Herring count in Kattegat may shape future quotas

Research vessel Dana has spent 16 days crisscrossing the Kattegat to assess herring stocks, with findings set to inform fishing quotas for 2028, Danish broadcaster DR reports.

Togt leader Susan Mærsk Lusseau and her team used sonar to detect herring and sprat, comparing echo sizes to known fish signatures to estimate population numbers. The data, collected continuously day and night, will feed into advice from the International Council for the Exploration of the Sea (ICES), which authorities use to set sustainable catch limits.

“We need to ensure we don’t take more herring than the stock can sustain for next year, while also leaving enough for whales, dolphins, seabirds, and predatory fish like cod,” Lusseau said.

The annual acoustic survey covered the Kattegat, Skagerrak, and the northeastern North Sea. Vessels from the Netherlands, Germany, Ireland, Norway, and Scotland conducted parallel counts in surrounding waters. Initial observations suggest herring schools are comparable in size to last year’s, with no immediate sign of decline or improvement.

Samples of fish were also taken to assess size, condition, and age, providing further insight into stock health. The full dataset will be processed this autumn, combined with international contributions to account for herring migration across regions.

Dana, Denmark’s largest marine research vessel, concluded this year’s survey in Hirtshals on Thursday.