On Wednesday, 3rd February, the Shark Research and Conservation Team captured and sampled only the fourth ever Great Hammerhead shark (Sphyrna mokarran) caught off of Eleuthera in the entirety of the program’s ten-year operation. During a shark ecology and handling class for the Cape Eleuthera Institute’s Gap Year Program, led by Research Assistant Oliver Shipley and Educational Assistant Cameron Raguse, the students were able partake in a rare experience in handling one of the most data-deficient sharks found in The Bahamas. Increasing our understanding of sharks in The Bahamas is important to ensure the most applicable and effective management of these keystone apex predators.
Hammerhead sharks (Sphyrnidae) are a morphologically distinct family of elasmobranchs comprising of nine species, and are found in temperate and tropical waters around the globe. They have evolved a unique dorso-ventrally compressed and laterally expanded cephalofoil that allows them to expand their field of sight and pin down prey items such as stingrays. Their common diet consists of molluscs, annelids, crustaceans, teleosts, and even other elasmobranchs. Great Hammerhead’s (Sphyrna mokarran) reach up to 3.5 m and weigh up to 230 kg. They are a highly migratory and solitary species that lives in coastal-pelagic waters near continental shelves. They are known to migrate from tropical to more temperate waters during the summer months to seek cooler water, and have been observed using offshore habitats including deep-water.
In The Bahamas, the biological and economic importance of sharks has been well recognized, leading to the 2011 amendment to the Fisheries Resources (Jurisdiction and Conservation) Act (Chapter 244), establishing The Bahamas as a National Shark Sanctuary. This declaration has provided thorough protection for a plethora of shark species, through the banning of commercial fishing and transport of shark related products into or outside of the approximately 630,000km2 that encompass The Bahamas.
This Great Hammerhead was captured during one of the shark team’s routine experimental longline surveys. The goal of this work is to gather tissue samples, such as muscle, fin and blood from a wide range of coastal elasmobranchs, to determine their diet, and subsequently the scale to which they perform important ecological controls. The experimental longline consists of a 500m mainline equipped with 40 gangions which terminate in baited hooks and are supported by flotation buoys. Lines are soaked for a total of 90 minutes before being retrieved.
In addition to collecting tissue samples, the team also took measurements, a DNA sample, and attached two identification tags. This work-up procedure was completed in less than five minutes before the animal was safely released. A video of the release can be found on our Instagram page (@ceibahamas).
A spawning aggregation of thousands of bonefish (Albula vulpes) was recently filmed in South Eleuthera. Bonefish make monthly migrations of up to 80 km (50 miles) to form spawning aggregations!
CEI’s Flats Ecology and Conservation Program is currently studying the spawning migrations of bonefish, which support a catch-and-release flyfishing industry worth over $141 million annually in The Bahamas. To view our most recent publications on this economically important species, please visit our website www.ceibahamas.org.
The Spring 2016 Team Gap has had a great first few weeks. Everyone has gotten to know each other very quickly and we are all enjoying our time in Eleuthera.
We began the week with some snorkeling introductions and began our marine ecology class, learning the fish of The Bahamas, and putting that into context learning about coral reef ecology.
We wrapped up the week with a South Eleuthera road trip to learn about and see different parts of the island. Team Gap is looking forward to the next 8 weeks of learning and laughs. Stay tuned for more updates on our adventures.
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.
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.
Previous research indicates that bonefish migrate up to 80 km from shallow flats and tidal creeks to deeper water to spawn during the full and new moons. At these locations, bonefish gather in schools of hundreds to thousands of fish, forming spawning aggregations. To date, migration corridors and spawning aggregations have been located in South Eleuthera, Abaco, Andros, and Grand Bahama, and this information was used to create national parks on Abaco and Grand Bahama. The purpose of this telemetry study is to identify bonefish spawning aggregations and migration corridors around the island of Eleuthera. Information generated by this research can be used by the Department of Marine Resources and BNT to designate marine parks on Eleuthera, which will help The Bahamas meet the goal of protecting 20% of their marine environments by 2020.
Last Friday, Deep Creek Middle School’s Grade 7 joined Georgie Burruss, CEI Research Assistant, for a snorkel through Page Creek as part of the School Without Walls program. The focus of Grade 7′s School Without Walls program this year is human impacts on the environment. Nearshore environments, especially mangrove creeks, serve as a great educational tool for displaying how even small-scale coastal development can be detrimental to coastal habitat.
The students drifted with the incoming tide into the creek, practicing fish ID that they learned that morning with Liz Slingsby, Director of Summer Term and Gap Year Programs. At the end of their first snorkel through the creek, the students were able to successfully ID over a dozen fish species and discussed how mangroves act as nursery grounds for ecologically and economically important species such as snapper and lemon sharks.
