Category Archives: Research Programs

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)
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
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)
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!

 

Sea Turtle team supports the Bahamas National Trust summer camp

On Thursday, July 28th representatives from the sea turtle research team at CEI went to the Leon Levy Preserve in Governor’s Harbour to share their knowledge about sea turtles with 30 Bahamian children attending the Bahamas National Trust Camp Safari. The week focused on herpetology and during a morning block the CEI team taught the campers about sea turtles. A presentation explained the 4 different species found in The Bahamas – green, loggerhead, hawksbill and leatherback – as well as about their life cycle and some of the threats that these reptiles are facing as well as some conservation measures that are helping restore populations.

Research Technician, Anna Safryghin, teaching kids at Camp Safari about sea turtles.
Research Technician, Anna Safryghin, teaching kids at Camp Safari about sea turtles.

The campers were very interested and particularly enjoyed videos of sea turtle hatchlings crawling towards the sea.  After the slide show presentation everyone participated in an activity where the campers had the chance to practice their sea turtle identification skills, by realizing two dimensional models of the 4 species of sea turtles, as well as learn some important facts about their diet and habitat. During the whole event, the kids were very excited to learn and had many questions. This opportunity for outreach and education was very successful and we are grateful to the Bahamas National Trust for inviting us to join in the camp.

Kids testing their sea turtle identification skills
Kids testing their sea turtle identification skills

Newcastle University Summer Research Update

Globally, sharks are among the most threatened group of species, facing some of the greatest population declines in modern history. This is exacerbated by conservative life history characteristics such as slow growth rates, late maturity ages and low number of offspring, which in turn increase their vulnerability to extinction. Turtles also exhibit similar life history characteristics, therefore assessing their importance as a food source and the significance predation has on their population can help us to further conservation efforts. This summer, Newcastle University student Massimo Casali in collaboration with the Cape Eleuthera Institute’s Shark Research and Conservation Program has been conducting a study to elucidate the importance of habitat complexity and coastal shark species on turtle abundance in different creek systems. The Bahamas offers unique opportunities to study turtles and sharks on account of a total ban being enforced since 2009 and 2011 respectively, and so this project will take advantage of the relatively untouched environment of south Eleuthera, The Bahamas.

Newcastle University undergraduate student Massimo Casali holding a nurse shark prior to release
Newcastle University undergraduate student Massimo Casali holding a nurse shark prior to release

Through the use of experimental longlines, sharks are caught in close proximity to creek systems before being sampled, including the taking of morphometric data (measurements), tissue harvest for stable isotope analysis and tagging, allowing for mark-recapture assessment. So far the team has caught a total of 21 sharks represented by 5 species; nurse shark (Ginglymostoma cirratum), Caribbean reef shark (Carcharhinus perezi), blacknose shark (C. acronotus), blacktip reef shark (C. limbatus) and tiger shark (Galeocerdo cuvier). This research has also included a range of educational programmes and Island School classes enabling us to reach a broad range of budding young shark scientists.

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A nurse shark (Ginglymostoma cirratum) being measured.

Overall, the research objectives of this study will form the basis for Massimo’s undergraduate research dissertation, that will specifically address the relationships between sea turtle and shark abundance in these biologically diverse ecosystems, considered fragile due to human induced disturbances. This will further allow conservation frameworks that will allow the management of sensitive coastal ecosystems throughout The Bahamas.

South Eleuthera offers the only mangrove creek systems on the Island - here shows Kemps Creek which borders the Grand Bahama Bank.
Kemps Creek which borders the Grand Bahama Bank.

American Elasmobranch Society meets in New Orleans

The American Elasmobranch Society recently met in New Orleans for their annual meeting, attended by an international collective of shark and ray scientists to discuss current and ongoing work in this very eclectic field. The Cape Eleuthera Institute was represented by Oliver Shipley and Dr. Owen O’Shea of the Shark Research and Conservation Program, both giving oral presentations to a wide range of scientists from all over the world. Oliver’s presentation focused on novel methods for post-capture release of a small bodied deep-sea shark – the Cuban dogfish – and how novel approaches may increase survivorship during by-catch events. Owen spoke of the recently ‘re-discovered’ Caribbean whiptail stingray and discussed its contemporary distribution in The Bahamas and implications for management.

