for adult nesting turtles and deter them from nesting on certain beaches. There is a strong case for new laws to help tackle this over-population. More funding for animal health units/centres could also help in neutering and spaying of stray and household cats and dogs, whereas at the moment controlling these populations is done by random poisoning, which could then have an effect on other wildlife species on the island and not just the problem species. 1.2 Preventative measures 1.2.1 Education and culture One aspect that will be very difficult to change on Tobago is that of peopleâ&#x20AC;&#x2122;s cultural views. SOS Tobago has started taking educational talks to schools to try and reach out to the next generation and get them involved in conservation and preservation of the species. Figure 1.4 shows an SOS Tobago educational talk at one of the schools on Tobago.

Figure 1.4: an educational talk at a school close to the capital, Scarborough in Tobago. © Owen Hibben 2010

It is clear to see that the reasons for poaching and egg harvesting are mainly down to traditional views, lack of conservational education and it’s an easy way to make money. But with more education about the Leatherbacks’ situation, it is possible to show people that more money can be made from education and conservation of the species, which in turn will also help the island’s economy. WWF (2011) believe that raising awareness in local communities is one of the best ways of protecting the species. In Tobago, Leatherbacks are still seen as a seasonal delicacy, and this means poaching is still rife on the island (SOS Tobago, 2011). It will always be a problem when it seems easier to make money from poaching and harvesting and this is down to a lack of education. However, promoting eco-tourism and strict turtle watching guidelines on nesting beaches, such as TB and BB, will hopefully reduce poaching and raise awareness of conservation and show the potential economic value of doing so (Lalsingh, 2009). SOS Tobago (2011) hope that by educating local communities about the importance of beach patrols they will be able to implement more effective conservation and management techniques of this critically endangered species and their nesting beaches. This technique has proved very effective in other countries and poaching has been significantly reduced. Lutcavage et al (1996) found that, in Costa Rica, many ex poachers had been educated and trained as turtle guides and now earn their income from conservation. More studies need to be done to determine whether poaching is decreasing on Tobago at all to see whether these strategies are having an effect.

1.2.2 Law and legislation In 2004, the Marine Turtle Conservation Act (MTCA) was introduced in the U.S. to help protect the remaining turtle populations around the world (Donnelly & Possardt, 2004). The act’s aim is to protect and manage nesting populations and their nesting sites, along with future research projects, law enforcement and educational programmes. MTCA was introduced to provide funding to foreign marine turtle conservation projects (WWF, 2011). Its acts like this that could give regular funding to community – based organisations, such SOS Tobago, allowing them to expand their conservation and educational efforts on the island. Laws on turtle protection on Tobago are currently being revised due to the fact they only really offer protection during the nesting season (1st March – 30th September) (SOS – Tobago, 2011). Tobago’s turtles are supposedly protected by 3 laws, they are: 1. Convention on Trade in Endangered Species of Flora and Fauna (CITES) 2. The Trinidad and Tobago Conservation of Wildlife Act – Chapter 67:01 3. Fisheries Act 1975 – Section 4 “Protection of Turtle and Turtle Egg Regulations” Source: SOS Tobago, 2011.

Even though these laws are in place, there is still evidence year in year out of poaching and egg harvesting on many beaches around Tobago. Such illegal activities may not be as frequent on beaches such as TB due to beach side developments and more chance of human interaction, but secluded beaches such as BB have a higher risk of poaching. According to Eckert & Grobois (2001) they are also protected under Annex II of the Protocol of the Cartagena Convention concerning Specially Protected Areas and Wildlife, also known as “SPAW”. They are also protected by the Bonn and Bern Conventions. All this protection is to help convey the message that the conservation of this species and their marine and nesting habitats are of the utmost importance. 14

Passing laws is one thing. Effective enforcement of them is quite another. Despite all the legal protection, there is still a great deal of poaching and harvesting every year. Eckert & Honebrink (1992) found that the harvesting of eggs and the killing of nesting females has severely reduced the once thriving populations in St. Kitts and Nevis. In countries where these activities are rife, there is an argument for stricter punishments to be introduced to deter people from carrying out these illegal activities. On some Caribbean islands, such as Barbados, there are severe punishments for those caught handling turtle products. These punishments range from hefty fines to imprisonment. 1.2.3 Present conservation strategies However, several strategies are being used by conservation groups to help protect nesting populations. SOS Tobago actively relocates nests that are too close to the high tide line or in poorer parts of the beach itself. Dutton et al (2005) believes that increasing early stage survivorship by nest relocation can contribute to future population increases. Dutton et al (2005) believes the increase in nesting populations, in St. Croix since the early 90â&#x20AC;&#x2122;s is due to an aggressive programme of beach protection and nest relocations. These methods were believed to be simple and effective so long as adult mortality out to sea was low. However, there are suggestions that nest relocation significantly reduces the likelihood of the nest hatching. Nest relocation is a widespread management technique that is used worldwide on nesting beaches. However, there are disadvantages to this technique. It is a very delicate procedure and most relocated nests are not that successful. Eckert & Eckert (1990) found that relocated nests reduced hatching success compared with in â&#x20AC;&#x201C; situ nests in St. Croix. Nests are relocated each year on TB due to females nesting too close to the high tide line. If these nests were to be left the eggs would drown as they become swamped at high tide, so even though nest relocations are not that successful, it does give the vulnerable nests another chance.

Those nests that do not hatch for some reason or another are studied by SOS Tobago to investigate why certain nests do not hatch. Studies like this year upon year may help SOS Tobago understand why at certain times of the nesting season nests fail or whether they fail due to human influence. Nests on TB will be more at risk from human activity so it would be interesting to see whether the human activity affects the hatching success. Successful nests are also excavated if they are found. This research allows SOS Tobago to see how successful the successful nests actually are. Data like this provides critical information and helps explain why some areas of beach or some beaches have better success rates than others. It also helps improve conservation techniques and introduce new projects. Tobagoâ&#x20AC;&#x2122;s nesting beaches are all open to the public, which is one of the main problems as there is no control over who can enter the beach. Whereas in Trinidad and Costa Rica visitors have to pay to get on to the most popular nesting beaches, be accompanied by rangers and in some places have passes. This strict method helps protect the nesting females and the hatchlings. Due to TB having tourist and other development on it there is no easy way of controlling who visits and uses the beach. However, getting locals involved is another way to use the community as a good policing force to help conserve the beaches when patrols are not on the beach. With a group as small as SOS Tobago, they are unable to man the beaches at all time so local communities and tour guides play a vital role in helping protect the turtles and their nesting beaches and promoting further education about the species. In order to counteract the annual destruction of some beaches, hatcheries have been set up worldwide to improve the success rates of vulnerable nests, for example these projects have been set up in Costa Rica and Malaysia (Nordmoe et al, 2003). They aim to increase the hatching rate of its yearly nests, which would otherwise succumb to high tidal lines or rivers breaking through beaches.

