In a new report, SLU's researchers at the Freshwater Laboratory in Drottningholm state that the crayfish in Lake Vättern are becoming more, but smaller.
The researchers believe that fishing is too hard in Lake Vättern and see problems for commercial fishermen in the long run.
This is a difficult issue financially, as commercial fishermen in Lake Vättern have become dependent on crayfish fishing.
90 percent
The supply of signal crayfish has increased sharply in Lake Vättern since 2000 and thus also the crayfish fishery.
Today, crayfishing, which takes place over a few weeks, accounts for as much as 90 percent of commercial fishermen's income.
- It is only during six weeks from the last week in July and one week into September that there is demand.
Everyone wants to eat at the same time in August.
We ourselves thought when it was released 20 years ago that it would be possible to fish all year round, but there is no demand then, but then it is frozen crayfish that applies.
Too hard fishing
The researchers at SLU Aqua interpret the situation with more but smaller crayfish as meaning that the crayfish fishing is too hard, especially in the northern part of Lake Vättern.
- Actually, you want some form of regulation so that the fishing pressure is reduced, says Rolf Gustavsson.
Hear the fisherman Rolf Gustavsson's comments on SLU's report in the video above.