Category Archives: Visiting Scientists

CEI and SECORE document critically endangered coral spawning

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.

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~50,000 Elkhorn coral eggs in a coral breeding system collected from Halfsound, Eleuthera by SECORE International.

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.

Various brooding corals collected to obtain coral larvae. The species are Undaria humilis and U. agaricites.
Various brooding corals collected to obtain coral larvae. The species are Undaria humilis and U. agaricites.

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.

Coral reproduction workshop led by Dr. Dirk Peterson from SECORE International. Here, various scientists and conservationists are collecting brooding coral larvae from individual tanks to be observed under the microscope!
Coral reproduction workshop led by Dr. Dirk Peterson from SECORE International. Here, various scientists and conservationists are collecting brooding coral larvae from individual tanks to be observed under the microscope!

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.

Coral reef survey techniques workshop help at CEI

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.

Surveys were conducted at the few Eleutheran reefs left with Staghorn coral, an endangered species in the Caribbean (Photo C. Dahlgren).
Surveys were conducted at the few Eleutheran reefs left with Staghorn coral, an endangered species in the Caribbean (Photo C. Dahlgren).

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.

Elhorn coral colony (Photo C. Dahlgren)
Elhorn coral colony (Photo C. 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.

A coral survey is conducted, identifying, measuring, and assessing health of species found along the reef (Photo C. Dahlgren).
A coral survey is conducted, identifying, measuring, and assessing health of species found along the reef (Photo C. Dahlgren).

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!

Participants from organizations all over the Bahamas joined us.
Participants from organizations all over the Bahamas joined us.

Stay tuned to hear more about the workshop conducted by SECORE International involving these participants that combined with their AGRRA training during the week.

 

Operation Wallacea student investigates growth rates at the CEI coral nursery

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.

University of Leeds undergraduate student Natasha Webbe by the coral nursery at Tunnel Rock
University of Leeds undergraduate student Natasha Webbe by the coral nursery at Tunnel Rock

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.

Healthy coral fragment (A. cervicornis) on the coral nursery
Healthy coral fragment (A. cervicornis) on the coral nursery

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.

Domecia acanthophora on one of the coral fragments on the nursery
Domecia acanthophora on one of the coral fragments on the nursery

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.

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!

 

Summer research focusing on critically endangered coral reef species

Elkhorn (Acropora palmata) and staghorn (Acropora cervicornis) corals are major reef-building corals found off the shores of Florida and throughout the Caribbean. In recent decades there has been a widespread decline in distribution and abundance of elkhorn and staghorn corals. Their decline is the product of compounding effects from local stressors and global factors linked to climate change including ocean acidification, sea level rise, coral bleaching, disease, and the increased severity of hurricanes. The loss of the Acropora species negatively affects the reef function and structure. This summer, McMaster University student, Heather Summers, in collaboration with Operation Wallacea and the Cape Eleuthera Institute, has been investigating the abundance and distribution of the Acroporid coral populations in South Eleuthera, Bahamas.

Undergraduate dissertation student, Heather Summers, recording the habitat assessment score at one point along the transect.
Undergraduate dissertation student, Heather Summers, recording the habitat assessment score at one point along the transect.

The purpose of this study is to collect qualitative and quantitative observations of coral reefs for use in the development of a mathematical model that will help describe these complex marine ecosystems. The data collected includes benthic assessment, species abundance, bleaching status, and environmental conditions of temperature, pH, and salinity. At each site transects are laid out and benthic communities are assessed using habitat assessment scores (HAS) and the line-point-intercept method in order to quantify the coverage of live scleractinian coral and macroalgae. This research project also investigates the impact of predation and herbivory on coral health by recording the abundance of key fish families and invertebrates including Diadema antillarum, Scaridae, Acanthuridae, Pomacentridae, and Pterois. The information amassed by this research project can help inform decisions on coral nursery site selection and identify potential donor colonies for regeneration in the nursery.

Staghorn coral colony
Staghorn coral colony

Coral reefs are complex, dynamic marine biomes and their health is reliant upon many factors. This complexity makes coral reefs ideal platforms for the development, testing, and validation of mathematical models that can be used to help explain and predict the impacts of adverse conditions on Acropora health.

Elkhorn coral colony
Elkhorn coral colony

If you spot any elkhorn or staghorn on Eleuthera or elsewhere throughout the Bahamas please report it to us! info@ceibahamas.org

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

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!

Graduate student Dan Montgomery working on stingray research at CEI

The team take measurements of a stingray prior to fitting an iButton
The team take measurements of a stingray prior to fitting an iButton

In the past week, members of the Stingray Research Team from the Shark Research and Conservation Program (SRCP) have begun work on a new project investigating the thermal ecology of southern stingrays (Dasyatis americana). As part of the research for this new study, the stingray team, assisted by gap year students and interns, fitted southern stingrays with temperature recorders. These recorders monitor seawater temperatures experienced by stingrays every 15 minutes for 3 weeks.