Nesting females are now regularly tagged worldwide. SOS Tobago use flipper and electronic tags to identify their nesting populations. It is however hard to estimate the nesting adult mortality as they do not return every year. This needs to be studied in order to gauge the mortality rate in their nesting populations and compare to the success rate of nests hatching. Dutton et al (2001) did however point out that flipper tags for Leatherbacks in particular have been shown to be unreliable. This has then led to the general assumption that the survival rate of adult females is low due to the fact that tagged animals are rarely seen more than once. In 1989, in Costa Rica, many conservation projects were set up in order to protect their nesting numbers on Playa Grande, which by 1990 was sectioned in to the Las Baulas national park. The national park itself faces many problems concerning the conservation of their nesting turtle population. One major problem is that of overdevelopment due to increased tourism activities (Leatherback Trust, 2011). Constant pressure from beach side developers has highlighted the importance for further protection back from the high tide line. However, this protection does come at a hefty price as many developers want compensation (Restoring Our Watershed, 2009). 1.3 Aims and Hypothesis This study will be investigating whether more confirmed lays (CL’s) occurred on a developed beach (TB) or a secluded beach (BB). It will also discuss the main factors affecting the success rates of turtle nests and the possible problems depending on what beach is preferred 1.3.1 Null hypothesis (Nº) The null hypothesis (Nº) is that there will be no difference in number of confirmed lays on TB and BB in the nesting season of 2008. 1.3.2 Alternative hypothesis (N¹)

The alternative hypothesis (NÂš) is that there will be a significant difference in the number of CLâ&#x20AC;&#x2122;s between the beaches in the nesting season of 2008.

Chapter 2 2.0 Method 2.0.1 Location of study The location of the two beaches that were studied was on the Caribbean Island of Tobago. Tobago is located 11: 15’ 0 N, 60: 40’ 0 W. The two beaches are located on the southern part of the island, on the Caribbean shore. 2.0.2 Study sites 2.0.2.1 Turtle Beach (TB) Figure 2.0 is a satellite image of Turtle beach it is a mile long stretch of beach and has developments on it, so it is directly affected by human influence.

Figure 2.0: satellite image of Turtle Beach, Tobago. Source: © Google Imagery 2011

2.0.1.2 Back Bay, Mt Irvine (BB) Figure 2.1 is a satellite image of Back Bay, which is a secluded beach that has no development on it and is set back from the main road, where artificial street lighting is blocked by vegetation.

Figure 2.1: satellite image of Back Bay, Tobago. Source: © Google Imagery 2011

2.0.3 Data collection method The nesting season in Tobago is from Feb/Mar – Jun/Jul. All the CL data from the months of April – July in 2008 was highlighted to be analysed. To gather this information SOS Tobago had regular nightly patrols every day of the week, from beginning of April until July. Patrol shifts lasted from 20:00 till 04:00 on TB and BB. The patrols walked the beach very half an hour (30 mins) to check for turtle activity. When a turtle was approaching they would note down the time seen, beach it was seen on and the specific zone, species of turtle (in this case Leatherback), date and weather conditions. Only when the turtle was laying were they able to take accurate measurements of the turtle and acquire tagging information or apply tags. Once the turtle had finished laying it would be considered a confirmed lay (CL) and a GPS reading would be taken from directly over the nest. All the CL’s from the 2008 nesting season were highlighted and the information was processed. The key information that was needed was; whether it was a CL, and what beach - TB or BB.

Once all the data was collected at least one person was left with the turtle to make sure it returned to the water. This was a preventative measure to make sure the turtle did not go inland and also to protect it from poachers. This technique is also proving quite effective in Gabon where there was an issue with nesting females going inland (Deem et al, 2007) due to artificial lighting. During the season data sheets were collected and loaded up on to Excel. Each piece of information is noted down in individual cells in simple layout. For example the columns are set out as Date/Species of turtle/Location (i.e. what beach and what zone?)/Time in and out/Activity when first seen/Outcome (i.e. CL)/GPS reading. 2.0.4 Data analysis method The data was analysed to see whether there was any significant difference between the number of CL’s on TB and BB. The 2008 set of data had a sample size of 346 (n=346). This data was then used to see whether there was any significance between the two data samples on the developed and secluded beaches. Only CL’s were used as they were the most accurate account of successful nests on each beach. SPSS v. 18 was used to analyse the data. SPSS is a statistical package that can carry out specific tests on data samples and produce results that allow them to accept or reject their hypotheses. In this study the data needed to be tested to see whether there was any significance between the variables. The Shaprio – Wilk test was used in order to test for normality, this was used instead of the Kolmogorov – Smirnoff test as the sample size was < 50. To gain whether there is a significant difference between the two groups (TB and BB) an ANOVA (analysis of variance test) will be used. This will produce a p – value (<> 0.05) and a critical value of f including the degrees of freedom.

Chapter 3 3.0 Results 3.0.1 Differences in CL numbers Data from 2008 shows a general preference of chosen nesting beach for TB and BB. Shown simply in Table 1.0 and Table 2.0 there is an observed difference in CL’s over the 2008 nesting season for both beaches.

