EU-funded researchers have developed new indicators to determine fisheries' maximum sustainable yields that fully respect ecological, economic and social sustainability. These indicators will feed into Europe's fisheries management plans for all regions.
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The MSY (maximum sustainable yields) concept is about identifying the highest possible catch of a species that can be taken without negatively impacting future fish numbers or the ecosystem. MSY is a cornerstone of the EUs Common Fisheries Policy (CFP) in fact the concept has been used for 50 years to manage fisheries and ultimately aims to provide EU citizens with a long-term, sustainable, secure and healthy food supply.
The MYFISH team established indicators for determining MSY that take into account ecological, economic and social sustainability. A key reason for the projects success was that it acknowledged the difficulties fisheries face in calculating MSY. Fish stocks vary over time, affected by complex factors.
In real life of course the fishing industry has to deal with a whole host of variable factors; fish eat each other and end up as lunch for seabirds and marine mammals, explains project coordinator Anna Rindorf from the Technical University of Denmark. The marine environment is constantly changing. And quite often, the fishing effort required to attain MSY of one species exceeds that required to attain MSY of another species caught in the same fishery.
The projects indicators will now be used to inform new multiannual implementation plans (the EU term for fisheries management plans) for all regions. The MYFISH team also created new user-friendly guides on how fisheries can make decisions that take into account these important economic, ecological and social aspects.
We found that the specific characteristics of individual fisheries should be considered when developing plans, says Rindorf. These plans also need to explain trade-offs in a way that is easily understandable to users.
Fishing for input
This work was defined with the involvement of a wide range of stakeholders from industry and NGOs to managers. Importantly, MSY now encompasses both maximum economic yield and sustainability criteria, such as the desire to maintain and preserve sensitive species, as well as to support employment, explains Rindorf.
The project analysed fisheries in the North Sea, the Baltic Sea, the Mediterranean Sea and western waters, which include the Celtic Sea, Irish Sea, Bay of Biscay and Iberian Sea. From this, the project team was able to demonstrate first-hand the challenges that fisheries face, as they encountered significant changes in many stocks over the three years.
One example is the Baltic Sea eastern cod stock, which experienced severe growth and even survival problems, says Rindorf. This made many of the existing models we use invalid.
Data collected during fieldwork also supported a greater role for the Pretty Good Yield (PGY) concept. PGY is defined as a sustainable yield of at least 95 % of the maximum sustainable yield, and is generally obtained over a broad range of stock sizes.
In the meantime, by making the MSY concept fully operational and responsive to real life conditions at sea, MYFISH, which was completed in February 2016, has made a long-term contribution towards achieving sustainable fishing and maintaining healthy fish stocks, ecosystems and industries. But the work of the fisheries management researcher is not yet done. The process to implement the multiannual plans continues, as does the task of continuously updating management to reflect ecosystem changes, says Rindorf.