Report on the impacts of fisheries on stocks and landings under existing management plans

Effective management is crucial to facilitating the long-term sustainability of fisheries. This means ensuring healthy fish stocks and an environment where fishers can continue to catch valuable seafood both now and into the future. Different management approaches will have a range of effects on the catches landed by fishers, and lead to different outcomes for fish stocks and fishing livelihoods, which in turn will have an impact on future catches and the viability of fishing communities.  

Analysing the potential impacts of these different management strategies can help predict changes in landings and stocks over time, and reveal which strategies provide a win-win for fish and fisheries under Ecosystem Based Fisheries Management (EBFM). When compared to continuing fishing at current levels, evidencing the benefits and trade-offs of different management strategies can help inform policy decisions that work for fish and people in the long term.

SEAwise research

Conducted as part of our Evaluation of Fisheries Management Strategies in an Ecosystem Context theme, in this report we analysed the impacts of different management scenarios on stocks and landings, over time, across our four case study regions: the North Sea, Baltic Sea, Mediterranean Sea and Western Waters (Bay of Biscay and Celtic Sea). This analysis was based on earlier modelling work carried out as part of SEAwise. Four different management measures were simulated in the modelling scenarios carried out across these regions:

  • Status Quo – under which current fishing effort levels are maintained.
  • Landing Obligation (MSY) –  whereby quotas are set at or below maximum sustainable yield (MSY) and fleets adhere to a strict landing obligation, meaning they must land all catches and stop fishing once their first quota has been exhausted. 
  • Landing Obligation (PGY) – where fleets adhere to a landing obligation but catches are set based on sustainable MSY ranges, thus introducing more flexibility. 
  • No Landing Obligation (MSY) – landing obligation is not implemented, but catches are set at MSY. 

Here’s a snapshot of the key findings across the regions: 

  • Stocks fared better under the three alternative scenarios when compared with the status quo. For several stocks, the number of mature fish increased significantly under strict implementation of the landing obligation and MSY and this increase continued in the medium to long term. 
  • Landings increased or remained constant across all scenarios. Most increases were low, but this was region and stock dependent, and the analysis indicated large increases for some stocks currently outside of safe biological limits (e.g. cod in the Baltic Sea). 
  • At fleet level, there was little change in landings across the scenarios. However, for some fleets a large increase in landings was seen in the Celtic Sea and Baltic Sea under the landing obligation (MSY). Across other scenarios this increase was less pronounced, though the no landing obligation (MSY) scenario provided large increases in landings in the medium to long term.
  • The landing obligation (PGY) scenario did not solve the problem of choking, whereby a fishery closes once the total allowed catch of the first species is caught, resulting in lost fishing opportunities. 

Overall, our analysis indicates that the impacts of these strategies were stock, fishery and regionally dependent.

What happens next?

The findings of this report will now feed into our EBFM Tool and Toolbox. We will also look to continue improving the mixed fisheries and ecosystem models using enhanced submodels developed across SEAwise and further define and test management strategies.

Read the full report here.

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