Dr, Owen O'Shea during his presentation on Caribbean whiptail stingrays
Dr. Owen O’Shea during his presentation on Caribbean whiptail stingrays

The week spent in New Orleans was a huge success, with the convening of several meetings and discussions pertaining to the global fin print project and a whole day dedicated to a global sawfish research symposium. Among some of the other stand out talks were the very first satellite tracking of manta rays conducted in Sudan, juvenile white shark movement in California and challenges for management of large ranging sharks, such as the great hammerhead and oceanic whitetip. It was a fantastic week with many old relationships rejuvenated, and the fostering of new ones cemented, with collaborative studies already having been discussed.

Operation Wallacea

During the course of a six-week program, three students representing Operation Wallacea (Marcus Griffiths of the University of Nottingham, Rob McCalman of the University of Portsmouth and Lucy Arrowsmith of the University of Cardiff) have teamed up with Dr. Owen O’Shea at The Cape Eleuthera Institute to investigate the benthic habitat diversity of various creek systems around Eleuthera, The Bahamas. This project aims to establish the relationships between environmental and physical characteristics of the recently ‘re-discovered’ Caribbean Whiptail Stingray, Himantura schmardae.  As a meso-predatory species, these stingrays provide an important link between apex predators and the benthic organisms they prey upon. An abundance of this species within creek systems provides a good indication of ecosystem health.

The Ray team surveying Deep Creek - A very large and biologcally rich ecosystem bordering the deep Exuma Sound
The Ray team surveying Deep Creek – A very large and biologcally rich ecosystem bordering the deep Exuma Sound

The team are currently in the process of completing benthic habitat analysis on four sites: Deep and Wemyss Bight Creek (Atlantic/Exuma Sound) and Kemps and Starved Creek (Grand Bahama Bank). This project is collecting data using a 1m2 quadrat to assess the percentage cover of flora and fauna species found in these locations, so far completing a total of 274 quadrats over a 2.6Km2 combined study area. In addition, sediment cores; sediment depth; water salinity; dissolved oxygen and water temperature are being collected at each location to gather a broader insight into the habitual preference of juvenile Himantura schmardae that appear to be utilizing these creeks on a long term basis.

The Caribbean whiptail stingray - specimen from Deep Creek
The Caribbean whiptail stingray – specimen from Deep Creek

The aim of the investigation is to determine the relationship between the creek environments and the presence or absence of this relatively elusive stingray. Additionally the morphological, sexual and feeding characteristics will provide insight into the potential role of these marine systems as possible nursery sites. As a relatively new re-discovery for The Bahamas, this research could provide critical information towards development of successful conservation plans, and fine-tuning the coverage of marine protection areas (MPAs) as declared by The Caribbean challenge for the Bahamas in 2008.

Kemps Creek on the Banks side - a smaller, mangrove fringed creek
Kemps Creek on the Banks side – a smaller, mangrove fringed creek

Flats team picks up acoustic receivers and finds elkhorn coral

Georgie Burruss secures a receiver to a cinderblock after downloading the data from the device.
Georgie Burruss secures a receiver to a cinderblock after downloading the data from the device.

Last week, the Flats Ecology and Conservation team downloaded data from a large-scale passive acoustic telemetry array designed to track bonefish to their pre-spawning aggregations. A total of 61 receivers were placed around Eleuthera to track the movements of 39 bonefish and 14 barracuda that were implanted with acoustic transmitters. The research team downloaded key receivers and found schools of bonefish moving over coral reef habitats at night near tidal creeks on the East coast of Eleuthera, indicating that these fish may move offshore to spawn on the windward side of the island. Stay tuned for more updates in June.

