Management of scallop fisheries to reduce the environmental impact on seabed habitats

Abstract

The king scallop (Pecten maximus) fishery in the UK is a significant economic resource, contributing over £50 million annually in first sales. However, the primary harvesting method—scallop dredging—raises major environmental concerns due to its impact on seabed habitats. Current management strategies primarily focus on conserving target species, neglecting broader ecosystem protection. This thesis critically reviews global and UK-specific scallop fisheries management practices, revealing the inadequacies of existing measures in addressing environmental damage. By utilising vessel monitoring system (VMS) data, the spatial distribution and intensity of scallop dredging in the UK Exclusive Economic Zone (EEZ) are mapped, highlighting the most affected habitats. A risk assessment framework is developed to identify and prioritise the management of Vulnerable Marine Ecosystems (VMEs) at greatest risk from dredging, highlighting gaps in Marine Protected Area (MPA) management. The thesis also examines the concept of 'marginal' fishing grounds—areas that offer significant conservation benefits while carrying low economic value—suggesting that their protection could minimise ecological harm with minimal economic impact. In addition to spatial and effort-based management, a gear modification aimed at reducing seabed impact was assessed. The addition of skids onto scallop dredges to reduce seabed contact showed promise, though increased bycatch and undersized scallops indicate further refinement is needed. The research emphasises the need for continuous innovation in fishing gear design as part of a comprehensive management strategy. The thesis concludes with recommendations for a holistic, integrated approach to UK scallop fishery management. Combining spatial, effort-based, and technical interventions, this approach offers a sustainable path forward that balances environmental conservation with the economic viability of the fishery for future generations.