Adaptive Management of Noble Crayfish (Astacus astacus)
Published Online: 12/10/2013
Abstract
During 1979–1981, a simple and non-expensive monitoring programme for crayfish was developed in Lake Steinsfjorden. From the programme, which includes data on total trapping effort, catch statistics and population composition from test fishing before and after the fishing season, we have estimated yield and monitored population development since 1979. Based on data from the monitoring programme, an adaptive management scheme was introduced for the crayfish population. The results from the monitoring programme have been the basis for authorities when adopting changes in the management scheme and revealing the effects. High exploitation, catching non-legal sized crayfish, low fraction of mature females and the spread of Canadian pondweed have all challenged crayfish management regulations in Lake Steinsfjorden. Management regulations have changed several times during the study period. The major changes included reducing the trapping season from 147 to 7 days, a measure that is easy to enforce, and increasing the mesh size of traps from 17.5 mm to 23 mm. In spite of these measures, the harvest declined by 75%, mainly due to the Canadian pondweed invasion, as this plant now occupies a large part of the shallow areas in the littoral zone.
Supplemental Documents
There are no supplementary documents for this article

Cited By
Citations:
How to Cite
Skurdal J, Garnås E and Johnsen SI. (2013). Adaptive Management of Noble Crayfish (Astacus astacus). Freshwater Crayfish 19(2):145-151. doi: 10.5869/fc.2013.v19-2.145
Author Information
Jostein Skurdal, Human Dimension Department, (1) Norwegian Institute of Nature Research, Fakkelgården, Lillehammer, , Norway2624. E-mail: jostein.skurdal@nina.no
Erik Garnås, Environmental , (2) Buskerud County Administration, , Drammen, , Norway3007. E-mail:
Stein I. Johnsen,* Human Dimension Department, (1) Norwegian Institute of Nature Research, Fakkelgården, Lillehammer, , Norway2624. E-mail: stein.ivar.johnsen@nina.no
Corresponding Author indicated by an *.
Publication History
Manuscript Submitted: 4/15/2013
Manuscript Accepted: 10/21/2013
Published Online: 12/10/2013
Published in Print: 12/10/2013
Funding Information
No specific funding statement is available for this article.