Table 3.0: shows the amount of CL’s 2008 nesting season on Turtle Beach. Source: SOS Tobago 2011

Nesting beach

No. of CL's

TB 2008

255

Table 3.1: shows the amount of CL’s 2008 nesting season on Back Bay. Source: SOS Tobago 2011

Nesting beach BB 2008

No. of CL's 34

3.0.2 Pattern of nesting for the 2008 nesting season It was clear to see which beach was the most popular for nesting sites. TB always had the more CL’s than the secluded beach, BB. Turtles that nest on TB are more likely to come into human contact, so with this in mind most would have thought it would have had less CL’s. Figure 3.0 shows the nesting pattern throughout the study period from April – July.

Number of confirmed lays (CL's)

Line graph showing the amount of confirmed lays on both beaches for the 2008 nesting season 150 100 Turtle beach '08 50

Back Bay '08

0 April

May

June

July

Figure 3.0: line graph representing the number of confirmed lays (CL) on both TB and BB for the 2008 nesting season. Source: SOS Tobago 2011

This line graph shows that as the nesting season goes on the number of CL’s increases on both beaches. While, there are more occurrences of CL’s on TB compared to BB, they both increase at the same time. The usual pattern is a general increase, more steeply on TB from April to June and then the numbers of CL’s begin to drop towards the end of the nesting season (generally after June). 3.0.3 Distributions across TB and BB Figure 3.1 indicates that the number of CL’s on BB range from (0 – 17), with a mean/average number of CL’s at 8.25 compared to TB that has an average of 63.75. TB has a larger range of CL’s in the same nesting season (7 – 119). This parallel boxplot gives a visual impression of how the medians of the distribution compare across both beaches (Samuels & Witmer, 2003). It clearly shows that TB (developed beach) had more confirmed lays across the nesting season than BB (secluded beach).

Figure 3.1: boxplot showing the mean, range, upper and lower quartiles of confirmed lays on both beaches. Source: SPSS v. 18 2011

The data for BB and TB were seen as normally distributed as illustrated in Figure 3.2 and Figure 3.3. The Shaprio – Wilk test gave a significance reading of 0.925 for BB (secluded beach) and a significance reading of 0.981 for TB (developed beach). Due to the sig values being >0.05 this test shows us that the data is normally distributed. This does not tell us whether we can reject or accept any of the hypotheses (H0 or H1). Figure 3.2 shows the normal distribution of CL’s on TB (Developed beach/ Beach =A). It shows that for the sample size on TB (n=4) had a mean (63.75± 46.385) of CL. The data is normally distributed as demonstrated by the “bell – shaped” curve.

Figure 3.2: a histogram showing frequency of confirmed lays on Beach A (TB). The normal distribution curve shows that data is normally distributed. Source: SPSS v. 18 2011

Figure 3.3 is a histogram showing the normal distribution of CL’s on BB (secluded beach/Beach = B). It shows for the sample size (n=4) had a mean (8.25±6.994) of CL’s. The distribution is normal as the data from this beach is represented by a “bell-shaped” curve. 24

Figure 3.3: a histogram showing frequency of confirmed lays on Beach B (BB). The normal distribution curve shows that data is normally distributed. Source: SPSS v. 18 2011

These normal levels of distribution are also represented by Q-Q plots produced by SPSS v.18. As shown here in Figure 3.4 and Figure 3.5.

Figure 3.4: a normal Q-Q plot of confirmed lays on Beach A = TB. Source: SPSS v.18

Figure 3.4 indicates that the observed points on TB generally follow the expected normal line. There is not too much deviation from the norm and the observed data points show a positive relationship.

Figure 3.5: a normal Q-Q plot of confirmed lays on Beach B = BB. Source: SPSS v.18

Figure 3.5 illustrates that the distribution of CL’s on BB generally follows the expected norm, shows little deviation from the normal distribution line and shows a positive relationship. 3.0.4 Significance between the two beaches The ANOVA test gave a p – value of (p= 0.056) as shown in APPENDIX I. The F value was F₁,₇=5.599, p≤0.05. The F ratio is 5.599 with (1,7) degrees of freedom means this result is more or less significant at the level of probability (p≤0.05). Figure 3.6 shows the difference in number of CL’s in 2008 on TB and BB. It clearly shows that the developed beach is the most preferred beach for nesting on. This bar chart does not indicate why TB has more CL’s. It does, however, give an accurate reading of the number of recorded CL’s on both beaches.

Number of confirmed lays (CL's)

Number of confirmed lays (CL's) on both TB and BB for the 2008 nesting season 300 255 250 200 TB 2008

150

BB 2008

100 34

50 0

Figure 3.6: a bar chart illustrating the amount of confirmed lays (CL’s) on both beaches (TB and BB) for the 2008 nesting season. Source: SOS Tobago 2011

This bar chart again shows the distinct difference in nests confirmed on both the secluded beach (BB) and developed beach (TB). Figure 3.7 shows the mean number of CL’s per beach. TB had (63.75 ± 23.19) and BB had (8.25 ± 3.49). The error bars on this bar chart indicate the standard error for each mean amount of CL’s on each beach, indicating how far the population mean could differ from the sample mean.

Bar chart showing mean number of CL's on both beaches and the stand error for each Mean number of CL's

100 80 60

TB BB

40 20 0

Figure 3.7: mean number of CL’s per beach and their individual standard errors. Source: Microsoft Excel 2011.

Chapter 4 4.0 Discussion 4.0.1 Analysis of findings and results The alternative hypothesis (H1) was that there would be a significant difference between numbers of CL’s on the two beaches. The data was analysed by SPSS v. 18 and the specific tests used came to the conclusion that p – value = 0.056, which is close enough to the significant value of (0.05) and F – value = 5.599 which allowed us to accept the alternative hypothesis and that the developed beach was the most preferred nesting site. The Shaprio - Wilk test showed that the data was normally distributed (0.925, BB and 0.981, TB). This then told us that in order to find the difference between two sets of data that were normally distributed, an ANOVA test could show if there was any significant difference. The p- value was calculated at (p=0.056) so this result was pretty much significant due to the p – value being so close to (≤0.05). The critical f ratio value given (5.599) indicated by the ANOVA test showed that we can accept the alternative hypothesis (H1) with 95% chance of probability and the probability of the null hypothesis being true is very unlikely. This was due to the critical value (f=5.599) being the same as the critical f value shown at the (0.05) p-value level in the table for critical values for ANOVA testing at (1,7) degrees of freedom, which was (f=5.599). So we can assume that there is a significant difference between the numbers of CL’s on the two beaches. This approach could be used to test whether other developed beaches are preferred around the world for nesting activity. Further studies could then be undertaken to determine why this might be the case. One explanation could be that artificial lighting could be guiding the nesting females in to nest. If this is right, more conservation strategies might be necessary to

