Category Archives: Research Programs

Dr Owen O’Shea visits the Florida Fish and Wildlife Conservation Commission

The ongoing collaboration between the Cape Eleuthera Institute and the Florida Fish and Wildlife Conservation Commission (FWWCC) was recently further endorsed with a visit by Research Associate Dr Owen O’Shea to the FWWCC headquarters in St. Petersburg, Florida. Much of Dr O’Shea’s work on stingray genetics is in collaboration with Dr Liz Wallace, postdoctoral research fellow at the commission and so this trip served as an analytical opportunity for Owen to conduct lab work with Dr Wallace in order to process DNA samples collected over the past 12 months.

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This research project is in the final stages of completion, after Owen collected 70 samples from the rare, elusive and recently re-described Caribbean whiptail stingray Styracura schmardae across multiple spatial scales in the central Bahamas. This work is the first of its kind in this species, and will attempt to discern dispersal potential and gene flow across restricted temporal periods, for example, in assessing sibling and parentage relationships, rather than an historical radiation.

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This work is important, because in fragmented habitats, such as The Bahamas, barriers to gene flow and dispersal are realized, particularly among island chains, separated by deep ocean basins. This provides challenges for live bearing fish species, further exacerbated by conservative life histories; so understanding these dynamics and potential migratory corridors will enable us to further discern the importance of these coastal environments.

Prey discrimination in yellow rays: project update

In the last month, Research Technician Maggie Winchester began behavioral trials of yellow rays (Urobatis jamaicensis) as part of her independent project, under the supervision of Dr. Barbara Wueringer of James Cook University, Australia, and Dr. Owen O’Shea of the Cape Eleuthera Institute (CEI). This project aims to address the capacity of the electric sense utilized by all elasmobranchs, as it pertains to their foraging strategy. Specifically, Maggie and the team using experimental manipulations to assess to what extent prey type can be ‘discriminated’ by isolating electric sensory mechanisms alone.

Yellow ray close up
Yellow ray close up

The yellow ray is one of the most ubiquitous and commonly encountered elasmobranchs throughout the Caribbean region and is a regular visitor to the shelf and patch reefs adjacent to CEI. It is a small-bodied benthic ray that lives in seemingly mixed sex aggregations and is very easy to catch in shallow water with two dip nets by snorkeler. So far, the team has successfully captured and transported 19 rays to the wet lab at CEI, where they have all undergone behavioral trials, and been successfully returned to their capture sites after 24-hours observation.

A yellow ray in one of our wet lab holding tanks awaiting trails
A yellow ray in one of our wet lab holding tanks awaiting trials

During the experimental trials, individual rays are presented with two concealed prey types that are known to be part of their diet based on a study by CEI currently in review for publication. These two prey choices are concealed in agar, masking visual, chemical and gustation cues and allowing for detection solely through electro-sensory means.

This work will allow a clearer and more concise evaluation on the specific role the ampullae-lorenzini have in discriminating a specific type of prey, and raises questions on whether these rays actively choose one prey type over another.

The return of old friends

It’s been an exciting time for the shark team at the Cape Eleuthera Institute with 2 tagged sharks recaptured over the past few weeks. The team has been conducting frequent long line surveys to collect information about the species, sex and size of the sharks that inhabit the waters around Eleuthera. DNA, blood and muscle samples are also collected from each shark to build up a wealth of biological data which can be used for more in depth studies in the future.

Research technician Maggie Winchester inserts a dart tag into the dorsal fin of a Caribbean reef shark with the help of Dr. Heather Marshall
Research technician Maggie Winchester inserts a dart tag into the dorsal fin of a Caribbean reef shark with the help of Dr. Heather Marshall

CEI tags all of the sharks that are caught on their longlines with 2 different kinds of tags, a dart tag and cattle tag, which assign an individual tag number to each shark. This not only allows the shark to be easily recognized by the shark team, but also shows other people that these sharks have been caught and sampled by CEI. The tags provide the CEI contact details to allow other research stations or fisherman that may catch the shark to report its location. This recapture data allows the team to analyze distribution behaviors and track the movement of the sharks around Eleuthera.

