10 September 2013

Turning the tide

Marmorkrebs are a concern as an emerging invasive crayfish, but in much of the world, they still have a long way to go before they catch up with other exotic crayfish. In North American, a lot of attention has revolved around the rusty crayfish, Orconectes rusticus.

This article describes an effort to control rusty crayfish in a semi-natural setting that seemed to have worked. The abstract reports that they reduced the number of crayfish by 99% of where they started. The paper goes on to look at what happens to the lake when the crayfish are gone. As I’ve often said to people, “A lake with crayfish looks completely different than one without crayfish,” and this research bears that out.

How did the team get this invasive crayfish under control? Trapping, and a lot of elbow grease (my emphasis).

Hansen thinks that, if the right agency or lake association had the time and money to pay someone to extensively trap crayfish, it could work. But, she cautions, it’s a lot of work. Her group needed eight summers of full-time trapping to finally get rusty crayfish numbers where they wanted them.


Hansen GJA, Hein CL, Roth BM, Vander Zanden MJ, Gaeta JW, Latzka AW, Carpenter SR. 2013. Food web consequences of long-term invasive crayfish control. Canadian Journal of Fisheries and Aquatic Sciences 70:1109-1122. http://dx.doi.org/10.1139/cjfas-2012-0460

External links

In whole-lake experiment, have invasive crayfish met their match?

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