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.
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.
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.
As Hurricane Matthew made contact with the Bahamas in early October, it brought with it many threats of damage and devastation. The Cape Eleuthera Institute (CEI) was extremely fortunate in the sense that Matthew did not hit as hard as expected, but still the storm left its fair share of destruction. Coral reefs offer numerous benefits to ecosystems; one of these being that they can dissipate the power of storm waves generated by hurricanes and therefore lessen the blow of terrestrial damage. However, this absorption of wave energy does not leave the reefs unimpaired.
During large storm systems such as hurricanes, corals are susceptible to fragmentation. Fragmentation is a negative effect in the sense that it can cause some stress to the coral, but on the other hand it can be a positive event because some coral species, such as Elkhorn coral (Acropora palmata) and Staghorn coral (Acropora cervicornis) use fragmentation as a form of asexual reproduction. That is, a new colony can grow from a fragment of the parent colony. Scientists across the Caribbean, including here at CEI, are using this method of growth to create coral nurseries which grow fragments to be outplanted onto damaged reefs.
As CEI continues to focus its research on the endangered Elkhorn coral (Acropora palmata) in the wild, the Coral Team went out to assess the toll Hurricane Matthew had on our local reefs. As expected, there was a decent amount of fragmentation found at Bamboo Point, where there was a large colony of Elkhorn coral with evidence of recent storm damage. Some fragments seen nearby were due to Hurricane Matthew whereas others were older and likely produced by past events. It is CEI’s hope that the newly-formed fragments will proliferate to form new colonies.
In addition to fragmentation, hurricanes have been shown to relieve thermal stress. By mixing the water column and bringing water temperatures down, storms can once again restore favorable thermal conditions and allow coral the chance to recover from bleaching events. As climate change continues and sea surface temperatures rise, coral bleaching events have become more prevalent as the coral’s symbiotic zooxanthellae are expelled. Due to a number of stressors including climate change, overfishing and pollution, coral are increasingly vulnerable. Major storm events are beneficial only once in a while, but if there are too many large storms too often it not only makes the environment uninhabitable for corals, but also can permanently damage reefs that are already existing at the upper limits of their stress tolerance.
As the 2016 hurricane season comes to an end, CEI will continue its monitoring and restoration efforts of Eleuthera’s reefs in the hopes that we can continue to enjoy the many benefits they provide!
Last year, CEI’s Flats program, along with Georgiana Burruss, CEI Research Assistant, began a three-year study to identify critical bonefish spawning aggregation sites on Eleuthera, The Bahamas. Currently, six spawning aggregation locations have been identified in The Bahamas; one of which is located in South Eleuthera. This study aims to track bonefish populations across Eleuthera to fill this knowledge gap and identify critical habitat for this economically important species.
In year one, the team identified a number of potential bonefish spawning migration corridors in North Eleuthera, South Eleuthera, and along the East coast of Eleuthera. The team deployed 62 VEMCO acoustic receivers to track the movements of 39 tagged fish as they migrated away from known foraging grounds and tidal creeks. Bio-telemetry data indicated potential spawning migration corridors in the North East, South East, and East regions of Eleuthera. In addition, the team was able to track the nighttime movements of spawning aggregations in the South West region of the island. Although, transmitter detections in the North West part of the island were limited, data suggests this may be a result of timing coordinated with spawning-related movements in other regions, indicating that the detections were potentially spawning-related. Interestingly, bonefish tagged in each of the areas were not detected in another region, suggesting these populations are unlikely to mix. Overall, 5 migration corridors have been identified, with data suggesting that there are at least 5 bonefish spawning sites on Eleuthera, although further studies are needed.
Given the success of last year, the bonefish telemetry project officially kicked off its second year of data collection to answer the following questions:
Where are bonefish forming spawning aggregations in the 5 regions of interest on Eleuthera?
How do abiotic factors (season, moon phase, temperature, current, tide, etc.) influence bonefish spawning migrations in South Eleuthera?
What is the energetic cost of spawning migrations?