Southern stingray fitted with iButton swims away after release
Southern stingray fitted with iButton swims away after release

All sharks and rays are ectotherms, meaning their internal body temperature is controlled by the temperature of the environment around them. As such, changes in seawater temperature can impact the physiological processes of the animals, which may mean that temperature differences among the coastal waters of Eleuthera influence the areas which rays use.

Surgical needles are used to make holes in the stingrays tail in order to attach the iButton
Surgical needles are used to make holes in the stingrays tail in order to attach the iButton

Over the next 4 months, the study aims to tag 50 rays at both Marker Bar and the Schooner Cays, as well as conduct laboratory experiments with rays to identify thermal preferences. Also, temperature tags fitted to wild individuals will aid in understanding whether temperature is a driver of habitat selection in this ray species. Quantifying the drivers for habitat use of these ecologically important species is vital to effectively manage coastal marine habitats. The research is led by Daniel Montgomery, a postgraduate research student at Newcastle University, who is working in collaboration with Dr. Owen O’Shea and CEI.

 

Nassau grouper spawning aggregation expedition

Nassau grouper is an economically important species in The Bahamas. Due to heavy fishing pressure, there have been marked decreases in their population sizes, especially noticeable during their spawning season. The spawning season takes place during the winter months, from December to the end of February, and the aggregations occur during the full moon. Dr. Kristine Stump from the Shedd Aquarium has been monitoring Nassau grouper in The Bahamas to track their movements to spawning aggregations, as well as to quantify the number of Nassau grouper at these historical spawning sites.

The researchers that took part in the Nassau grouper work in front of the Shedd Aquarium vessel
The researchers that took part in the Nassau grouper work in front of the Shedd Aquarium vessel

This January, the Shedd Aquarium research vessel, The Coral Reef II, travelled to Long Island, to historical spawning sites, with a representative of The Cape Eleuthera Institute on board, to assist Dr. Stump with her research. Throughout the week-long journey, the researchers on board performed dive surveys to quantify spawning stock size at one specific site.  Unfortunately, very few Nassau grouper were aggregating at the site during the times of the surveys; at most 20 were noted on one survey. Illegal fishing was occurring at the time the vessel reached the site, which could explain the decreased abundance of the grouper. Poor weather conditions prevented the researchers from performing surveys on the night of the full moon, so it is unclear if numbers increased during the spawning event.  Continue reading

Global Finprint Project: Nassau Expedition

A juvenile tiger shark  (Galeocerdo cuvier) - one of three captured on camera
A juvenile tiger shark (Galeocerdo cuvier) – one of three captured on camera

Last week, four members of the Shark Research and Conservation Program (SRCP) travelled to Nassau, New Providence to participate in a global effort to assess the abundance and diversity of apex predators on coral reefs, termed The Global Finprint Project (GFP). The GFP is a Paul G. Allen initiative, facilitating global cooperation between various scientific institutions. The main goal is to collect abundance and diversity data on reef-associated elasmobranchs in order to provide a valuable baseline pertaining to their current population trends.  The call to assess the health of these populations is critical, as many are either listed by the IUCN as data deficient, or are showing rapid declines.  The GFP is the largest study of its kind ever undertaken, and the SRCP is responsible for surveying a multitude of sites across the greater Caribbean.

Abundance and diversity data is collected through a scientifically accepted, non-invasive methodology, Baited Remote Underwater Video (BRUVs).  BRUV’s consist of a camera, weighted frame, and bait arm, which provides a concentrated plume, designed to attract predators. BRUVS are deployed for 90-minute ‘soak’ periods in order to allow enough time for the plume to travel and disperse within the water column.  Over seven days the team collected over 100 hours of video from two regions (south west, and north east) off Nassau, New Providence, from depths ranging from 2m to 30m.

 

Two Caribbean reef sharks (Carcharhinus perezi) feeding from a bait crate
Two Caribbean reef sharks (Carcharhinus perezi) feeding from a bait crate

Preliminary assessment of the video data suggest a diverse array of sharks and other predators associated with reefs around Nassau. The team identified hammerhead, Caribbean reef, blacknose, nurse, and tiger sharks, as well as southern stingrays, amberjack, turtles and a Spanish mackerel.  Failing to robustly assess the diversity and the relative abundance of these animals has large implications for their effective management, and data collected from Nassau provides an intrinsic step to facilitating the success of this global conservation effort. Finally, our team would like to extend large thanks to Stuart Cove’s for their generous hospitality during this trip.

 

A southern stingray (Dasyatis americana) passing a BRUV unit
A southern stingray (Dasyatis americana) passing a BRUV unit