Improvement Knowledge of Sandbar Shark (Carcharhinus plumbeus) in Boncuk Cove, Gökova SEPA, Turkey

Bengi Atay

Sharks are one of the apex predators of the Mediterranean Sea. They are the most powerful and charismatic species of the seas. But over 75% shark species are currently threatened with extinction. Sharks reproductivity is extremely slow; also bycatch and overfishing are causing severe declines in the populations that are already shown to monitor. This study will focus on sandbar shark (C. Plumbeus) in Boncuk Bay. Sandbar sharks are currently endangered (EN) in IUCN Red List. Boncuk Bay is known as one of the most famous and important nursery grounds for sandbar sharks in the Mediterranean. Boncuk Bay is also a No Fishing Zone (NFZ) as a part of the Gökova Special Environmental Protection Areas (SEPA). In this respect, this area provided that the species can safely distribute in this zone. This study’s main goal is to observe the sandbar sharks’ behaviours and collect new data on species behaviour through the use of acoustic telemetry technology.

A few observations from the monitoring studies conducted by AKD. © AKD.

A few observations from the monitoring studies conducted by AKD. © AKD.

Acoustic and radio telemetry have been used in marine science for more than 50 years and have revealed new information on the movements and behaviours of important aquatic species. Acoustic telemetry is a widely used aquatic tracking method, in which the signals transmitted from implanted or externally attached acoustic transmitters are detected and logged by nearby acoustic receivers. It consists of two main components: transmitters and receivers. In this project, we will be using the Vemco VR2W (69 kHz) model acoustic receivers and Vemco V16-4 H model acoustic transmitters. These transmitters will record the depth and water temperature of the tagged fish along with the temperature and depth sensors it is configured for. Acoustic receivers will be checked every 6 months to retrieve data and will be analysed.

The project will also be focusing on raising public awareness in the area, especially among the small-scale fishing community that are organised through three fishing cooperatives. A survey will be conducted with fishers to measure awareness around the species and bycatch safe handling and release. According to the results of the survey, a workshop will be held with fishers to improve their knowledge on bycatch safe handling and release.

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