Patrik Bohman, environmental analyst at the Swedish University of Agricultural Sciences (SLU), says that crayfishing has generally become somewhat delayed this year - but that the season is now underway and fishermen are getting crayfish in their traps.
It looks good, at least according to the reports I've received, he says.
The delay is partly due to weather conditions. In some parts of the country, the water level has been high, which has led to smaller catches.
But when it stabilizes, it usually becomes good fishing, says Bohman.
Small crayfish
In southern and central Sweden, on the other hand, very many crayfish have been caught that are too small - under ten centimeters, which should not be taken up. The problem concerns the signal crayfish, our invasive crayfish species, clarifies Bohman.
In Lake Vättern, there are very many crayfish, but we have a problem, and that is small crayfish. Relatively, we get up a lot of crayfish, but most of what we get up is below the minimum size.
This is a problem that has existed for several years and must be addressed, emphasizes Bohman. He believes that a large project is needed where SLU collaborates with the county administration and professional fishermen to find out why growth is not as large as it should be.
High competition
Despite the small crayfish, the summer has been good, and the catches are good, says Bohman.
It's warm temperature and a lot to eat for the crayfish. But you can imagine that in Lake Vättern, for example, when there are very many crayfish, the competition becomes high, and that means that not all crayfish will be able to grow because they don't have enough to eat.
There is thus no shortage of signal crayfish, but as for the "native" freshwater crayfish, it continues to decrease, according to Bohman.
In Sweden, there are two species of freshwater crayfish: the original freshwater crayfish and the introduced signal crayfish.
The signal crayfish is mainly found in southern and central Sweden, roughly up to the Dalälven River where the freshwater crayfish takes over. Some illegal releases of signal crayfish also exist further north, but these rarely take hold in any larger extent.
Lake Vättern is the only lake in Sweden where it is permitted for the general public to fish crayfish in public waters without special permission during limited periods.
In Sweden, approximately 2,500 tons of crayfish are fished every year, but to cover Swedes' needs, approximately the same amount needs to be imported. The imported crayfish come from, among other places, Spain, Turkey, and China.
Source: Swedish University of Agricultural Sciences
