Bull Sharks, Fiji
Shark Reef Marine Reserve, Fiji
The main aim of the Bull Shark Tagging Programme is to better understand the behaviour and ecology of bull sharks.
Why this is important:
Bull sharks (Carcharhinus leucas) have a worldwide distribution in coastal and freshwater habitats with frequent sightings in some areas, yet many aspects of their behaviour and ecology remain a mystery. With a lack of knowledge about local population structures, reproduction sites and the migratory routes to and from these areas, it has been impossible to draw up any meaningful conservation plans.
The Bull Shark Tagging Programme was initiated in 2003 and has been co-funded by SOSF since 2004. The initial pilot study in the Bahamas tested the feasibility of studying movement patterns and habitat use of bull sharks with state-of-the-art pop-up satellite archival tags (PSAT). The pilot study revealed that bull sharks, residing in a relatively small area close to Walker’s Cay for most of the year, would leave the site in the spring and travel as far as the eastern coast of the US. This is the first indication of movement of bull sharks between the Bahamas and the Florida coast, underscoring the need for international co-operation in shark conservation.
Since 2004, the main field site of the Bull Shark Tagging Programme is located in the South Pacific. The scope of the project is now much broader and includes other shark and fish species inhabiting the Shark Reef Marine Reserve in Fiji. Here, up to eight different species of sharks can be encountered on a regular basis making it an excellent reef for studying free-ranging sharks and other reef fishes in their natural environment.
The main aim of the Bull Shark Tagging Programme is to better understand the behaviour and ecology of bull sharks. Besides this, the long term goal of the project is to establish the Shark Reef Marine Reserve as a prime site for shark research and to produce scientific data that will help towards the conservation of the various shark and fish species that regularly visit the marine reserve. In order to implement meaningful conservation measures, basic biological data such as population sizes and dynamics, habitat use, nursery and mating grounds, and small- and large-scale movement patterns must be known.
One particularly important aspect of the project in Fiji is the investigation of shark behaviour as a response to a tourist shark feeding dive. Feeding of elasmobranches has become a popular means by which tourists and tourism operators can facilitate close observation and interaction with sharks and rays in the wild. Feeding wild sharks is a controversial issue and has received a lot of public and media attention.
Aims and Objectives
The project uses the full spectrum of telemetry techniques, ranging from direct observation of sharks and fish in their natural habitat to acoustic and satellite telemetry, as well as genetics and local ecological knowledge.
The following projects are currently underway in Fiji:
- the Bull Shark Tagging Programme investigates large- and small-scale movements of bull sharks using satellite and acoustic telemetry as well as direct observation of the sharks in their natural environment. Whereas the large-scale movement studies are principally aimed at identifying and eventually protecting the bull shark nurseries in the rivers, the small-scale movement research is aimed at determining the optimum size and geographical extension of the protected area. We aim at testing several hypotheses linking the periodic disappearance of the bull sharks in spring/early summer to their birthing and mating cycles.
- exploring local and traditional ecological knowledge along all of Fiji’s major rivers. Local and traditional ecological knowledge have the potential to improve community-based coastal resource management by providing baseline data such as information about the presence, behaviour and ecology of species inhabiting these environments. Our major aim is to explore the potential of local and traditional ecological knowledge to identify shark river habitats in Fiji, to learn how locals regard and use sharks, and to capture ancestral legends and myths that shed light on the relationship between local people and these animals.
- Maintaining an exhaustive database about the shark dives. This is the backbone of the research into population dynamics, life cycles, inter- and intra-specific interactions and questions pertaining to the shark diving industry, namely the effects of the shark diving operators’ activities on the animals and the optimum procedures one ought to adopt in order to ensure a maximum of safety.
I’m very happy to share this with you: Opportunistic visitors: long-term behavioural response of bull sharks to food provisioning in Fiji. The image shows the female bull shark Rip at the feeding site in the Shark Reef Marine Reserve on…
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I recently came across an Editorial in Nature and a News Feature in the same issue that caught my attention. The authors call for a debate, initiated by scientists, about the risks, benefits and ethics in using research results from…