Cod populations show signs of recovery in Baltic Sea as hatchery project continues

Overfishing and oxygen depletion due to eutrophication have severely impacted cod populations in the Baltic Sea. A fishing ban has been in place for the past five years to aid recovery. The Recod project aims to artificially restore cod stocks by releasing hatchery-raised cod into the wild. Wild-caught cod have been spawned in tanks at a research facility in Gotland. Once the eggs hatch, the juvenile cod are released in suitable locations in hopes of adults being captured later.

Recent experimental fishing in the Tvären fjord near Studsvik, Södermanland, has revealed the first signs of cod in the area in three decades. However, preliminary DNA tests could not confirm that these were the released larvae. Project leader Johanna Fröjd expressed disappointment, noting that clearer results were hoped for, but emphasized that they have not given up: “This could help the cod in the Baltic Sea.”

The project has released between 1 to 1.5 million larvae each summer. Fröjd acknowledged that for the method to effectively re-establish cod in the Baltic Sea, much larger releases would be necessary. “The sea is vast, and we will never reach such a scale, but this could be a way to assist cod recovery,” she stated. The ongoing efforts signify a critical step in addressing the ecological challenges faced by this essential fish species in the region.