The most recent recapture was of a female Caribbean reef shark (Carcharhinus perezi) which was caught on the 31st of October, only 300m away from where it was first caught in April 2010. Over the past 6 years this shark has grown by nearly half a meter and now measures a total length of 178cm. A few weeks earlier, on the 12th of October, the team caught a large female nurse shark (Ginglymostoma cirratum) that had not been seen since it was first tagged nearly 8 years ago. This shark had only grown by 3cm over this time but was recaptured nearly 6km away from where it was originally caught and tagged.

A Google Earth satellite image showing where and when the 2 sharks were originally caught and recaptured
A Google Earth satellite image showing where and when the 2 sharks were originally caught and recaptured

Using species-specific size at maturity data, the team can use the total length measurements of these 2 recaptured sharks to estimate that both sharks have recently reached sexual maturity. This is particularly important information when considering the local populations of these sharks as they are now thought to be of reproductive age. These resident sharks will remain around the Cape and contribute to local populations by giving birth to several pups in the mangrove creeks surrounding Eleuthera.

School Without Walls

Over the past two weeks the CEI Sea Turtle Research and Conservation team has had the opportunity to join forces with the grade 7 and 8 classes of Deep Creek Middle School (DCMS). The grade 8 students have been studying the Lucayans in both their Art and Social Studies classes. In Social Studies the students were learning about the turtle-catching techniques of the Lucayans. The Lucayan method involved tying string to remoras and once the remora has found and attached itself to a turtle the Lucayans would catch it and bring it onto land. In their art class they took inspiration from the turtles to create a Lucayan style art piece. The grade 8 students met up with the turtle team in Deep Creek and learned how to capture, handle and measure juvenile green sea turtles.

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Grade 8 students search Deep Creek for a turtle to chase

The class broke up into several groups and went out on a small boat to search for turtles within the creek. Once a turtle was spotted one person would keep their eyes on the turtle and point at it while everyone else got their snorkel gear on and ready to go. After the turtle came up to breath a few times swimmers were sent in to chase after the turtle and grab it when it came up to breath.

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A DCMS students proudly holding a turtle with his social studies teacher

The following week, the grade 7 class was given a presentation about sea turtles and then came out to Starved Creek to take their turn at chasing turtles as part of the School Without Walls program at DCMS. One of the goals of the School Without Walls program is to get students outside and learn about their environment. The students had the opportunity to hold, measure and chase juvenile green sea turtles as well as learn about the importance and significance of seagrass. The students were very excited to name the turtles tossing out names like Marshmallow, Steve and Diamond!

This partnership between DCMS and the turtle team was a huge success! The students got the opportunity to learn about sea turtles and CEI was able to expand its outreach efforts!

European Elasmobranch Association meets in Bristol

Over the weekend of the 28-30th October the European Elasmobranch Association met for its annual conference hosted by The Shark Trust in Bristol, England. Daniel Montgomery, a graduate student with Newcastle University, attended the conference to present his research focussing on the influence of temperature on habitat use of southern stingrays. This research was conducted at the Cape Eleuthera Institute between February and June 2016 in collaboration with Dr. Owen O’Shea and formed a research class for the spring 2016 Island School semester.

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The conference was attended by 160 delegates from 22 countries. Over the three days 67 oral presentations were delivered on a variety of themes with talks giving an overview of current research being conducted around the world. The conference is known for its broad focus with notable presentations ranging from taxonomy and isotopic analysis of deep sea sharks to the classification of nursery habitats in tropical mangroves.  In addition keynote addresses were delivered on subjects focusing on improving management and conservation of elasmobranchs globally. The conference gave a fantastic opportunity to meet other shark and ray researchers and promote the important work conducted at the Cape Eleuthera Institute alongside other research institutes.

Dan has just been awarded a pass with distinction from Newcastle University for his thesis titled Temperature preference and thermal niche of the southern stingray (Dasyatis americana) in South Eleuthera, The Bahamas. Dan is currently working towards his PhD at Exeter University and we wish him every success!

Graduate student update from the Stingray Research Group

Molly Meadows and Ethan Wrigglesworth have joined the team as part of the Masters of Research data collection from Exeter University in the UK, under the supervision of Dr. Owen O’Shea and Dr. Lucy Hawkes. The university has been visiting CEI every January for three years as part of their field course module, creating a fantastic bond between the two institutions. So it is very exciting to have students from Exeter studying their Masters with CEI for the very first time, further expanding our relationship and connection.

