Numerous Population Crashes of Wild Signal Crayfish (Pacifastacus leniusculus) in Southern Finland
Published Online: 12/31/2014
Abstract
The alien signal crayfish (Pacifastacus leniusculus) was introduced into Finland, and then more broadly in Europe, with the expectation that it would be a suitable substitute for the native crayfish that was eradicated by crayfish plague (Aphanomyces astaci) epidemics. Signal crayfish introductions were promoted and the initial results indicated the stocking was successful. Later, there have been several cases showing that the initial conclusions were premature, and that signal crayfish stocks were struggling in Nordic countries. Here we present the first data on wild signal crayfish population declines and crashes in Kanta-Häme, Finland, where a minimum of 29 signal populations have collapsed during the past decade (a total of 39% of stocked populations). These populations were mainly inhabiting small water bodies (less than 1000 ha) and were all commercially productive (> 1 CPUE) before the collapse. Our data indicates that success of signal crayfish introductions should only be assessed after this alien species has achieved the carrying capacity of the aquatic ecosystem. In light of our results, the early assessments of the suitability of the signal crayfish to successfully inhabit European aquatic ecosystems should be carefully reconsidered.
Supplemental Documents
There are no supplementary documents for this article
Cited By
0 Citations:
How to Cite
Jussila J, Makkonen J, Kokko H and Mäkinen P. (2014). Numerous Population Crashes of Wild Signal Crayfish (Pacifastacus leniusculus) in Southern Finland. Freshwater Crayfish 20(1):73-79. doi: 10.5869/fc.2014.v20-1.73
Author Information
Japo Jussila,* Department of Biology, University of eastern Finland, P.O.Box 1627, Kuopio, Savo, Finland70211. E-mail: japo.jussila@uef.fi
Jenny Makkonen, Department of Biology, University of Eastern Finland, P.O.Box 1627, Kuopio, Savo, Finland70211. E-mail: jenny.makkonen@uef.fi
Harri Kokko, Department of Biology, University of Eastern Finland, P.O:Box 1627, Kuopio, Savo, Finland70211. E-mail: harri.kokko@uef.fi
Petri Mäkinen, Hämeenlinna office, Häme Fisheries Advisory Center, Vanajantie 10b, Hämeenlinna, Kanta-Häme, Finland13110. E-mail: petri.makinen@proagria.fi
Corresponding Author indicated by an *.
Publication History
Manuscript Submitted: 11/6/2014
Manuscript Accepted: 12/11/2014
Published Online: 12/31/2014
Published in Print: 12/31/2014
Funding Information
No specific funding statement is available for this article.