With the excitement of snorkeling and floating with the current, the students quickly rushed to float down again. At the end, the group met and discussed how humans might affect mangrove creek systems. The students quickly recognized pollution and habitat degradation as some of the major impacts that humans can have on these important systems. As the group walked out of Page Creek, they observed how even a short beach access road can divide a creek, limiting available habitat.
CEI researchers look forward to spending more time with DCMS students during the School Without Walls programs!
Have you ever come across an animal – whether fish, bird, mammal, or even coral – that was impacted by plastic? Share your observation and details with the “Plastic Pollution: Impacts on Wildlife” project at http://www.anecdata.org/projects/view/123, a new citizen scientist page started by CEI researchers.
Photo info: From entanglement to asphyxiation, marine debris can have severe effects on animal health. Even small pieces of plastic, such as these collected from a great shearwater (Puffinus gravis) found washed ashore, adsorb pollutants from the environment, thus acting as a vector for the bioaccumulation of pollutants in birds, fish, and marine mammals.
Last week, researchers from The Cape Eleuthera Institute traveled to Abaco for the 7th Biennial Abaco Science Alliance Conference (ASAC) hosted by Friends of the Environment. Over the course of two days, posters and presentations alike highlighted research findings in natural history and environmental science in The Bahamas. Drawing a diverse audience with scientists from The Bahamas to as far as Canada, local community members and high school students from Abaco, the conference provided a forum for sharing scientific knowledge on the diverse ecosystems of The Bahamas.
Dr. Owen O’Shea, Research Associate for the Shark Research and Conservation Program, gave an engaging presentation on the ongoing stingray research project at CEI and ecosystem-driven approaches to conservation. Candice Brittain, Applied Scientific Research Department Head, spoke about the recent assessment of the queen conch nursery ground in South Eleuthera. Her presentation was followed by a workshop on conservation of queen conch in The Bahamas, led by the Bahamas National Trust. Georgie Burruss, Research Assistant for the Flats Ecology and Conservation Program, presented new findings on marine debris in the Exuma Sound and plastic ingestion by pelagic sportfish. She also gave a talk on studies conducted by the Flats Program that have aided in developing the Best Handling Practices for bonefish and protection of critical bonefish habitat. Finally, Eric Schneider, graduate student at University of Illinois Urbana-Champaign, presented research he conducted at CEI on temperature change effects on juvenile and adult schoolmaster snapper.
ASAC provided a unique opportunity for networking between the local community, students, and researchers for sharing knowledge on ecosystems across The Bahamas. Researchers from CEI look forward to attending ASAC in 2018!
The invasion of lionfish on reefs of the West Atlantic has become an issue of critical concern. With eradication not possible, the silver lining is that lionfish are delicious. The You Slay, We Pay campaign was launched by Dr. Jocelyn Curtis-Quick to support the development of a local lionfish market in The Bahamas. The Island School bought lionfish from local Bahamian fishers to consume in the dinning hall.
The slayer campaign initially ran through lobster closed season in 2014, as this is the time of year that many fishers will switch to conch harvesting, which is less lucrative as a fishery and increases pressure on the already overfished species. This trial lionfish season was so successful that in December of 2014 (during the closed grouper season) the lionfish You Slay, We Pay was launched all year round. Over 1500 lbs of lionfish were brought in throughout 2015, with new fishers joining regularly and more lionfish meals being enjoyed on campus. We hope that 2016 sees even more lionfish removed from the reefs and on the plate.
Over two semesters Dr Jocelyn Curtis-Quick and Alexio Brown led an Island School Research class focused on exploring and assessing the inland ponds of Eleuthera. These inland ponds are fragile and are under threat from human disturbance, but are rarely visited and poorly studied. The students assessed 16 sites across Eleuthera; 69% of the ponds were impacted by humans. In the few non-impacted sites, species that are new to Eleuthera were found.
Just last week, expert Professor Mary Wicksten of Texas A&M University confirmed Eleuthera is home to not one but two species of critically endangered cave shrimp, Parhippolyte sterreri and Barbouriacubensis.This further highlights the need for immediate conservation of the anchialine systems in order to protect this unique habitat and the life it supports. The ponds project is a new and exciting area of research for CEI. Dr Jocelyn Curtis-Quick presented the research at the 3rd International Symposium on Anchialine Ecosystems in 2015, and two of The Island School Bahamian students will present at the Abaco Science Alliance and the Bahamas National Natural History Conference in 2016. We hope to create awareness for this unique ecosystem and ensure its protection.