make sure that development on or near nesting beaches does not have a negative effect on the adult emergence success and on successful hatches. Table 3.0 and Table 3.1 shows that the nesting population nests more on the developed beach than the secluded beach. Figure 1.1 (SOS Tobago, 2011) supports the belief that Leatherback nesting populations are either increasing or remaining stable, as suggested by Dutton et al (2005). They believe that this increasing or otherwise stabilising population is linked to the effectiveness of long-term nest protection. It is groups like SOS Tobago that help protect these nesting populations and the figures show that protecting nesting beaches is a key conservation strategy. 4.0.2 Limitations to study There are several limitations to this study. Due to SOS Tobago being quite a small conservation group, it makes it very difficult to patrol every beach all the time, so not all the turtle activity from the 2008 nesting season may have been recorded. It relies heavily on volunteers to form their patrol parties and so data collection efficiency changes depending on who is patrolling. By relying heavily on volunteers it means that in some years there may be more patrollers than in others. So the data across a number of years might be of some variation in quality. Leatherbacks usually return to the same geographical area when they come to nest, but they do not generally nest on the same beach where they were born, unlike Green and Hawksbill turtles. SOS Tobago only patrols three beaches (Turtle Beach, Back Bay Mt. Irvine and Grafton Beach). Leatherbacks nest on many other suitable beaches across the island. So in order to get a proper representation of the nesting population on Tobago every beach would have to be patrolled. This would enable all beaches affected by development and those that are secluded to be properly analysed to see whether the results for TB and BB are representative of the islandâ&#x20AC;&#x2122;s nesting population as a whole. 29

The two beaches themselves are located on the same coastline and are not that far from each other. The main difference between the two is size: TB is a mile long stretch while BB is smaller. So the two study sites are not the same size, which means there is more chance for more nests to occur on the larger beach. However, like many conservation groups around the world, funding is a major issue. This restricts them from advancing their conservation techniques. According to SOS Tobago (2011) they rely on charitable donations from tourists and other supporters of their organisation. Due to their not having a reliable constant flow of funding it means that their activities and conservation programmes are somewhat restricted. At the busiest parts of the nesting season some information may not get recorded due to lack of patrollers or even adverse weather. The results do not represent the whole nesting population or every nest. Some nests may have been missed during the studied period (April-July, 2008). There is a chance that there could have been an error in the sample sizes (n). A turtle may have been missed and a nest unaccounted for, so the sample size (n) may not be the total number of CL’s for the season. It is also just a proportion of the nesting season, which is supposedly at its height between April – July. However many nests may be present before or even after this time. The results do not account for a nesting season where there may be a flurry of early or late nests. The data cannot, however, show whether development has a negative impact on the nests on TB. Development means increased human activity, which in turn increases the risks of turtle disturbance and nest mortality. All the data shows is that a developed beach, with artificial lighting, has statistically more CL’s than a secluded beach, without artificial lighting. The results do not account for the number of successful nests, so the hatching success of each year is unknown. Even though the data proves that the secluded beach has fewer CL’s for each

nesting season studied, it may have had a higher hatching success rate compared to the developed beach. The study explained in Chapters 2 and 3 would need to be undertaken over a longer period of time in order to give a clearer indication as to whether adverse impacts on nesting patterns were emerging due to tourism and other human interactions. Long standing studies are, however, quite costly and there would need to be sufficient tools and competent patrollers to record every CL for a certain number of years in order to investigate the relationship between a developed beach and high numbers of CL’s even further. Resolving the light issue on TB is a big problem. A good point is made by Witherington & Martin (2000) “One person’s environmental threat may be another person’s safety and security”. On Tobago some sort of an agreement needs to be reached in order to ensure the protection of turtles and their nesting beaches and the safety of people’s property and in some cases their livelihood, in TB’s case relating to lighting at the fisheries and at Plymouth to protect fishing equipment and boats. Measures to ensure lighting restrictions are abided by will need regular inspections and time for property/development owners to change their “problem” lights. This would be beneficial but at the same time quite time consuming and costly. 4.0.3 Recommendations for future research and conservation Bell et al (2006) believed that problems that developments may be causing for the incidence and success rate of nesting is worth investigating. By further studying the hatching success on both the developed and secluded beaches, SOS Tobago could put in to practice conservation measures that would ensure a greater hatching rate, to combat the increased risk of human traffic on developed beaches especially reducing the chances of nests being successful. Development also means a higher potential of increased lighting and this means an increased potential relationship between development and disorientation of hatchlings. It would be easy 31

to say that females would be disturbed more easily on developed beaches due to the high risk of artificial lighting and human traffic, and so conclude that there would be a noticeable decline in adult emergence (Miller, 1999). However, in the Grand Cayman Islands, Bell et al (2006) found that there was no relationship between development density and adult emergence success on all of the beaches. In Tobago it is hard to see whether the developments affect adult emergence as the developments have been there for so long. SOS Tobago can introduce measures to ensure the developments do not affect adult emergence by making sure less lighting spills on to the beach, and that â&#x20AC;&#x153;less invasiveâ&#x20AC;? (yellow light) lighting is used, as in Florida (Witherington & Martin, 2000). Worldwide the most readily accepted measure for light control is to manage it rather than prohibit it. Along with studying the hatching success rates of the developed and secluded beaches, SOS Tobago could benefit from studying the relationship between development/artificial lighting and disorientation of successful nests, and investigating how many nests are affected by development and its artificial lighting. Moving the nests to hatcheries lowers the risk of development and lighting having a negative effect on hatchlings. If SOS Tobago were to introduce a hatcheries programme they could improve the success rate of the vulnerable nests, those at risk from high human traffic activity, rivers, drains and the high tide line. By introducing this technique they would able to closely monitor and regulate the nests to give them more chance of hatching. It has been shown in other conservation projects that hatcheries do increase the hatching success of nests. If SOS Tobago were to secure a constant source of funding a hatcheries programme would be an ideal next step to ensure those vulnerable nests have a higher chance of being successful. This could then hopefully increase the hatching success rate to around 57% as found by Furler, 2005.

