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Operation Wallacea students participate in sea turtle research

Green sea turtles (Chelonia mydas) are one of only seven remaining sea turtle species. These reptiles were classified as an endangered species on the IUCN Red list, following the abrupt decline of populations due to overexploitation and habitat loss. Although the green sea turtle  is protected in Bahamian waters, it is still of great importance to investigate the factors that influence where juveniles choose to forage, as this life cycle stage is crucial to the species’ ability to grow and thrive. Seagrass beds play a critical role within this life cycle stage acting as a key food source for the green sea turtle, and therefore vital for development. This summer, at the Cape Eleuthera Institute, Trinity College Dublin student Anna Whitaker, Oxford University student Alison Maughan and Royal Holloway University of London student Kate Rowley, aim to carry out research which could contribute to the improvement of future conservation efforts of the green sea turtle. A total number of 9 mangrove creeks were studied in this experiment. At each creek they visited, quadrats were placed and used for the investigation of seagrass structure, where percentage cover, species richness, and leaf canopy height data were collected. As well as this, environmental factors of the area, such as water depth, were studied. Samples of seagrass were also taken using a core.

Two CEI interns catching turtles with a seine net (turtle seining)

Laboratory analysis of the seagrass samples was used to identify the determinants of sea grass density. This analysis included calculating the number of leaves and shoots in each core taken. After which, the biomass of the samples were calculated by dividing out the core samples into above and below-ground matter. These seagrass samples were heated, and therefore dry weights of above and below ground seagrass matter could be taken.

In order to collect data regarding the abundance of turtles, methods including turtle seining, chasing and abundance surveys were carried out within the creeks where seagrass data had previously been collected. These methods sought to demonstrate correlations between characteristics of the seagrass and the abundance of turtles.

Measuring a captured juvenile green sea turtle (Chelonia mydas) at Half Sound, Eleuthera

Within each creek, a number of different habitat types were studied, including the mouth, silty mangroves, warm shallow waters, and seagrass meadows.

In addition, this project has collaborated with numerous programs, such as Earthwatch, allowing this research to connect with educational outreach and inspire young marine biology enthusiasts.

Sea Turtle Research Interns (front row) and Earthwatch students (back row)

The data collected will identify the fine-scale patterns of site selection and resource use of foraging grounds. This will contribute to a better and more in depth understanding of green sea turtle habitat usage. The research objectives of this study will form the basis for Alison, Kate and Anna’s undergraduate dissertation projects. We thank them for their help and wish them all the best with their studies!

 

The Bahamas National Trust Co-hosts Caribbean Shark Conservation Symposium

The Bahamas National Trust (BNT) joined the Government of St. Maarten, St. Maarten Nature Foundation, and The Pew Charitable Trusts as hosts of the Caribbean Shark Conservation Symposium, which took place from Tuesday, June 13 through Thursday, June 16.  The gathering of Caribbean island government officials, environmental NGOs, and global shark conservation experts was coordinated to discuss the future of shark conservation in the region. As the first Caribbean country to establish a shark sanctuary and a leader in the region, the voice of the The Bahamas was represented at the meeting by Eric Carey, Executive Director of BMT.

Caribbean Reef Sharks - photo by Jim Abernethy

Carey said: “The Bahamas National Trust has been promoting shark conservation for many years. Our efforts to secure the longline ban nearly 30 years ago, presented an incredible opportunity to protect intact shark populations. Our being asked to cohost this meeting is a clear indication that the actions taken by The Bahamas to protect our sharks, has distinguished us as a leader in ocean conservation in the Caribbean. BNT is proud to have played a part in this.”

Also in attendance was Virgin Group Founder Sir Richard Branson, who has been supportive of establishing regional shark protections throughout the Caribbean, and cohosted a similar meeting in Bimini, The Bahamas in 2015.

During the meeting, four Caribbean governments committed to help reverse this trend by fully protecting sharks in their waters. St. Maarten and the Cayman Islands announced that their economic zones (EEZs) are completely closed to commercial shark fishing.   Additionally, Curacao announced that they will establish legislation this year that will protect sharks in their waters, and Grenada is considering measures that would safeguard sharks within the country’s EEZ. Together, the two new sanctuaries cover a total of 119,631 square kilometers and raise the total number of Caribbean sanctuaries to seven.

