Every year, large amounts of hatchery-raised young salmonids are released into Swedish rivers and streams to compensate for losses in natural production. Butthese fish generally survive poorly in the wild.. Researchers at the
Salmonids constitute an important natural resource in
Sofia Brockmark, researcher at the Department of Zoology, has studied how the hatchery environment can be improved to increase the survival of the released fish. Her thesis, which will be publicly defended on 18 December, shows that young salmon fish that are less crowded in the hatchery manage the transition more successfully. 'The combination of high density and lots of affects their development. Our experiments show that salmon fish raised in a more spacious environment, meaning it is more similar to nature, are better at adapting to life in rivers and streams,' says Brockmark.
The research will now be developed further in the SMOLTPRO project, which recently received 20 million SEK from the Swedish Research Council Formas. The project is led by Professor Jorgen Johnsson at the Department of Zoology and is coordinated from the
The researchers will use full-scale models in the different zones in the Baltic Sea, the Kattegat and the
An additional hypothesis is that hatchery-raised salmon are fed too much and that their diet is too high in fat. This may make them too fat to be able to adjust successfully. The results of the project will, following a dialogue with several public actors, be used to develop new recommendations on how to make the production of hatchery-raised smolts more ecologically sustainable and ethical. The project is directly linked to the strategic efforts of Formas and the Swedish Government to develop aquaculture practices and attain sustainable management of natural resources.