Ethan, Molly and the stingray team work up a large female southern stingray.
Ethan, Molly and the stingray team work up a large female southern stingray.

Both Molly and Ethan are researching stable isotope analysis on the two species of stingrays here in Eleuthera, the Caribbean whiptail and southern stingrays. Stable isotopes can be used to peek into the diet and ‘trophic status’ of an organism over different timescales. It basically follows the general rule of “you are what you eat”; all organic tissue has an isotopic value and, once ingested, that value can then be identified within the consumer’s body tissues. They will be collecting body tissue samples from both species of stingray, as well as diet and habitat samples, all of which will be analysed back at Exeter’s facilities in the UK. They will also be studying captive rays in the wet labs here at CEI, discerning how quickly isotopic values from manipulated prey sources are assimilated into different body tissues.

Molly and Ethan brief an educational program before going out into the field (Photo by Catherine Argyrople)
Molly and Ethan brief an educational program before going out into the field (Photo by Catherine Argyrople)

This research forms part of The Island School Applied Scientific Research Class and students will be directly assisting with data collection whilst producing a side project on dietary partitioning between the two ray species.Stingrays are remarkable, ancient creatures, which play key roles as mesopredators and bioturbators within their environment, keeping ecosystems stable and healthy. Despite this, not much is actually known about this group of around 90 species, particularly the species focused on in this study. Therefore, any research on these creatures is vital, not only for the conservation of the individual species, but for the systems they inhabit as a whole. Understanding these stingrays place in the food chain will help quantify their impacts on local fisheries and ecosystems allowing more effective conservation methods to be employed.

A female southern stingray is released after being sampled for stable isotopes
A female southern stingray is released after being sampled for stable isotopes

 

CEI shark team pulls in rare catch!

On Wednesday, August 31, 2016, the CEI Shark Research and Conservation Team caught and sampled a huge 258 cm male lemon shark (Negaprion brevirostris). This thrilling capture was made while conducting a longline survey off of Cape Eleuthera, Bahamas to establish a dataset about the abundance and size of different coastal shark species in south Eleuthera.  Although a wide variety of sharks can be found around the Bahamas, and there are many known lemon shark nurseries, mature lemon sharks are not commonly seen near south Eleuthera. The information collected from this rare catch can be used to trace the lineage of lemon shark populations found throughout the Bahamas, which can ultimately help influence future shark conservation and management initiatives.

Research Tech Maggie Winchester holds a 258cm long lemon shark in tonic immobility.  This allows the team to take measurements and samples, as well as tag the animal in a manner that is safe for both the shark and the researchers
Research Tech Maggie Winchester holds a 258cm long lemon shark in tonic immobility. This allows the team to take measurements and samples, as well as tag the animal in a manner that is safe for both the shark and the researchers

Lemon sharks are a large species of coastal shark that can reach up to 3.5 m in length. They can be identified by their pale brown or olive coloring, and their two equally sized dorsal fins.  Lemon sharks are listed as Near Threatened and their position at the top of the food chain makes them a valuable species for the local ecosystems. However, there is a limited amount of data on these adult sharks in this area which makes this catch all the more exciting. The Bimini Biological Field Station fills this knowledge gap by reconstructing adult male genetic information using the samples from the more abundant juveniles. Now we can include the data collected from this individual to create a more complete understanding of the local lemon shark population.

The team holds the lemon shark in tonic immobility so Dr. Heather Marshall can take a blood sample
The team holds the lemon shark in tonic immobility so Dr. Heather Marshall can take a blood sample

During the workup procedure, the lemon shark was measured to obtain information about its size, age, and sex, which can then be added to the data collected by CEI to show the dynamics of the local populations of sharks. The size of the shark was recorded by taking three specific measurements of its body. The team also collected a tissue sample, which will be used to build up a long term genetic record of the shark populations around Eleuthera. After all measurements and samples were collected, the lemon shark was tagged using a dart tag and a dorsal tag. These tags are used for identification purposes, allowing the research team to recognize a recapture. Following the workup procedure, the lemon shark was released in great condition and everybody was left in awe as it swam away.