The findings of a study of the economic impact of sharks on The Bahamas’ tourism industry were also released at the meeting. Lead investigator, Dr. Edward Brooks from the Cape Eleuthera Institute, was in attendance to discuss the study, which found that sharks generate US$113 million annually in direct expenditure and value added through tourism to the Bahamian economy.

Lemon Shark - photo by Jim Abernethy

Brooks said: “The results of our study illustrate the importance of the ongoing stewardship of sharks and rays demonstrated by The Bahamian Government over the last 25 years, for which they are now reaping the economic rewards.  However, despite the actions of The Bahamas and the other Caribbean nations who protect sharks within their waters, more work is needed on a regional basis in order to effectively manage many of these economically important species which call the entire North West Atlantic and Caribbean home.”

Sharks play a vital role in the Caribbean, both to the health of the ocean and to a countless number of people whose livelihoods are directly connected to these animals.  With at least 100 million sharks killed each year, establishing additional meaningful and lasting protections in the Caribbean will ensure a healthy shark population for future generations.

Stingrays: Whiptail Genetics

Volunteers Dan and Stand Displaying the tow highly agile and toxic barbs from a juvenile whiptail ray from Samson Cay Recently, the Cape Eleuthera Institute’s Stingray Research Group mounted its final expedition to remote cays in the Exumas Islands, to finalize the collection of genetic information from the rare, elusive and recently ‘re-discovered’ Caribbean whiptail stingray, Himantura schmardae. Led by Dr. Owen O’Shea, the team comprised of interns, Rob Hallinan and Miguel Furtado, Newcastle University Graduate Student, Dan Montgomery and Education Program leader, Stan Burnside. The aim of this particular study is to assess the genetic connectivity of this batoid across multiple spatial scales, yet restricted temporal scales. Therefore, generations of parentage and sibling relationships are examined, rather than analyzing the connectivity through an evolutionary perspective.

The smallest whiptail of the trip, seeking shelter in isolated tidal pools of Banshee Creek, Warderick Wells

After crossing the Exuma Sound, the team first arrived at Little Creek in Guana Cay where the first whiptail stingray was located – a tiny female in shallow water as the tide ebbed. A further three more were sampled from Sampson Cay to the north, making the first day a success. The team was able to select their very own island for the night’s camping before readying the equipment for day two of three. The second day was even more successful; the team found and caught eight of these stingrays as they continued to move north. Three were found in the mangroves of Pipe Cay, two within the Compass Cay marina, and three found from a dry creek at Warderick Wells Cay. The little rays were the smallest of the project so far (228, 229 and 232 mm wide) but were also located in very small, very hot tidal pools scattered throughout a desert dry Banshee creek. Day three was more challenging as the team investigated several creeks from Shroud and Hawksbill Cays, that appeared promising, indicated by the presence of dozens of ray feeding pits. However, no whiptails were seen. With only two samples left to meet the minimum requirement for sample size, the team explored the flats of Highbourne Cay and the mouth of Ship Channel Cay where three more whiptail stingrays were sampled, and therefore bringing the total for the trip to 15, five more than our target.

Banshee Creek, Warderick Wells- there are two tiny whiptails in this tidal pool!

This study is the first sine 1968 to document this species of stingray in The Bahamas, and a manuscript detailing their contemporary distribution in The Bahamas is currently under review. Now, with genetic information pertaining to 68 individuals sampled throughout the course of this study, spanning from Hummingbird Cay in the southern Exuma Cays to Hartford Creek, in the east end of south Eleuthera, Dr. O’Shea and his team can begin to analyze the relative relationships among these stingrays and determine their connectivity, along with possible migratory corridors, adding to the paucity of information not only about this species, but the habitats that support them. Interestingly, on this voyage, no mature stingrays were seen, potentially indicating a partitioning of spatial resources between juveniles and adults. Where juveniles were more often seen in shallow creek systems, larger adults tended to occupy areas of deeper water, potentially highlighting the importance of creeks as nursery grounds for juvenile Caribbean whiptail stingrays. Continuing this research this summer, Dr. O’Shea will begin to assess the significance of these shallow, warm-water creek systems on the life-history of these juvenile Caribbean whiptail stingrays.

