New scientific paper highlights the sustainability issues faced when balancing pressures between maximising sustainable catch yields and ensuring effective fish stock conservation

Investigation into proposed North Sea multi-annual plans emphasises links between demersal and pelagic realms.

Scottish Pelagic Fishermen’s Association Chief Scientist, Dr Steven Mackinson, and colleagues from the Centre for Environment Fisheries and Aquaculture Science (Cefas), have published a scientific paper highlighting the sustainability issues faced when balancing pressures between maximising sustainable catch yields and ensuring effective fish stock conservation.

Investigating the proposed North Sea multi-annual management plan for demersal fish stocks, their work reveals the wider ecosystem impacts of such measures and emphasises the connectivity between demersal and pelagic fisheries, and thus, the importance of ensuring that management plans for demersal stocks are not considered in isolation from management plans for other stocks.

Taking seven years to complete, the work published in the internationally acclaimed science journal PLoS, required the researchers to develop bespoke computer modelling tools to address the complexities of the ecological and fishery consequences of the proposed management plan.

Applying ‘Management Strategy Evaluation’ procedures that employ an ecosystem model of the North Sea and its fisheries, they identify the elements of the proposed management plan that are key to its successful performance.

The paper states that the success of the measures to reduce discards outweigh the effects of other management options for controlling fishing pressure to ensure sustainable catches – but different species can show contradictory responses, and factors such as the abundance of marine predators can impact on fish stocks and the success of their fisheries.

Dr Mackinson said: “The marine ecosystem is incredibly complex and there are many interacting factors affecting fish stock biomass, some subtle and others less so. The key message from our paper is that the way discarding practices are managed would have the biggest influence on whether the proposed North Sea multi-annual plan is likely to achieve its aim for sustainable fisheries.”

Mackinson S, Platts M, Garcia C, Lynam C (2018) Evaluating the fishery and ecological consequences of the proposed North Sea multi-annual plan. PLoS ONE 13(1): e0190015