Seascape Approach To Improving Fisheries Sustainability

Numerous fish stocks in economically developed nations are harvested sustainably or are in recovery. Yet, despite more than a decade of rebuilding attempts West of Scotland finfish fisheries remain in crisis. The destructive effects of mobile fishing gear on benthic habitats and the loss of high-quality habitat networks are likely factors contributing to the lack of recovery of these fish stocks. This is a complex and contested issue; resolution is needed to reverse biodiversity decline and support thriving coastal rural communities.

Biodiversity restoration and sustainable use of natural capital like fisheries require knowledge of the distribution and movements of exploited species across a landscape. This studentship will develop state-of-the-art understanding of fish-habitat relationships at patch and seascape scales, provide a model for incorporating habitat and landscape considerations into fisheries management and influence Scottish Government policy.

Habitat use and occupancy is often inferred by considering the immediate habitat where fish are found. However, we also recognise that different habitats confer different benefits such as refuges from predation or feeding areas. Therefore, it is essential to not only consider the immediate habitat occupied by an animal but also the wider environment and variety of habitats available. This PhD will adopt a novel seascape approach which understands that the spatial arrangement of marine habitats is important, and that links must be maintained to allow animals to move between them.

While previous work has shown the local abundance of juvenile gadoids to increase with increasing habitat heterogeneity, we do not know how patch size, or the arrangement of patches influences abundances. Additionally, at broad spatial scales of
Modelling the distributions of many species is possible because behavioural traits which influence their densities are often minimal. However, some species maintain constant densities and are vulnerable because they display hyperstability (e.g. spawning cod or grouper). The work of this project will also develop seascape models which include species that maintain constant densities in a habitat patch and, by using wrasse as model species, explain the role played by behaviours which govern densities across seascapes.

This project will develop understanding of fish ecology and conservation, providing urgently needed information about fish habitat relationships, develop methods and a research strategy for seascape-based conservation and management to reverse biodiversity decline.