Whitefish in the Gulf of Bothnia

The abundance and amount of fishing of sea-spawning and migrating whitefish stocks in the Gulf of Bothnia are being monitored with the help of beach seining, catch samples and catch statistics. The FGFRI can issue recommendations for changes in fishing regulations on the basis of this information.

Signs of overfishing can be seen in the migrating whitefish stocks in the Gulf of Bothnia. Gillnet fishing, for example, which is the most important fishing method for whitefish, harvests half-grown whitefish because the nets are too dense. The mean size of whitefish ascending the rivers has decreased particularly in the northern areas of the Gulf of Bothnia.

The mean age of spawning stock has risen, because the proportion of fast-growing whitefish in the population has decreased as a consequence of selective fishing. Fast-growing whitefish have a greater chance of being caught in gillnets before reaching maturity. The proportion of females in the population ascending the rivers has also decreased. Females stay in feeding grounds 1-2 years longer than males, and are thus more often caught before spawning than males.

Collecting whitefish fry samples with a beach seine

Scientist in charge of project

Erkki Jokikokko
Finnish Game and Fisheries Research Institute
Bothnian Bay Fisheries Research Station
Jenssintie 2
FIN-95200 Simo, Finland
Phone +358 - (0)205 751 811
Fax +358 - (0)205 751 819
e-mail: firstname.lastname@rktl.fi

Other research staff: Alpo Huhmarniemi, Ari Leskelä

Duration: continuous

Text version