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Title: Eradication of Alien Crayfish Populations
Author: Peay Stephanie
Author: Environment Agency
Document Type: Monograph
Annotation: Environment Agency Project ID:EAPRJOUT_666, Representation ID: 226, Object ID: 1998
The report concludes that: - None of the methods attempted in the field showed any realistic potential of achieving the objective of this R & D project, to eradicate or control signal crayfish populations. - Control with biocides was found to be the only eradication method with this potential. This technique carries a range of adverse side effects. - A sampling method which is capable of detecting signal crayfish at population densities that threaten native crayfish (less than 1 adult per 500 m2 of riverbed) is required. - Research into control methods with no potential for reducing crayfish population density below the minimum viable population density (MVPD), should be discontinued. - It is anticipated that all white-clawed crayfish resident in catchments also containing signal crayfish will be lost, unless a very substantial upstream barrier such as a large dam restricts upstream migration. Current legislation will not protect white-clawed crayfish in native-only catchments from either accidental destruction or future introductions of signal crayfish. - Conservation effort should focus on the use of poisons when necessary to protect native-only catchments, and the establishment of isolated ‘refuge sites’ for white-clawed crayfish. - A discussion should be conducted on the relative environmental consequences of allowing signal crayfish to expand their range, or of eradicating selected populations with biocides. The output of this discussion would guide future efforts at controlling alien crayfish. Nonetheless, the finding of this study is that in very many catchments alien crayfish populations are already too well established for there to be any realistic prospect of eradication or control.
Publisher: Environment Agency
Subject Keywords: CrayfishRiversPest controlCrustaceaFungal diseases
Taxonomic Keywords: PacifastacusAustropotamobiusPacifastacus leniusculusAustropotamobius pallipesAphanomyces astaci
Extent: 122
Total file downloads: 24

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