To really understand the Leatherbacksâ&#x20AC;&#x2122; life at sea, more research is needed into their migratory routes and the location of their popular feeding grounds in the oceans. Technology such as satellite tagging has already been proven to give key information about their specific routes. This could in time help biologists understand why and where the high adult mortality rates are occurring out to sea. The technology now used in tracking turtles worldwide allows scientists to see where these tags are going and whether they have been removed from the water. Hays et al (2003) calculated a high level of adult mortality whilst satellite tracking certain individuals over the world. It has, however, been identified that some tagging equipment can be more harmful than informative. Flipper tags have been known to get them caught up in fishing gear or litter debris and in doing so raising the levels of adult mortality (Nichols & Seminoff, 1998; Suggett & Houghton, 1998).

Chapter 5 5.0 Conclusion 5.0.1 Summary and evaluation The ANOVA test allowed us to accept the alternative hypothesis (H1) that the developed beach has more CL’s than the secluded beach showing a significant difference in CL’s recorded, represented by the f and p values (F₁,₇=5.599, p≤0.05). There were by far more CL’s recorded on the developed beach than the secluded beach. This shows that most nesting females are not put off from nesting on the developed beach. This is beneficial from a tourism point of view as TB is easily accessible compared to BB. However, this could be costly to the turtle population if measures to restrict human-induced mortality are not put in place. As tourism grows on Tobago more research needs to go in to how beach side development may be having an effect on their Leatherback nesting populations. As Maison et al (2000) pointed out, as coastal developments increase there needs to be a constant monitoring of the Leatherback nesting numbers to make sure there are no negative side effects. By gaining more information on the effects developments and other human activities have on the nesting populations on Tobago it would help inform hotels and the government about future action plans and conservation management to ensure safe protection of this ancient majestic species. Fencing or moving nests to hatcheries on more suitable parts of the beach would be a way of eradicating the loss of nests through human traffic. However, it would make the nests easier targets for poachers and would have to be guarded on a regular basis. Hatcheries need a great deal of biological and ecological data support in order to be successful. Trying to involve local communities in more educational and conservation programmes may help change people’s views on conserving the Leatherback numbers. 34

Itâ&#x20AC;&#x2122;s hard to tell whether development on TB had an overall effect on total adult emergence on Tobago for the 2008 nesting season. This would need to be studied further and more extensively. It did not seem to bother nesting females as there were significantly more CLâ&#x20AC;&#x2122;s on TB compared to the secluded beach BB, although there may be other reasons for the preference, such as beach topography and differences in bays and approaches to the beach. In some parts of the world, as previously discussed, lighting has a major affect on adult and hatchling turtles; however there are measures to combat these issues. On Tobago the results show that the amount of CLâ&#x20AC;&#x2122;s is not really affected by the presence of development and artificial lighting. However, the potential risk of hatchling disorientation and mortality is high. Further studies may find that the nesting population on Tobago may not be put off and disturbed by developed beaches but these beaches will more than likely have a higher hatchling mortality rate than secluded beaches. Lighting regulations have proven to be effective and could be a good compromise for the government in Tobago to put in place. It is clear to see that Leatherback populations all over the world face many problems. It is difficult to pin point specific problems for specific populations in some areas. But progress is being made in the way of increased nesting beach protection, old laws being revised and new laws being introduced. It is conservation groups, like SOS Tobago, that help spread the message of conservation through education and local activities. SOS is one of many groups at the forefront of this massive task, trying to save this majestic creature from becoming extinct - the Giant Leatherback Turtle.

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surveying of the worldâ&#x20AC;&#x2122;s largest leatherback turtle rookery: a more effective methodology for large â&#x20AC;&#x201C; scale monitoring, 142(8), 1719-1727.

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Appendix I Descriptives Beach Confirmed Lays

Statistic Mean

63.7500

95% Confidence Interval

Lower Bound

-10.0591

for Mean

Upper Bound

137.5591

5% Trimmed Mean

63.8333

Median

64.5000

Variance

2151.583

Std. Deviation

46.38516

Minimum

7.00

Maximum

119.00

Range

112.00

23.19258

Interquartile Range

88.75

Skewness

-.092

1.014

.690

2.619

8.2500

3.49702

Kurtosis B

Std. Error

Mean 95% Confidence Interval

Lower Bound

-2.8791

for Mean

Upper Bound

19.3791

5% Trimmed Mean

8.2222

Median

8.0000

Variance

48.917

Std. Deviation

6.99405

Minimum

.00

Maximum

17.00

Range

17.00

Interquartile Range

13.25

Skewness Kurtosis

.208

1.014

1.123

2.619

Descriptive stats of 2008 data. Beach A = TB (Developed beach) and Beach B = BB (secluded beach)

ANOVA Confirmedlays Sum of Squares

Mean Square

Between Groups

6160.500

Within Groups

6601.500

1100.250

12762.000

Total

F 5.599

Sig. .056

The ANOVA table that was created by SPSS v. 18 showing the p and f – values for the data. (p=0.056 and f – value=5.599).

Appendix II SOS NESTING EVENT DATA 2008 OUTCO MES BODY PIT ONLY - UNKNOWN OUTCOME: BP CONFIRMED LAY: CL ESTIMATED LAY: EL

FALSE CRAWL WITHOUT BODY PIT: FC CONFIRMED FALSE CRAWL WITH BODY BODY PIT: FCB UNKNOWN OUTCOME: UNK

DATE

SPE CIES

LOCA TION

ZO NE

TIME SEEN

01/04/2 008 06/04/2 008 06/04/2 008 12/04/2 008 17/04/2 008 20/04/2 008 20/04/2 008 21/04/2 008 21/04/2 008 21/04/2 008 21/04/2 008 22/04/2 008 22/04/2 008 23/04/2 008 23/04/2 008 23/04/2 008 29/04/2 008 29/04/2 008 06/05/2 008

23:00: 00 21:11: 00 21:30: 00 22:15: 00 23:58: 00 23:15: 00 21:47: 00 03:09: 00 00:05: 00 02:15: 00

