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Understanding fish mortality factors in Maximum Sustainable Yield calculations

We have been appointed to help Natural Resources Wales (NRW) better understand how natural and anthropogenic fish mortality estimates are incorporated in marine fish stock assessments. 


Leading marine consultancy, ABPmer, has been appointed to provide Natural Resources Wales (NRW) with an understanding of how natural and anthropogenic fish mortality estimates are incorporated in marine fish stock assessments. This will help NRW extend their knowledge of the potential impacts of developments on mobile fish species so that they can give appropriate advice to regulators and developers.

Under the Common Fisheries Policy the EU manages fish stocks to achieve their Maximum Sustainable Yield (MSY). MSY is a broad conceptual objective, aimed at achieving the highest yield over the long term by keeping fish stocks at a level producing maximum growth.

Annually, the International Council for the Exploration of the Sea (ICES) produces fish stock assessments for a number of marine fish species. These projections are used in determining appropriate fish stock management measures such as advice on sustainable catch levels in line with management plans.

Suzannah Walmsley, Fisheries Business Manager at ABPmer said:

“The mortality of fish stock is an important variable in MSY calculations. Our study reviews the fish stock assessment process and the components that are taken into consideration in the estimate of natural mortality, specifically for cod, whiting, herring, sprat, sandeel and mackerel in the Irish Sea and North Sea.
"Natural mortality includes all sources of mortality apart from fishing, and therefore includes mortality from predator-prey interactions, as well as anthropogenic sources of mortality. The estimation of natural mortality has progressed from a general assumption of constant mortality to age-specific estimates that take into account predation.”

ABPmer has expertise in fisheries policy and management, socio-economic impact assessment, planning and licensing for aquaculture, and seafood trade and value-chain analysis. They undertake fisheries and aquaculture research, data analysis and offers advice to a range of clients including government departments, statutory bodies, industry, Fisheries Local Action Groups and NGOs.


Learn more about our work in the Fisheries and Aquaculture industry.