Two VEMCO positioning arrays were deployed to assess the broad and fine scale spawning migration movements of bonefish in Eleuthera. 42 receivers in the broad scale array were concentrated around zones of interest in each region (identified from last year’s study) to further the understanding of bonefish spawning migrations and staging areas. This increase in coverage combined with manual tracking and visual observations should provide further evidence and confirm our previously identified sites of interests as critical spawning areas. Transmitters will be implanted in 30 bonefish at strategic locations around Eleuthera allowing for the fine scale movements of these fish to be collected. Additionally, these fish will add to the existing 39 bonefish tagged last year to provide unprecedented data on these economically important species. By simultaneously tracking bonefish from several areas of Eleuthera, we can better determine which environmental cues bonefish use to form spawning aggregations, such as moon phase and tides.
At the previously identified spawning aggregation site of interest in South Eleuthera, 31 receivers were placed in an overlapping fine-scale array to track the movements of the bonefish aggregation on an almost continuous basis. This array will allow the team to answer questions related to: how abiotic factors (current, moon phase, seasonality, tide) influence bonefish spawning, how predators interact with the aggregation, understanding the energy expenditure of bonefish when migrating to their spawning site, and potentially the physical act of spawning which is yet to be described. Furthermore, the fine-scale array will fill critical knowledge gaps regarding the diel movements of tagged predatory species, such as great barracuda,Sphyraena barracuda, and blacktip shark, Carcharhinus limbatus. In addition to the basic positional transmitters being deployed, the team will be deploying 20 acoustic transmitters fitted with accelerometer sensors to determine energy expenditure of bonefish during spawning as well as 20 acoustic tags in predatory species to assess predator interactions with the bonefish spawning aggregation. Collectively, findings from this study will be used to develop a management and conservation framework for bonefish and predatory species of surrounding Eleuthera, The Bahamas.
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.
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.
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.
SECORE (SExual COral REproduction) International arrived at the Cape Eleuthera Institute last month for a week of research focused on coral spawning. SECORE is a non-profit organization dedicated to the restoration of coral reefs using wild coral spawn, lab-based fertilization and breeding techniques and outplanting methods. Led by Dr. Dirk Peterson (founder and CEO), Christoph Haacke (BioDivers, Germany), Mark Schick (Shedd Aquarium, USA), and Mitch Carl (Henry Doorly Zoo and Aquarium, USA), the SECORE team believes that in order to rehabilitate degraded reefs, increasing coral survival, diversity and abundance through lab-based breeding techniques is essential. Dr. Peterson began his innovative coral breeding techniques in 2002 by fertilizing coral spawn and raising larvae in a lab. The coral restoration community took notice of his successes, and SECORE has since led projects in locations such as Guam, Mexico, Curaçao, and The Philippines. With reversing the decline of coral reefs a national priority in The Bahamas, SECORE aims to bring its expertise here to Eleuthera, in partnership with CEI, to help with rehabilitation and restoration efforts.
The focus of SECORE’s work in Eleuthera is Elkhorn coral (Acropora palmata), a critically endangered species. Elkhorn coral spawning has rarely been documented in The Bahamas, but is known to occur elsewhere in the Caribbean after sunset, during the days following August full moons. As the week-long workshop began, SECORE aimed its efforts on diving after sunset in high-density areas of Elkhorn coral in hopes of not only documenting the exact timing of the annual spawning event, but also collecting egg and sperm for fertilization back in the lab. To the group’s delight, the timing was perfect. SECORE and CEI documented Elkhorn coral spawning in Eleuthera for the first time! In addition, SECORE collected approximately one to two hundred thousand eggs from four different coral colonies that spawned simultaneously.
To ensure ample genetic diversity among corals fertilized in the lab, SECORE collects eggs and sperm from multiple Elkhorn coral colonies. This diversity is essential for the survival of this endangered species, which can be threatened by a genetic bottleneck as populations decline. Once SECORE induced fertilization, larvae were placed in a breeding chamber for development. Live rock similar to that upon which wild coral larvae attach on natural reefs was introduced to the tanks, allowing lab-reared corals to become established as would their wild counterparts. CEI’s and SECORE’s collaborative goal is to give juvenile corals a head-start by providing a predator-free, controlled environment where survival is enhanced during critical early growth stages. Once juveniles have survived in the lab beyond those critical early stages, they will be strategically out-planted onto local reefs in an effort to rehabilitate areas where Elkhorn corals are in decline.