02:15: 00 01:45: 00 21:42: 00 23:05: 00 22:59: 00 22:15: 00 20:55: 00 02:49: 00

TIME OUT

21:45 :00 00:36 :00

01:00 :00

03:45 :00

03:05 :00 02:30 :00 23:35 :00 01:05 :00 01:15 :00 23:45 :00

ACTIVITY

EVENT OUTCOM E

DIGGING

LAYING

DIGGING

APPROAC HING APPROAC HING APPROAC HING LAYING

UNK

APPROAC HING COVERIN G GONE

LAYING

COVERIN G LAYING

COVERIN G APPROAC HING COVERIN G

BODY PITTING

EL UNK

UNK EL

LONGI TUDE (NORT H)

LATIT UDE (WES T)

07/05/2 008 07/05/2 008 07/05/2 008 07/05/2 008 07/05/2 008 07/05/2 008 08/05/2 008 08/05/2 008 08/05/2 008 08/05/2 008 08/05/2 008 08/05/2 008 08/05/2 008 09/05/2 008 09/05/2 008 09/05/2 008 09/05/2 008 09/05/2 008 10/05/2 008 10/05/2 008 10/05/2 008 11/05/2 008 12/05/2 008 12/05/2 008 13/05/2 008 13/05/2 008 14/05/2 008 15/05/2 008 16/05/2

01:45: 00 23:45: 00 23:30: 00 03:15: 00 22:30: 00

LAYING

APPROAC HING LAYING

CL CL FC

02:15: 00 21:46: 00 03:14: 00 04:20: 00

DIGGING

LAYING

BODY PITTING BODY PITTING

UNK FC FCB

APPROAC HING APPROAC HING DIGGING

LAYING

APPROAC HING DIGGING

DIGGING

LAYING

DIGGING

BODY PITTING APPROAC HING APPROAC HING DIGGING

APPROAC HING LAYING

20:45: 00 22:45: 00 02:30: 00

22:15: 00 21:15: 00 00:39: 00 00:04: 00 22:39: 00

00:44: 00 01:58:

FC CL

FCB

UNK

CL CL CL

008 16/05/2 008 16/05/2 008 17/05/2 008 17/05/2 008 17/05/2 008 18/05/2 008 19/05/2 008 19/05/2 008 19/05/2 008 20/05/2 008 20/05/2 008 20/05/2 008 20/05/2 008 20/05/2 008 21/05/2 008 21/05/2 008 22/05/2 008 22/05/2 008 23/05/2 008 25/05/2 008 25/05/2 008 26/05/2 008 26/05/2 008 26/05/2 008 26/05/2 008 26/05/2 008 27/05/2 008 27/05/2 008

00 23:20: 00 02:50: 00 22:45: 00 00:21: 00 00:01: 00 00:50: 00 21:00: 00

22:52: 00 22:30: 00

00:10: 00 20:40: 00 21:15: 00 02:00: 00

04:58: 00 01:48: 00 21:52: 00 19:50: 00 DNS

21:16 :00

20:40: 00 00:40: 00 20:58: 00 22:02: 00 20:10: 00 05:20: 00 23:22: 00

LAYING

DIGGING

UNK

COVERIN G LAYING

DIGGING

LAYING

DIGGING

LAYING

DIGGING

UNK

LAYING

BODY PITTING DIGGING

DIGGING

UNK

LAYING

DIGGING

UNKNOW N LAYING

UNK

APPROAC HING DIGGING

LAYING

DIGGING

BODY PITTING APPROAC HING

UNK

27/05/2 008 28/05/2 008 28/05/2 008 28/05/2 008 28/05/2 008 28/05/2 008 28/05/2 008 28/05/2 008 28/05/2 008 29/05/2 008 29/05/2 008 29/05/2 008 29/05/2 008 29/05/2 008 29/05/2 008 29/05/2 008 29/05/2 008 29/05/2 008 29/05/2 008 29/05/2 008 29/05/2 008 29/05/2 008 29/05/2 008 30/05/2 008 30/05/2 008 01/06/2 008 01/06/2 008 01/06/2 008 03/06/2

19:45: 00 22:18: 00 20:45: 00 21:14: 00 23:50: 00 DNS

DNS

01:24: 00 01:30: 00 02:50: 00 18:45: 00 21:26: 00 20:50: 00 21:30: 00 22:00: 00 22:54: 00 22:29: 00 20:00: 00 20:00: 00

20:50: 00 00:40: 00 00:45: 00 23:00: 00 21:40: 00 23:30: 00 02:30:

00:06 :00

00:00 :00

22:44 :00 22:25 :00

23:30 :00

21:00 :00 21:30 :00

20:55 :00

GONE

UNK

LAYING

APPROAC HING LAYING

LAYING

APPROAC HING UNKNOW N UNKNOW N UNKNOW N APPROAC HING LAYING

LAYING

DIGGING

BODY PITTING LAYING

APPROAC HING LAYING

LAYING

DIGGING

LAYING

LEAVING

UNK

LAYING

UNK UNK UNK CL CL

11.11.9 19 11.11.9 36

60.47. 712 60.47. 644

11.11.9 48

60.47. 612

008 03/06/2 008 03/06/2 008 04/06/2 008 04/06/2 008 05/06/2 008 05/06/2 008 06/06/2 008 06/06/2 008 06/06/2 008 06/06/2 008 06/06/2 008 06/06/2 008 06/06/2 008 06/06/2 008 07/06/2 008 07/06/2 008 07/06/2 008 07/06/2 008 07/06/2 008 07/06/2 008 07/06/2 008 07/06/2 008 08/06/2 008 08/06/2 008 09/06/2 008 09/06/2 008 09/06/2 008 09/06/2 008

00 LB

GONE

UNK

GONE

UNK

LAYING

GONE

UNK

LAYING

DIGGING

LAYING

DIGGING

FCB

LAYING

DIGGING

LAYING

APPROAC HING DIGGING

LAYING

DIGGING

LAYING

04:09: 00 02:45: 00 23:15: 00

00:02: 00 00:35: 00 01:30: 00 02:45: 00 23:50: 00 00:45: 00 00:05: 00 02:15: 00 03:15: 00 04:21: 00 21:40: 00 03:45: 00 21:45: 00 03:00: 00 00:30: 00 20:58: 00 22:20: 00 00:55: 00 00:15: 00 04:00: 00 23:50: 00 03:45: 00

