Cayman Shark Study
The project will investigate a) movements of reef shark species around the Cayman Islands, b) the effects of attracting reef sharks for shark-watching tourism, c) the feasibility of tracking larger potentially dangerous sharks to provide a real-time alert system at sensitive tourist areas, and d) the occurrence of specified cetacean species in offshore sea areas.
Why this is important:
The study will greatly assist the Cayman Islands protect these key components of their marine biodiversity and support sustainable, economically beneficial use of these iconic species.
A research team is assisting the Department of Environment (DoE) with surveys around all three islands and will also build on the DOE efforts to establish a public sightings scheme for recording observations of sharks, whales and dolphins seen in Caymanian waters.
The team will be collaborating with marine scientists from the Department of the Environment whose Deputy Director Mr Tim Austin said: “We’re really excited to be working with this group of experts on these important issues. Sharks, as top-level predators in our marine environment are key components and we have very little reliable data or information on local species, populations and the pressures they face. Additionally through this project we hope to expand on local efforts to better understand what species of whales and dolphins use Caymans’ waters as part of their home ranges or seasonal migratory routes, as currently very little is known.”
The project is being jointly funded by the UKs Overseas Territory Environment Programme (OTEP), the Save Our Seas Foundation and the Caymans Department of the Environment. The project leader Dr. Mauvis Gore, who obtained her PhD from the University of the West Indies, said: “I am thrilled to be in Cayman again. The coral reefs here are impressive, but I’m excited that this time we to have the chance to focus on the area’s sharks. Well over 90% of the worlds shark populations have been lost over the past twenty years, largely through illegal fishing simply for making soup in distant restaurants. Here the marine environment is better managed and so there is a chance to ensure that endangered species are not lost.”
Dr. Rupert Ormond, a past director of the University of London’s Marine Biological Station in Millport, Scotland, said: “The Save Our Seas Foundation is delighted to be associated with this project, the foundation’s work in recent years has focused on highlighting the plight of sharks. In particular our Rethink The Shark campaign has emphasised the fact that shark attacks are extremely rare, often the result of provocation, and that many more people are killed by toasters and chairs each year, let alone by bees or cars. In addition the research that we have funded worldwide has shown that the large charismatic sharks play a crucial role in maintaining the balance of the marine ecosystem.”
The project will emphasise collaboration with local fishermen, dive operators and boat owners who will be invited to share their knowledge and report sightings of sharks, whales and dolphins to the Department of the Environment.
Aims and Objectives
- Sonic Tagging of Medium-sized Sharks. A target of 50 individual sharks of common medium-sized species will be tagged with sonic (as well as conventional numbered) tags during standardised long-line sampling at sites around the three Cayman Islands, and during intensive fishing periods around the south-east and in the North Sound of Grand Cayman. Movement of tagged sharks will be monitored by recording their presence (location, date and time) through a) the acoustic receivers deployed at key locations and b) reports to the observer network of marker tags sighted during fishing or diving.
- Sonic & Satellite Tagging of Large Sharks. A target of 10 individual sharks of the less common large species will be tagged with both sonic and satellite tags (as well as conventional numbered tags) during intensive tagging campaigns around the north-west quarter of the island. Movement of these sharks will be monitored both a) sonic receivers deployed at key locations, including near by to tourist site, and b) data returns via satellite from satellite tags which will reveal the broadscale movement of these animals.
- Use of BRUVs to Study Effects of Provisioning Baited Remote Underwater Video Systems (BRUVs) will be set at intervals at locations around the three islands as part of the ongoing work. In addition, under the new project, BRUVs will be set more frequently at a series of stations around the south-east of the island. The BRUVs will detect any increase in numbers or activity of sharks as a result of artificial provisioning at the experimental site.
- Acoustic Receiver Network and Alert System There is an existing acoustic receiver network around each of the three islands, used to monitor the movements of groupers; however additional receivers will need to be acquired and set at a series of additional locations, notably in the north-west of Grand Cayman near the tourist sites, and around the south-east of Grand Cayman, where the experimental provisioning will be undertaken. These moored receivers need to be recovered (by divers) at intervals of 2-3 months in order to download the data, consisting of the times and identities of all tag detections. In addition however trials will be undertaken involving the deployment of mobile receivers (providing real-time detections) by DoE staff present in boats overseeing visitors to sensitive tourist sites.
- Test of Alert System In addition to the moored receivers, trials will be undertaken involving the deployment of mobile receivers (providing real-time detections) by DoE staff present in boats overseeing visitors to sensitive tourist sites.
- Offshore Aerial Surveys Surveys by boat for cetaceans are being conducted, as part of the present on-going project, both nearshore (< 5 km) around all three islands, and offshore on passage between the islands. These surveys involve the use of “distance line-sampling” methodology and the regular deployment of hydrophones to detect any cetacean calls or sound, and will be extended further offshore where time and vessels of opportunity allow. Subject to separate funding, under the new project, aerial surveys will be undertaken to provide more regular extensive coverage of target areas further offshore.
- Observer Network & Public Sightings Scheme The Observer Network and Public Sightings Schemes, established under the existing project, will be supported for a further year under the new project, with a view to gaining sightings of tagged sharks and additional cetacean species. SCUBA divers visiting resorts in the south-east sector of the island will also be instructed in shark biology and involved in a more formal effort-based reporting scheme.
- Environmental-Economic Assessment This work will be undertaken by graduate researchers from the University of York (one person making one 4-month visit per year). It will comprise both desk studies of comparable locations elsewhere, economic assessment of SCUBA diving industry in the Caymans, and interviewing and contingency evaluation of the potential add-on benefit of shark-watching activities.
- Data Analysis and Reporting A portion of the time will need to be set aside for data-analysis and report writing. Since accommodation and living costs are lower there, much of this work will be undertaken in the UK. Results of the project will be disseminated via one or more formal reports to the DoE, 3 proposed scientific papers, a project web-site and linked Facebook page, popular articles, approximately quarterly press releases and appearances on TV.
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