Lionfish Day and Jewelry Workshop with The Blue Seahorse

On Saturday, May 7th, the Reef Ecology and Restoration team at the Cape Eleuthera Institute (CEI) partnered with The Blue Seahorse gift shop in Rock Sound for a day of lionfish festivities. The afternoon was centered around different crafts and foods people can make with this invasive species. Delicious lionfish burgers were served at The Blue Seahorse and the reef team was able to demonstrate different aspects of lionfish research by teaching how to dissect and properly fillet a lionfish while handling the 18 venomous spines. A main goal of the reef team is to debunk the myth that lionfish are poisonous or deadly. The team even brought a live lionfish in a display tank to show how lionfish use their pectoral fins to herd juvenile fish for consumption. Reef team members Helen Conlon and Pauline Navaez educate visitors about invasive lionfish, how to properly fillet them, and how their fins can be used for jewelry. Photo courtesy of The Eleutheran.

Along with the current threats posed by the lionfish in the Caribbean, visitors also learned about the use of the beautiful lionfish fins for jewelry. Customers were even able to purchase lionfish earrings and necklaces that artist and owner Holly Burrows made. On Thursday, May 19th, Holly came down to CEI to host a lionfish jewelry making workshop. Participants picked their fins, taken from harvested lionfish, and with the guidance of Holly created beautiful sets of earrings and necklaces. Lionfish jewelry is a fantastic way to profit from the invasion, while also helping to create a demand for lionfish--and not to mention makes for a great gift for loved ones.

Lionfish earrings made by Helen Conlon during the jewelry workshop put on by Holly Burrows.

Invasive lionfish in the Caribbean have a spawning rate of 30,000 eggs every four days, while having no predators in their invasive range. They also have the potential to reduce the abundance of fish on a reef by over 80%. The Slayer Campaign, established by CEI, encourages the fishing and spearing of lionfish by local fisherman by paying fishermen for their catch efforts ($11/lb of lionfish fillet). Removing lionfish from local reefs not only benefits the coral ecosystem but, also provides CEI and the reef team with more lionfish to dissect for research. Discussing and displaying this ongoing research and effort with tourists and locals made lionfish day at The Blue Seahorse a huge success!

 

Sea turtle adventures in Savannah Sound with Fishbone tours

Last week the CEI Sea Turtle Research Team had the opportunity to collaborate for the third time with Julius Rankine, who operates Fishbone Tours in Savannah Sound. Julius offers interactive expeditions including fishing, snorkeling, and learning about local wildlife conservation. For the last six years, he has also offered a turtle catching experience, contributing data to our sea turtle database. After hundreds of turtle chases, he has gained extensive knowledge of the turtles’ habitat and behavior, and the best ways to catch them. The sea turtle team and Julius aboard his boat in Savannah Sound.

Our day was spent getting to know the area, learning about where each species of turtles can be found, and practicing the Bahamian method of catching a turtle. Julius was entertained by our official method of jumping off the side of the boat and swimming after the turtle, but didn’t think we would ever catch it. Instead, members of the team tried diving off the bow to get our hands on the turtle when they came up for air to avoid the tiring swim. The team caught and tagged eight new green sea turtles with his method, but the ninth proved too smart to let the boat get close. Finally, one of our interns jumped in the water, swam, and dove to capture the individual, proving that sometimes it takes more than one method to catch a turtle.

Interns prepare to tag one of the nine new juvenile green sea turtles.

Julius was able to teach us a great deal about Savannah Sound and the local turtle populations, while we shared more of our methods and research background with him.  Tagging in Savannah Sound would present the opportunity to catch a new group of green sea turtles, as well as hawksbills and loggerheads, which are much more rarely caught and tagged around Eleuthera.