Balticsea 2020

Cod in the Åland Sea

For many years cod has been captured in the Åland Sea, but because of the low salinity no one has believed that it is actually a separate population that spawns and reproduces in the area. However, there is evidence to suggest that this is true. In the project "Cod in the Åland Sea" the Swedish University of Agricultural Sciences (SLU) will work on a genetic study to clarify whether the cod in the Åland Sea is different from other cod stocks in the Baltic Sea.

East and north of Bornholm has been known for areas where cod thrives to spawn; Bornholm Basin, Gdansk Deep and the Gotland Basin. Because of the lack of oxygen the cod now days only spawn in the Bornholm basin. During the summer cod has been caught in the Åland Sea, but because of the low salinity levels the eggs cannot survive.

In 2012 and 2013, SLU collected samples of cod from the area which indicated that the cod stock in the Åland Sea seems to be a separate population. The samples shows e.g. that cod is not worm infected as in the southern Baltic, but it also shows differences in size and shape.

To clarify whether the cod in the Åland Sea constitutes a separate spawning stock and adapts to the low salinity in the area, SLU will perform a genetic study of the samples collected. A combination of several different types of genetic markers will be used.

The results of the project will be summarized in a scientific article. If the study shows that the cod in the Åland Sea is showing signs of an independent spawning, an information campaign will be directed to relevant groups within ICES and The Swedish Agency for Marine and Water Management, to discuss appropriate management measures that can ensure a long-term fish population.