A healthy stand of Elkhorn coral
A healthy stand of Elkhorn coral
Helen Conlon signals okay after redeploying a receiver.
Helen Conlon signals okay after redeploying a receiver.

As a bonus, while collecting receivers the team got to swim by several Elkhorn coral (Acropora palmata) colonies, an IUCN-listed critically endangered species. Elkhorn coral grows rapidly, providing significant structure and habitat for reefs throughout the Caribbean, though it is in severe decline as a result of coral bleaching, predation, storm damage, disease, and human activity. Though it was heartening to see so many healthy colonies of this critically endangered species, they are small compared to the large stands of dead elkhorn that used to thrive in the area. Our reef restoration project has begun mapping these areas and will be monitoring its growth.

Patch reef survey time!

Last week the Reef Ecology and Restoration team completed the March monitoring surveys of the 5 year reef study around the patches of Eleuthera. The March surveys usually call for thick wetsuit, hoods and hot chocolate. However, the water was particularly warm at 27oC, resulting in the surveys being completed in record time. Dr Jocelyn Curtis-Quick has been leading this study since 2012; she now plans to use this incredibly unique and invaluable dataset to thoroughly examine the influences and impacts that the invasive lionfish have on the patch reef ecosystem.

Every part of the reef is searched for lionfish
Every part of the reef is searched for lionfish

The Reef Ecology team has already begun the process of analysis, and Jocelyn was able to present some of these preliminary findings at the Bahamas Natural History Conference in Nassau earlier in the month. By continuing to spread and enhance the local knowledge within Eleuthera and beyond, the management of the lionfish will hopefully continue to grow.

Removing lionfish from the reef
Removing lionfish from the reef

Of the 16 patches that have been surveyed throughout the study, 8 have been designated as removal sites, and with a highly experienced team we were able to continue our contribution to the culling effort around The Bahamas and wider Caribbean. Stay tuned to hear the full results of our study and a more detailed picture of how the lionfish is making its presence felt around Southern Eleuthera. In the mean time don’t forget, You Slay, We Pay!

Research to protect Eleuthera seahorses

Dr. Jocelyn Curtis-Quick and her team have been assisting Dr. Heather Masonjones with her ongoing seahorse research in Sweetings Pond. Sweetings Pond on the island of Eleuthera contains a diverse array of species, including both seahorses and octopuses. Originally described in the early 1980’s, this pond has remained unstudied over the past 30 years.

The amazing seahorses of the pond (photo credit Shane Gross)
The amazing seahorses of the pond (photo credit Shane Gross)

This type of tidal saltwater pond forms in regions with limestone geologic histories, fed from the ocean through cracks and underground caverns. Depending on the size of these connections and how long they have been isolated from gene-flow, these ponds are well known sites of speciation, with an array of endemic or limited-range organisms, and unfortunately, a long list of species declines. The Sweetings Pond site is part of wider assessment of the inland ponds found all over Eleuthera, led by Dr. Jocelyn Curtis-Quick.

All seahorses found are photographes as their marking can be used to identify individuals
All seahorses found are photographes as their marking can be used to identify individuals

Seahorses are marine fish that have captivated humans for generations. Worldwide, their populations are under threat from over-harvesting for curios, traditional medicines and as bycatch from fisheries. They are also declining because of decreasing water quality of their shallow coastal habitats, and increased use of these habitats through poorly-managed tourism. The impacts of these threats are difficult to measure in seahorses, because they are difficult to study in the wild.  The pond species of seahorses, Hippocampus erectus, is also listed as Vulnerable on the IUCN Red List, an international organization dedicated to conservation.