Many thanks to SECORE International for educating scientists, students and conservationists on site during the visit, and for its continued work to rehabilitate populations of essential, reef-building corals not only in Eleuthera, but throughout the Caribbean.
On August 20th, Dr. Craig Dahlgren from The Perry Institute for Marine Science Laboratory arrived at CEI along with more than 20 scientists and conservationists from around the Bahamas and United States to learn how to conduct reef surveys. The protocols focused on those developed for Atlantic and Gulf Rapid Reef Assessment (AGRRA). Formed in 1998, AGRRA assesses key attributes of coral reefs in the Caribbean using a standardized protocol leading to valuable regional surveys of coral reef health in an online database. AGRRA surveys incorporate coral, benthic and fish species. For this workshop participants were trained in either coral or benthic surveying, in order for each surveyor to be properly specialized, resulting in the highest quality data.
Data collected during AGRRA surveys is used to create Coral Reef Report Cards. Eleutheran reefs have never been surveyed using AGRRA protocols and therefore there has been a knowledge gap for this area. Some of the workshop participants were already AGRRA certified and conducted official surveys around South Eleuthera right away, while others began the training needed to conduct the surveys, led by Dr. Dahlgren.
The week-long training included diving and practicing survey methods out on the reefs as well as classroom time learning and identifying species of coral and algae. Members of CEI were also included in the training in order for AGRRA surveys to be carried out all around Eleuthera in the future to fill knowledge gaps and help advise marine resource management decision-making.
Participants involved in the surveying and training included members from The Bahamas National Trust, Bahamas Reef Environment Educational Foundation (BREEF), The Nature Conservancy, The Bahamas Environment, Science and Technology Commission, Disney Conservation Fund, , Stuart Cove’s Dive Bahamas, Perry Institute for Marine Science, Atlantis, Ocean Crest Alliance, , Greenforce, Forfar Field Station, and Young Marine Explorers. After a busy week everyone was an official AGRRA surveyor and many surveys had already been conducted on the nearby reefs!
Stay tuned to hear more about the workshop conducted by SECORE International involving these participants that combined with their AGRRA training during the week.
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.
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.
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.
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.
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.
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.
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.
Over the course of six weeks, Natasha Webbe of the University of Leeds, a student representing Operation Wallacea, has been working with the Cape Eleuthera Institute to study the success of the coral nursery set up in Cape Eleuthera. This will be determined by studying staghorn (Acropora cervicornis) and fused staghorn coral (Acropora prolifera) growth rates in relation to the environmental conditions surrounding the coral restoration nursery installed near CEI in March 2014 in collaboration with the University of Miami.
Coral reefs are extremely important worldwide as the most biologically diverse ecosystem, providing essential goods and services. The Bahamas, in particular, are dependant upon coral reefs to support their fishing industry through the habitats they provide. Acropora cervicornis is a major coral reef building species however have been classified as critically endangered by IUCN’s red list, therefore, conservation efforts are crucial to re-establishing healthy coral reefs around Eleuthera, The Bahamas, and the Wider Caribbean.
This project consists of measuring each coral fragment growing in the nursery and conducting data analysis on three years’ worth of data to assess growth rates at different depths of the tree and during different seasons of the year. Complexity will also be studied as fragments with higher complexity may be more beneficial for transplantation, aiding the outplanting success in the long term. Fragments are vulnerable to thermal stress due to climate change causing bleaching and the overgrowth of algae. Therefore, using an index, bleaching and algae have been recorded and can be compared with previous data to establish any significant correlations with the time of year or environmental conditions. Additional observations are recorded, such as, Domecia acanthophora crabs which are known as the ‘Elkhorn crab’ and are good for coral nurseries. Water samples have also been taken to analyse pH and salinity as well as having recorded temperature on site to see whether any of these variables are affecting growth rates.
This research will form the basis of Natasha’s undergraduate dissertation aiming to determine any relationships between A. cervicornis and A. prolifera growth rates and their environment in the nursery. This can establish their optimum growth conditions to further improve the coral nursery as a restoration method.
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.
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.
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.
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!