Sea trout (Salmo trutta) in subdivisions 22–32 (Baltic Sea)

The Baltic Sea contains approximately 1000 sea trout stocks and about half of them are wild. There are no estimates of the historical numbers of sea trout populations or quantitative estimates of the total natural smolt production in past years. The status of these populations is very variable; a few populations appear to be in a good state, whereas in 6 of the 9 ICES subdivisions the status is below the estimated potential abundance (taking latitude and river size into account) if the river habitat was good and the populations stable (Figure 8.4.16.1).

Densities of 0+ parr observed in electrofishing surveys show highly variable recruitment (Figure 8.4.16.2). Differences in densities are influenced by latitude, river size and habitat quality. Taking these into account, trout populations are on average much below potential especially in subdivisions 26, 28, 29, 31 and 32 (Figure 8.4.16.1). River catches for the Bothnian Bay area are also highly variable and have declined sharply since the 1960s (Figure 8.4.16.3). This is accompanied by a marked decline in the age of fish caught in this area (Figure 8.4.16.4).

The nominal sea trout catch from the Baltic Sea was 558 tonnes in 2008, which is 348 tonnes (38%) less than in 2007 (Table 8.4.16.1).