There have been drastic changes to the Baltic fish populations causing ripple effects for the entire Baltic Sea ecosystem as well as causing changes to lower levels of the food chain and contributing to other problems such as eutrophication.
Overfishing does not only deplete the specific fish caught, it also changes the sea’s food web structures. Predators, such as seals and seabirds are affected negatively when the fish they normally eat decrease, while prey fish and organisms increase and take over as their natural predators like cod in the Baltic Sea disappear.
Fishing in the Baltic Sea is regulated by the European Common Fisheries Policy. Specific quotas are set for each of the most important commercial species. Because the quotas historically have been higher than the reproductive capacity of the ecosystem, they have led to decreased or depleted fish stocks. Overfishing also occurs through by-catch and illegal fishing.