Management of the whitefish gillnet fishery in Kvarken

The regulations of the whitefish fishery are about to change, with the smallest allowed mesh size (measured as 'knot to knot') of gillnets being increased to 45 mm in the Gulf of Bothnia, including Kvarken. The regulations are needed to reduce the high fishing mortality of the endangered river-spawning whitefish ecotype ("maraena whitefish"). Thus far, the smaller mesh size has enabled fishery on the smaller-sized sea-spawning ("Valaam") whitefish. Based on the age distribution of the specimens of this ecotype, its fishery has been at a sustainable level.

This project investigates, in cooperation with commercial fishers, the scope for the continuation of a targeted fishery for the sea-spawning whitefish ecotype with the smaller 40 mm ('knot to knot') gillnet mesh size. For this purpose, the project is assessing the distribution of the whitefish ecotypes in the gillnet catches in Kvarken, in relation to the fishing area, time and depth.

The project will generate novel knowledge on the scope for regional and temporal fishing regulations, and therefore its results can be used for knowledge-based adjustments of the whitefish fishery regulations.