The large-scale Swedish trawling for herring in the Baltic Sea has flourished in recent years. The herring catches in the Central Baltic and the Bothnian Sea have increased by 70 percent over the past five years. At the same time, a larger proportion of the fishery has moved closer to the east coast.
There are now worrying reports about a decreased abundance of herring in several coastal areas. These concerns include depletion of local herring subpopulations, with grave consequences for coastal ecosystems and lower productivity of the whole herring stock.
These signals from the coast, and the overall negative trends for some of the major Baltic Sea herring stocks, call for caution. Fisheries management and stock assessment frameworks should urgently ensure a better and more detailed understanding of 1) the stock- and subpopulation structure of the Baltic Sea herring, and 2) how the current herring fishery affects the coastal ecosystems.
In order to halt the negative development, it is also necessary to restrict the large-scale trawling for herring close to the Swedish east coast, in line with the precautionary approach.
Policy recommendations
• Move the trawling border along the Swedish east coast further out (e.g. to 12 nautical miles from the baseline) to secure herring spawning sites and overwintering areas.
• Conduct a more detailed survey of the stock and subpopulation structure and migratory patterns of the Baltic Sea herring, using historical knowledge and new DNA-techniques, cross-checked with other techniques, such as otolith chemistry.
• Use the survey results to revise the current structure of management units for Baltic Sea herring to better account for herring subpopulations in fisheries management.
• Reduce annual catches to well below Fmsy for Central, Western, and Gulf of Bothnia herring – to safeguard the preservation of stocks, subpopulations, and genetic diversity.
• Restrict large-scale herring trawling in times and places with particular risks for coastal ecosystems and local subpopulations, in line with the precautionary principle.
Read the full web version of the policy brief at Baltic Eye or download your copy here:
Reduce coastal trawling to protect the Baltic herring (361 Kb)
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References to policy brief: Reduce coastal trawling to protect the Baltic herring (790 Kb)
CONTACT
Henrik Svedäng, Reseracher at the Baltic Sea Centre
Charles Berkow, Advocacy and Analysis Officer at the Baltic Sea Centre