Background

The need for this project was identified during recent elasmobranch and ecosystem management meetings conducted by the International Council for Exploration of the Seas (ICES) and the International Convention for Conservation of Atlantic Tunas (ICCAT). These meeting revealed a paucity of data on porbeagle distribution, abundance and horizontal migration regimes in the Northeast Atlantic, and highlighted a pressing need for fisheries-independent data on this vulnerable species. The need for a fisheries-independent abundance index survey on porbeagles was particularly emphasised in order to assess the state of porbeagle stocks in the region so that effective management could be devised. However, it was noted that the species occupies a wide distributional range in the Northeast Atlantic and that the main centres of stock-distribution was unknown, making it difficult to establish robust sampling sites for such an abundance survey.

The Marine Institute, in collaboration with Centre for Environment, Fisheries and Aquaculture Science (CEFAS), French Institute for Exploitation of the Sea (IFREMER) and Association for the Conservation of Sharks (APECS), identified the utility of using satellite tracking methods to establish the main centres of porbeagle distribution within the Northeast Atlantic to address this problem and to gain new insight into the species habitat preferences that might bee useful for establishing Marine Protected Areas. Furthermore, the porbeagle is arguably one of most understudied, iconic marine predator that resides in the Northeast Atlantic. Ireland has important concentrations of porbeagles where they are often found frequently around the northwest coast during the summer months. The region also has a strong recreational angling community for gamefish, such as pelagic sharks, providing a unique opportunity to study porbeagles using satellite tags and involve local anglers/fishermen in concrete conservation action. Furthermore, the MI has strong links with the Irish Elasmobranch Group, providing an excellent media outlet for raising conservation awareness for the species and enhancing the profile of our research.

Aims and Objectives

Our project will gain new data on porbeagle horizontal movement patterns, habitat preference and diving behaviour that will lead to effective, long-term conservation measures for the species throughout its distributional range. Our project also aims to raise invaluable conservation awareness for the species by communicating results to a wide range of target audiences, such as the general public, policy managers and the fishing industry.

The general aim of the project is to deploy satellite tags on porbeagle sharks around Ireland. Data from these platforms will enable us to:

1. Gain new insight into porbeagle migration, diving behaviour and habitat preference of porbeagles in the Northeast Atlantic.
2. Determine the parturition and nursery grounds of porbeagles by tagging mature females.
3. Understand the movement pattern of the species in relation to commercial fisheries to assess the possible impact of porbeagle-fishery interactions.
4. Underpin the population boundaries of the species to ensure robust assessment and management.
5. Raise conservation awareness for porbeagles through regular, high-impact media communication.