Conservation of the White-clawed crayfish Austropotamobius pallipes in the face of invasive non-native species pressures

Biodiversity and Ecology

UCL

KCL

Great Britain has one native crayfish species, the White-clawed crayfish Austropotamobius pallipes. A. pallipes has undergone extreme population declines since the 1970s, due to habitat degradation, pollution and more recently invasive crayfish species, such as the Signal crayfish Pacifastacus leniusculus, influencing the strategies needed to conserve the remaining populations. An important potential conservation technique for White-clawed crayfish is the use of ark sites. Ark sites allow for the establishment of self-sustaining bio-secure White-clawed crayfish populations, isolated from Signal crayfish and the associated fungal pathogen Aphanomyces astaci, or ’Crayfish Plague’. The initial establishment of ark sites has critically supported A. pallipes conservation science, however much remains undefined about the ecological requirements for a successful ark site. Researching the impacts of the invasive P. leniusculus can be crucial in understanding both species-specific and ecosystem wide consequences. Headwaters provide key habitat for spawning fish, often provide final within-catchment refuges for populations of A. pallipes, and influence downstream ecosystem dynamics. The comparative impact of P. leniusculus and A. pallipes on native ecological communities in headwaters requires research. A combination of conservation measures for A. pallipes and active management of the invasive P. leniusculus is advocated to provide A. pallipes with a secure future.

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