Swedish native crayfish face critical decline as invasive signal crayfish spreads

A warm spring and a favourable summer have created optimal conditions for this year's crayfish season in Sweden, according to Martin Karlsson of the Swedish Agency for Marine and Water Management. However, the native freshwater crayfish (flodkräfta) is listed as critically endangered. The invasive signal crayfish, introduced in the 1960s‑1970s to offset earlier declines, carries the crayfish plague without showing symptoms, accelerating the loss of native populations.

Patrik Bohman, environmental analyst at the Swedish University of Agricultural Sciences (SLU), notes that illegal releases of signal crayfish continue to threaten the remaining native stocks, of which fewer than 800 viable populations remain out of more than 10,000 total crayfish sites. The species is strongly protected under Swedish law, and fishing is regulated to help preserve the remaining stocks. Experts advise sustainable fishing and the continuation of traditional crayfish feasts as part of conservation efforts.