Baltic herring

Baltic herring (Clupea harengus membras) is a subspecies of the Atlantic herring (Clupea harengus) which has adapted to brackish water. It grows more slowly and has a lower fat content than its Atlantic counterpart. Baltic herring stocks consist of several distinct local stocks and populations in the Baltic Sea. Some of the populations move between the Baltic and the North Sea including the fast-growing herring that spawn around Rügen Island off the northern German coast. After spawning these fish migrate into Skagerrak and the North Sea for the summer, before returning to the Sound and German waters for the winter.

The reported annual herring landings in the Baltic Sea have been at the level of 250,000 - 440,000 tons during 1970-2007. The herring stocks in the Gulf of Riga and Bothnian Sea can in suitable conditions form high densities as these fairly small water areas have had annual landings of over 100 000 tons/year. On the other hand, the herring stocks in the Baltic Proper and the Gulf of Finland have lately suffered from low growth rates and the general condition of herring individuals has been poor. This has been seen in the recent catches.

Source: http://ec.europa.eu/fisheries/press_corner/press_releases/com07_57_graphs_en.pdf

Most Baltic herring populations spawn in the spring, but autumn-spawning populations occur all over the Baltic Sea. The autumn-spawning Baltic herring was abundant in the first half of the 20th Century, but has been scarce since the 1960s. The catches of autumn-spawning herring have annually been approximately 5000 tons/year.

Herring is currently managed by five separate management units. The current level of exploitation of the Baltic herring stocks seems to be sustainable in all of the five management units, however recent ICES advice (report/2008/Baltic Sea) warns of missing stock reference points. The reported landings in the Baltic proper and in the Gulf of Finland (ICES 25–29+32, excl. Gulf of Riga) have been below the TACs in 1992-2002 and fishing pressure has been rather low in the recent 15 years. According to ICES advice, herring TAC in these areas should be less than 147,000 tons. Herring stock in the Baltic proper is growing slowly. Other herring fisheries (in the Gulf of Riga, Bothnian Sea and Bothnian Bay) should be managed according to the precautionary limits. In the Bothnian Sea landings should be less than 67,000 tons in 2009.