ÌÇÐÄÊÓƵ

New research from the University of St Andrews provides important insights into patterns of marine mammal bycatch in UK fisheries.

Published this week in the , researchers analyzed a long-term dataset (1996–2023) collected under the UK Bycatch Monitoring Program (BMP), to explore patterns in bycatch rates and identify factors associated with marine mammal bycatch in UK static net fisheries.

Bycatch is the accidental capture of unwanted fish or other marine creatures in commercial fishing activity and can impact on a species population status or create practical and economic problems for fishermen.

The results indicate that there are seasonal patterns in bycatch rates for harbor porpoise, common dolphin and seals. Longer term changes in bycatch rates over the time period were also detected. These findings can help refine bycatch estimation procedures which form part of sustainability assessments and also inform the development and introduction of targeted measures to mitigate bycatch. Targeted measures will help ensure bycatch levels do not pose a threat to the long-term viability of affected populations, while simultaneously minimizing impacts on the fishing industry.

Co-author, Dr. Faye Moyes from the University of St Andrews School of Biology, said, "This research was prompted by discussions with staff at the University, including the late Professor Simon Northridge, and provides the most comprehensive analysis to date of marine mammal bycatch in UK waters. The results highlight the importance of long-term monitoring programs to help support evidenced based fisheries management and biodiversity conservation in the UK and beyond."

Another finding from the work suggests that current efforts to reduce small cetacean bycatch using a particular model of acoustic deterrent device (ADD or "pinger") in some fisheries, is reducing harbor porpoise bycatch rates significantly but may be increasing seal bycatch.

Co-author and BMP coordinator Al Kingston, senior research fellow from the School of Biology, said, "This unwelcome finding with regard to seal bycatch highlights the complexity of bycatch management and mitigation, but will now help steer further research and development efforts to ensure that measures designed to reduce the bycatch of one species do not simply create another problem, while also remaining practical and cost-effective for industry to implement."

The BMP, one of the largest and most comprehensive bycatch data collection programs in the North Atlantic, was launched in 1996. Today the program is run by the University of St Andrews in partnership with other academic and government marine scientists, and national fishing industry organizations.

Al Kingston added, "the longevity and ongoing expansion of the BMP is testament to Professor Northridge's philosophy of working collaboratively with the fishing industry to continually improve understanding of the wider impacts of fishing activity on the marine environment to support the development of truly sustainable, productive, profitable and safe fisheries that will help ensure future food security for the UK."