The team is preparing to release the lemon shark by removing the hook so the researchers can effectively release the shark quickly and safely
The team is preparing to release the lemon shark by removing the hook so the researchers can effectively release the shark quickly and safely
The team watches the lemon shark swim away after a successful capture and release
The team watches the lemon shark swim away after a successful capture and release

CEI team visits with Space 2 Create summer camp

Last week, four members of staff from Cape Eleuthera Institute (CEI) visited Harbour Island as part of an outreach event working with the summer camp Space 2 Create.

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Space 2 Create is a comprehensive summer enrichment program that hosts 83 students for 3 weeks. Through artistic, academic and community projects, youth are empowered as leaders. During morning session students focus on one of the following tracks;

  • Space 2 Learn – math, English, science
  • Space 2 Taste – culinary
  • Space 2 Explore – marine science
  • Space 2 Tell your story – film making

The CEI team spent two days teaching and interacting with the camp participants exploring different aspects of research and science.

The first day Anna, Research Technician at CEI, gave a presentation about sea turtles in The Bahamas. The group learned about the four species of sea turtle in The Bahamas, and the threats they face. They also learned about their conservation status and the research being conducted currently at CEI. Following the presentation, the excited young students were able to go out in the field and participate in the capture of a green sea turtle contributing to the data they learned about earlier in the morning. They watched enthusiastically as measurements were taken and data was collected, and at the end of the workup were able to name and help safely release the animal. Green sea turtles are the most abundant of all 4 species found on Eleuthera, and are the main focus on the research conducted at CEI. Therefore the measurements taken from the turtle will allow researchers to gain important information such as growth rates and a health estimation of the individual, and contribute to a better understanding of the population of juveniles green sea turtles around Eleuthera.

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The team was invited to stay for the remainder of the day to learn more about Space 2 Create and join in some of their afternoon activities. The afternoon was spent singing, dancing, painting, and joining in the drama class.

The following morning, the focus switched to the status of sharks in The Bahamas. Shane Gross, photojournalist specializing in underwater conservation photography, gave an insightful talk on sharks using many of his own photos and experiences. After this, Maggie Winchester, Research Technician at CEI, gave a presentation on the shark research currently going on at the institute, followed by a Cuban dogfish dissection.

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Sharks play a significant role in the marine ecosystems of The Bahamas, not only improving ecosystem health but aiding the tourism industry as well. Despite their importance, many species of shark remain vastly understudied. The Cuban dogfish is an abundant yet poorly understood species of deep water shark in The Bahamas, commonly found at around 600m depth. During the dissection, the campers learned about the internal and external adaptations that make this small species of shark able to survive and thrive deep in the water column. This provided a hands on opportunity to learn about shark biology, using a species commonly found around the Cape.

Between Shane and Maggie’s talks and the interaction with the Cuban dogfish, myths about sharks in the Bahamas were addressed and resolved, and many fears were removed.

In the future CEI will work in collaboration with Space 2 Create and Bahamas Plastic Movement to support research activities for Eleutheran Eco Schools Club ‘s.

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Photo credit: Shane Gross

Summer internships a success!

(From left) Camila Mirow, Madeline Doten, Lillian Ganske, Josh Ratay
(From left) Camila Mirow, Madeline Doten, Lillian Ganske, Josh Ratay

The sea turtle research program welcomed four interns to the team this summer. Arriving June 20th, the interns worked hard both in the field and in the lab for 8 weeks learning the research protocols and getting to know the three Earthwatch teen groups that helped gather data over the summer. All four interns had an amazing time gaining hands on experience tagging and handling sea turtles and working with seagrass surveys and habitat mapping.

Interns and an Earthwatch team seining for turtles in Wemyss Bight
Interns and an Earthwatch team seining for turtles in Wemyss Bight

Camila Mirow (far left) is 19 years old. Despite growing up in Miami, she chose to move up north to study marine biology. She is now an undergraduate student in biological sciences at Mount Holyoke College where she is also completing a certificate in coastal and marine sciences. When Camila has free time she can be found surfing, SCUBA diving or exploring the island.  Camila’s trip to the Island School as an EP in 2015 changed her life and she knew that she had to come back, and here she is! She was so excited to be a part of the IS and CEI community and so grateful for this opportunity.

