Swedish Agency for Marine and Water Management

In a decision of 30 March 1995, the Government commissioned the National Board of Fisheries, in consultation with the National Environmental Protection Agency, to compile documentation concerning the situation of naturally reproducing salmon in the Baltic Sea.

Original Baltic natural salmon has been severely decimated during the 20th century owing to the expansion of hydroelectric power in their growing waters. There used to be a natural occurrence of salmon in about 70 watercourses round the Baltic Sea. Natural salmon populations remain today in about 26 rivers (14 Swedish, 1 Swedish-Finnish, 1 Finnish and the rest Baltic).

A comprehensive compensatory programme has been built up for the harnessed rivers as a replacement for the natural salmon production that has disappeared with the expansion of hydroelectric power. Salmon reproduction in the harnessed river is replaced through this programme by rearing of young salmon up to the size when they normally go out to sea. Today only one salmon in ten in the Baltic Sea is a natural salmon, while the rest are reared. Reared salmon has other characteristics than those that originally were favourable in natural conditions. From having coped with river life for 1-4 years before migrating out to sea, the salmon has changed to a form partially adapted to rearing, with a modified genetic base. By artificially maintaining salmon stocks in the Baltic Sea at a constantly high numerical level, salmon fishery has been able to continue and has even been intensified. Natural salmon is then caught to an equally great extent as cultivated.

Adult salmon remain in the Baltic Sea for a great part of their growth period. The longer it takes the salmon to return to natural spawning waters in the river, the more it is exploited. Estimates show that no more than a quarter of the possible production of natural salmon round the Baltic Sea is used, which can be regarded as a waste of resources, in both the short and the long term.

Internationally determined catch quotas in the Baltic Sea, together with measures taken by the National Board of Fisheries in the form of closed seasons, closed areas, restrictions on gear and redemption of fishing traps, resulted in an increase of natural salmon stocks from the end of the 1980’s. The situation deteriorated, however, when M74 struck salmon stocks in 1992-93. One decisive problem is that salmon is caught internationally. Even though its spawning rivers are exclusively in Sweden, and to some extent in Finland and the Baltic states, it migrates to sea and resides as an adult all over the Baltic Sea. Swedish restrictions and efforts alone are therefore not sufficient. Swedish measures must be combined with reduced international exploitation of natural salmon in all areas. The strain on the Baltic Sea of environmental pollution is at the same time an international problem.