01:20 :00

02:37 :00

01:00 :00

11.11.9 12

60.47. 760

09/06/2 008 09/06/2 008 09/06/2 008 10/06/2 008 10/06/2 008 10/06/2 008 10/06/2 008 11/06/2 008 11/06/2 008 11/06/2 008 11/06/2 008 11/06/2 008 11/06/2 008 12/06/2 008 12/06/2 008 12/06/2 008 13/06/2 008 14/06/2 008 14/06/2 008 14/06/2 008 14/06/2 008 14/06/2 008 14/06/2 008 14/06/2 008 15/06/2 008 15/06/2 008 15/06/2 008 15/06/2 008 15/06/2

00:57: 00 23:10: 00 03:30: 00 03:50: 00 02:30: 00 23:15: 00 21:42: 00 00:00: 00 05:54: 00 00:30: 00 20:30: 00 22:32: 00 23:10: 00 21:12: 00 20:00: 00 23:45: 00 23:45: 00 01:30: 00 00:50: 00 02:30: 00 03:30: 00 03:40: 00

00:30 :00

02:43: 00 02:25: 00 02:15: 00 23:00: 00 23:30: 00 06:01:

LAYING

DIGGING

COVERIN G LAYING

BODY PITTING LAYING

LAYING

DIGGING

LAYING

APPROAC HING LAYING

LAYING

BODY PITTING DIGGING

LAYING

DIGGING

LAYING

008 15/06/2 008 16/06/2 008 16/06/2 008 16/06/2 008 16/06/2 008 16/06/2 008 16/06/2 008 16/06/2 008 16/06/2 008 16/06/2 008 16/06/2 008 16/06/2 008 16/06/2 008 16/06/2 008 16/06/2 008 17/06/2 008 17/06/2 008 17/06/2 008 18/06/2 008 18/06/2 008 18/06/2 008 18/06/2 008 18/06/2 008 19/06/2 008 19/06/2 008 19/06/2 008 19/06/2 008 19/06/2 008

00 23:13: 00 22:07: 00 00:45: 00 00:58: 00 01:30: 00 01:30: 00 01:45: 00 23:38: 00 02:30: 00 02:30: 00 21:50: 00 20:43: 00 01:45: 00 02:30: 00 02:45: 00 05:01: 00 04:30: 00 02:41: 00 01:13: 00 04:45: 00 20:05: 00 07:21: 00 00:54: 00 00:14: 00 03:11: 00 03:45: 00 02:51: 00 02:21: 00

22:40 :00 22:21 :00

DIGGING

APPROAC HING LAYING

DIGGING

LAYING

BODY PITTING DIGGING

LAYING

APPROAC HING BODY PITTING LAYING

LAYING

BODY PITTING BODY PITTING DIGGING

LAYING

DIGGING

LAYING

11.11.9 25

60.47. 666

11.11.9 30 11.11.9 03

60.47. 636 60.47. 750

CL CL

19/06/2 008 19/06/2 008 19/06/2 008 19/06/2 008 19/06/2 008 20/06/2 008 20/06/2 008 20/06/2 008 20/06/2 008 21/06/2 008 21/06/2 008 21/06/2 008 22/06/2 008 23/06/2 008 23/06/2 008 23/06/2 008 23/06/2 008 24/06/2 008 24/06/2 008 24/06/2 008 24/06/2 008 24/06/2 008 24/06/2 008 25/06/2 008 25/06/2 008 25/06/2 008 25/06/2 008 26/06/2 008 26/06/2

22:34: 00 22:39: 00 01:50: 00 04:12: 00 00:45: 00 02:30: 00 03:25: 00 20:35: 00

22:21: 00 21:30: 00 13:05: 00 23:12: 00 21:40: 00 22:32: 00 22:39: 00 23:57: 00 20:45: 00 23:45: 00 22:39: 00 22:45: 00 22:15: 00 23:30: 00 04:35: 00 03:00: 00 02:49: 00 01:05: 00 00:00: 00 01:39:

23:55 :00

23:41 :00

LAYING

DIGGING

BODY PITTING LAYING

UNK

BODY PITTING APPROAC HING GONE

DIGGING

LAYING

BODY PITTING LAYING

BODY PITTING DIGGING

COVERIN G LAYING

LAYING

DIGGING

LAYING

CL UNK

11.12.7 67

60.46. 734

008 26/06/2 008 26/06/2 008 26/06/2 008 26/06/2 008 26/06/2 008 26/06/2 008 26/06/2 008 26/06/2 008 26/06/2 008 26/06/2 008 26/06/2 008 26/06/2 008 26/06/2 008 26/06/2 008 26/06/2 008 27/06/2 008 27/06/2 008 27/06/2 008 27/06/2 008 27/06/2 008 28/06/2 008 28/06/2 008 28/06/2 008 28/06/2 008 29/06/2 008 29/06/2 008 29/06/2 008 30/06/2 008

00 01:52: 00 02:55: 00 21:46: 00 23:30: 00 22:05: 00 05:10: 00 21:59: 00 22:00: 00 01:35: 00 02:20: 00 02:30: 00

04:59 :00

23:45 :00

04:04 :00 03:04 :00

05:45 :00 02:49: 00 20:14: 00 21:49: 00 22:30: 00 00:45: 00 00:12: 00 01:40: 00

21:59: 00 22:40: 00 23:05: 00 23:11: 00 02:45: 00 04:45: 00 21:57: 00 00:41: 00

22:40 :00

23:20 :00

22:19 :00 01:56 :00

LAYING

APPROAC HING COVERIN G LAYING

DIGGING

LAYING

APPROAC HING LAYING

LAYING

CAMOUFL AGING LAYING

LAYING

GONE

UNK

LAYING

APPROAC HING LAYING

LAYING

CAMOUFL AGING DIGGING

CL CL 11.11.9 24

60.47. 654

11.11.9 47

60.47. 614

11.11.9 37 11.11.9 31

60.47. 635 60.47. 641

30/06/2 008 30/06/2 008 30/06/2 008 30/06/2 008 01/07/2 008 01/07/2 008 02/07/2 008 02/07/2 008 02/07/2 008 02/07/2 008 02/07/2 008 02/07/2 008 02/07/2 008 02/07/2 008 03/07/2 008 04/07/2 008 04/07/2 008 04/07/2 008 04/07/2 008 04/07/2 008 04/07/2 008 04/07/2 008 04/07/2 008 04/07/2 008 05/07/2 008 05/07/2 008 06/07/2 008 06/07/2 008 06/07/2