Intern Camila holding a Green Sea Turtle while biopsies are being taken for genetics and isotope research
Intern Camila holding a Green Sea Turtle while biopsies are being taken for genetics and isotope research

Madeline Doten (middle left) is 18 years old from Orlando, FL. She is going to be a sophomore at Furman University in Greenville, SC studying Biology on the pre-medicine track. Madeline was an Island School Summer Term student in 2014 and is so excited to be back on Eleuthera! In her free time she enjoys scuba diving, freediving, volleyball Tuesdays, and helping out with other projects at CEI and The Island School. Madeline enjoyed gaining field experience, meeting new people, and exploring more of Eleuthera this summer.

Sea Turtle research interns and volunteers helping pull the seine net
Sea Turtle research interns and volunteers helping pull the seine net

Lillian Ganske (middle right) is 19 years old and from Cleveland, Ohio. She is a rising Junior at Colgate University in upstate New York, majoring in the natural sciences with a concentration in marine and freshwater topical science. Her interest in the ocean began when she was on Eleuthera as an Island School student for the Fall 2012 term. She was excited to be back on the island after four long years to build on her previous research and fieldwork experience! In her spare time, Lilly could be found scuba diving, hiking, spending time on the beach, and going on run swims.

Josh Ratay (far right) is 20 years old and grew up in Kaneohe, Hawaii, where he acquired his love of the ocean.  He is now a rising junior at the University of Miami, majoring in marine science and biology, with minors in chemistry and ecosystem science and policy.  His previous field experiences include a semester abroad in the Galapagos Islands, fossil hunting, and wildlife tagging.  Josh enjoys snorkeling, freediving and SCUBA, as well as hiking, exploring and wildlife-watching. He has quite enjoyed his summer on Eleuthera!

Sea Turtle research interns and Earthwatch volunteers after a successful day of tagging in Winding Bay
Sea Turtle research interns and Earthwatch volunteers after a successful day of tagging in Winding Bay

Aside from assisting with our research, all four interns created and presented informative lectures on various topics including threats and diseases affecting sea turtle populations, foraging ecology of sea turtles, and prehistoric sea turtles! It has been a great summer working with these interns, and we thank them for all their help!

Studying the knowledge and consumption of lionfish on Eleuthera

Red Lionfish (Pterois volitans) is a venomous species that has been invasive to The Bahamas for over a decade (since 2004). It was first observed around Eleuthera in 2005 and has since become established around the island and its neighbouring cays. Research has shown that the impact of their invasion has and will continue to have detrimental impacts on marine habitats, especially coral reefs. Due to their voracious appetite and rapid reproduction (potentially up to 2 million eggs per year!), they have the potential to decrease commercially fished species’ populations and alter ecosystem processes e.g food webs. Their ability to do so has been aided by the naiveite´ (unfamiliarity with lionfish) of native fish and the fact that lionfish have no natural predators in Western Atlantic waters. As such, Cape Eleuthera Institute has promoted consumption of lionfish in an attempt to introduce it as a commercially consumed fish. This summer Newcastle University student Myca Cedeno has been conducting a social science study aiming to determine the spread of knowledge Eleutheran residents have on lionfish and consuming them as a means of managing their invasion and contributing to food security.

Diagram of a red lionfish clearly depicting its 18 venomous spines and general anatomy.
Diagram of a red lionfish clearly depicting its 18 venomous spines and general anatomy.

In April 2014, CEI introduced a Lionfish Slayer campaign, encouraging members of the public to spear lionfish in return for payment; a venture which was met with success. This summer Myca has advertised this campaign and worked to inform Eleutheran’s about lionfish’s nature as a “venomous” and not a “poisonous” species. Through interviews he has documented the views of the public on safely consuming this invader given their deleterious effects on the reefs. Myca has been in the field interviewing fishermen, restauranteurs and other members of the public as part of his dissertation research. His data collection is also coupled with educational outreach, as each interviewee is left with a flyer, detailing the history of the invasion, why it is safe to consume (despite its venomous spines), how to handle and prepare it and what to do if stuck by a spine.

Red lionfish (Pterois volitans), on a patch reef off Eleuthera, The Bahamas
Red lionfish (Pterois volitans), on a patch reef off Eleuthera, The Bahamas

So far, it’s nature as a venomous species has been a major deterrent to consumption for consumers and catch by fishermen. Restauranteurs have highlighted a lack of availability of the lionfish, potentially linked with the apprehension of fishermen to catch them. It is the hope that this research and outreach effort will help further educate the public as to the value of eating red lionfish and will provide insight as to how best to further promote this venture.