At night a black light shows the tagged fish (photo credit Shane Gross)
At night a black light shows the tagged fish (photo credit Shane Gross)
Lili Wagner finds a baby octopus on the light trap
Lili Wagner finds a baby octopus on the light trap

The team spent two days assessing the seahorse’s use of different habitats and successfully tagged more than 30 seahorses, enabling the mark and recapture technique to be used to assess population density. In order to assess what the seahorses are eating, as there is little to no research on their prey selection at night, the team set out plankton tows and executed gastric lavage procedures on the seahorses. The stomach contents were preserved and will be sent to a lab at the University of Tampa to be analyzed, and the animals were released unharmed back to the exact location where they were originally found. Because of their monogamous mating system, moving animals from their home location can interrupt mating pairs, and make it difficult for animals to reproduce.

Populations of seahorses are rarely as dense as we have measured in the pond, so from a conservation perspective, this would be an excellent choice of location to protect and conserve for future generations.  Dr. Masonjones presented the preliminary findings at the Bahamas Natural History Conference last week.

If you see seashores in the water around Eleuthera please report your sightings on iSeahorse.

Professor Wicksten visits CEI

Prof. Wicksten exploring the inland ponds
Prof. Wicksten exploring the inland ponds

The Reef Ecology and Restoration team welcomed Prof. Mary Wicksten to CEI last week. Prof. Wicksten is a professor at Texas A&M University, College Station, where she works on the biogeography, systematics and behavior of decapod crustaceans. Prof. Wicksten is collaborating with CEI’s Dr Jocelyn Curtis-Quick on the anchialine pond research.

Rare shrim found in the ponds of Eleuthera. Photo credit: Drew Hitchner
Rare shrim found in the ponds of Eleuthera. Photo credit: Drew Hitchner

During Prof. Wicksten’s visit, she got to explore some of the inland ponds and helped to identify deep sea crab species for other researchers at the institute. Prof. Wicksten used her expert ID skills to also identify crabs and shrimp present in the stomach contents of some lionfish. Prof. Wicksten had the opportunity to talk with the young ones from the ELC about crustaceans – inspiring future scientists!

Although a short visit to the CEI, Prof. Wicksten made the most of her time, and even helped to support the ongoing lionfish outreach.  She attended the Blue Seahorse art show, where the Reef Ecology team was increasing lionfish awareness, particularly the importance of removing the lionfish from the reefs and spreading the word that it is a really good fish to eat!

It was a pleasure to have Prof. Wicksten with us for four amazing days!

Queen conch “graveyard” study taking place at CEI

An adult conch in the shallow water
An adult conch in the shallow water

High on top of the Bahamian crest is a queen conch—an iconic representation of how truly integrated marine ecosystems are to Caribbean culture. Queen conch (Strombus gigas) is a large gastropod native to the Caribbean and has been a staple in the Bahamian diet for centuries.   Unfortunately, the overfishing of conch has caused massive declines in populations, and conservation efforts are greatly needed to promote a healthy and sustainable conch fishery in the Bahamas.

Selecting conch at random to  be used in a trial
Selecting conch at random to be used in a trial

In fisherman lore around the Bahamas it is said to be bad luck to throw knocked conch into the water, as it will scare away living conch—thus, huge conch middens are often found onshore. But, some conch are still tossed overboard at sea, and it is thought this may also be affecting conch populations. The Sustainable Fisheries team, here at the Cape Eleuthera Institute (CEI), is testing avoidance behavior from conch with help of several Island School students. The main question is- do conch flee upon seeing/smelling an injured or dead conspecific, and if so, what sort of cue is triggering movement?

Sustainable Fisheries intern Cara measures the distance moved by a conch in a behavioral trial
Sustainable Fisheries intern Cara measures the distance moved by a conch in a behavioral trial

So far 40 trials have been conducted, and CEI’s Claire Thomas, Program Manager for Sustainable Fisheries, will be presenting the preliminary results at the Bahamas National Trust Natural History Conference in Nassau this week. As we conduct more trials and gain more insight into potential conch avoidance behavior, there may be implications for new management strategies to better protect this important species—stay tuned for results!