00:45: 00 22:30: 00 22:59: 00 22:54: 00 23:49: 00 21:59: 00 04:40: 00 02:40: 00 21:40: 00 01:45: 00 02:30: 00 00:00: 00 23:45: 00

01:45 :00 23:31 :00

00:05 :00

01:32: 00

LAYING

DIGGING

UNK

LAYING

APPROAC HING BODY PITTING GONE

LAYING

UNK EL

CL 02:05: 00 01:30: 00 01:06: 00 23:07: 00 03:01: 00 23:55: 00 03:55: 00 20:30: 00 00:21: 00 01:45: 00 23:45: 00 01:30: 00 01:50:

02:42 :00

05:10 :00

00:31 :00

LAYING

APPROAC HING DIGGING

APPROAC HING LAYING

LAYING

APPROAC HING DIGGING

FCB

DIGGING

11.11.9 46

60.47. 610

008 06/07/2 008 06/07/2 008 07/07/2 008 07/07/2 008 07/07/2 008 07/07/2 008 07/07/2 008 07/07/2 008 07/07/2 008 07/07/2 008 07/07/2 008 07/07/2 008 07/07/2 008 07/07/2 008 07/07/2 008 08/07/2 008 08/07/2 008 08/07/2 008 08/07/2 008 09/07/2 008 09/07/2 008 09/07/2 008 09/07/2 008 09/07/2 008 09/07/2 008 09/07/2 008 10/07/2 008 10/07/2 008

00 LB

01:30: 00 23:04: 00 01:30: 00 02:00: 00 00:20: 00 01:26: 00 02:56: 00 22:45: 00 00:00: 00 21:45: 00 01:10: 00 00:00: 00 23:22: 00 01:00: 00 23:25: 00

00:00 :00 03:00 :00 03:30 :00

04:40 :00 00:50 :00 22:30 :00 22:55 :00 03:13 :00

23:25 :00 02:05 :00 00:55 :00

21:15: 00 01:10: 00 02:56: 00 05:00: 00 23:13: 00

23:29: 00 01:30: 00 02:20: 00 03:40: 00 00:48: 00

LAYING

DIGGING

APPROAC HING APPROAC HING APPROAC HING BODY PITTING DIGGING

APPROAC HING APPROAC HING CAMOUFL AGING DIGGING

APPROAC HING DIGGING

APPROAC HING APPROAC HING APPROAC HING BODY PITTING LAYING

60.47. 667

11.11.9 37 11.11.9 34 11.11.9 41

60.47. 640 60.47. 638 60.47. 614

11.11.9 36

60.47. 640

CL CL CL FCB

CL EL CL

FCB CL CL CL CL

02:09 :00

11.11.9 27

APPROAC HING DIGGING

LAYING

BODY PITTING APPROAC HING LAYING

DIGGING

UNK CL

10/07/2 008 10/07/2 008 10/07/2 008 10/07/2 008 10/07/2 008 10/07/2 008 10/07/2 008 12/07/2 008 12/07/2 008 12/07/2 008 13/07/2 008 13/07/2 008 14/07/2 008 14/07/2 008 15/07/2 008 15/07/2 008 16/07/2 008 16/07/2 008 16/07/2 008 16/07/2 008 16/07/2 008 16/07/2 008 17/07/2 008 18/07/2 008 20/07/2 008 20/07/2 008 20/07/2 008 20/07/2 008 21/07/2

01:02: 00 01:45: 00 03:00: 00 04:20: 00 02:00: 00 03:15: 00 11:25: 00 02:00: 00 00:51: 00 01:35: 00 22:23: 00 21:29: 00 22:30: 00 00:57: 00 23:00: 00 00:15: 00 01:54: 00 02:45: 00 00:30: 00 03:26: 00 11:40: 00

02:10: 00 13:00: 00 22:50: 00 03:08: 00 23:33: 00 03:05:

03:00 :00 23:33 :00

23:28 :00

00:21 :00 04:15 :00 15:20 :00

04:04

APPROAC HING LAYING

DIGGING

LAYING

DIGGING

APPROAC HING DIGGING

FCB

DIGGING

COVERIN G DIGGING

DIGGING

APPROAC HING DIGGING

LAYING

DIGGING

UNK

DIGGING

APPROAC HING DIGGING

BODY PITTING DIGGING

APPROAC HING DIGGING

11.11.1 30

60.47. 663

11.11.9 45 11.12.3 95

60.47. 610 60.46. 504

11.12.4 21

60.46. 474

008 21/07/2 008 21/07/2 008 21/07/2 008 22/07/2 008 22/07/2 008 23/07/2 008 24/07/2 008 24/07/2 008 25/07/2 008 25/07/2 008 26/07/2 008 27/07/2 008 27/07/2 008 27/07/2 008

00 23:26: 00 02:45: 00 01:09: 00 22:40: 00

21:34: 00 03:35: 00 00:50: 00 02:29: 00 23:16: 00 22:15: 00 20:45: 00 10:28: 00 21:30: 00

:00 01:57 :00

00:03 :00

23:24 :00

APPROAC HING APPROAC HING APPROAC HING DIGGING

GONE

APPROAC HING APPROAC HING

11.11.5 69

60.47. 367

11.12.2 52

60.47. 032

CL CL

APPROAC HING LAYING

LAYING

COVERIN G APPROAC HING DIGGING

CL CL

Raw data for 2008 nesting season supplied by SOS Tobago. Source: Excel (2011)

60.47. 395

21:20 :00 00:11 :00 22:42 :00

11.11.5 57