Sharks on the Move: species distribution modelling of migratory sharks to inform ecosystem-based management under global change

Sharks play a key role as predators in the structure and functioning of marine communities. Three of the largest species in Norway, the basking shark, porbeagle and spurdog are considered endangered. However, some of the most fundamental and critical information about their distribution and the drivers of their occurrence are lacking. We also do not know in how far their distribution overlaps with areas of intense human activities and in how far the sharks are potentially affected and especially vulnerable in these areas. Increased knowledge of the sharks’ potential habitats in an ecosystem under pressure from fisheries, coastal development and climate change is therefore critical to assessing their vulnerability to these factors. The project’s objective is to strengthen our understanding of the environmental and ecological drivers of the present and projected distributions of these three shark species in Norwegian waters, using amongst others tagging experiments and data modelling. We will investigate the effects of human activities by combining information on fishing and aquaculture activities with observed and modelled shark distributions. The project aims to inform researchers and managers about factors that directly and indirectly affect the distribution of these sharks now and in the future, with a special focus on critical habitats, migration routes, climate change and interactions with fisheries and aquaculture. Identifying hotspots for potential conflicts is crucial for the sustainable management of these vulnerable sharks and their ecosystems, both today and in the light of projected climatic change.

Sharks play a key role as predators in the structure and functioning of marine communities. Three of the largest species in Norway, the basking shark, porbeagle and spurdog are considered endangered. However, some of the most fundamental and critical information about their spatio-temporal distributions, drivers of occurrence, and overlap with and vulnerability to human activities is lacking. Meanwhile, their ecosystems are under intense pressure from fisheries, coastal development and climate change, which in turn are likely to impact these shark species. The project’s objective is to strengthen our understanding of the environmental and ecological drivers of the present and projected distributions of these three species in Norwegian waters. We approach this, using a combination of existing data analysis, new tagging experiments and multi-trophic, data-driven, and comparative modelling. We will investigate the effects of human activities by combining information on fishing and aquaculture activities with observed and modelled shark distributions. In combination, tracking and modelling will provide novel insight and forecast on shark space use, informing researchers and managers about critical habitats, migration pathways, effects of climate change, and interactions with fishing gears and fish farms. Identifying hotspots for conflicts is crucial for the sustainable management of these vulnerable sharks and their ecosystems, both today and in the light of projected climatic change. Through partnering with the Directorate of Fisheries and Runde Environmental Centre AS, project goals have been a priori discussed driving the project’s research direction and communication strategy, ensuring relevance of the project’s outputs and efficient communication of new knowledge from 'Sharks on the Move' about these sharks and their ecosystems through targeted communication activities to the public, industry and other stakeholders.