A novel ‘triple drawdown’ method highlights deficiencies in invasive alien crayfish survey and control techniques

Autor: Eleri G. Pritchard, Daniel D. A. Chadwick, Jan C. Axmacher, Paul Bradley, Carl D. Sayer, Lawrence J. B. Eagle, Michael A. Chadwick
Rok vydání: 2020
Předmět:
Zdroj: Chadwick, D, Pritchard, E, Bradley, P, Sayer, C, Chadwick, M, Eagle, L & Axmacher, J 2021, ' A novel ‘triple drawdown’ method highlights deficiencies in invasive alien crayfish survey and control techniques ', JOURNAL OF APPLIED ECOLOGY, vol. 58, no. 2, pp. 316-326 . https://doi.org/10.1111/1365-2664.13758
ISSN: 1365-2664
0021-8901
Popis: Freshwater crayfish can be successful invaders that threaten native biota and aquatic ecosystems in numerous countries worldwide. Nonetheless, the inability of conventional crayfish survey techniques like trapping and handsearching to yield quantitative population data has limited the understanding of crayfish invasion biology and associated ecological impacts. Here, we employed a novel ‘triple drawdown’ (TDD) method to sample invasive populations of signal crayfish Pacifastacus leniusculus in a headwater stream in Northern England. The method was compared with conventional techniques of trapping and handsearching. The TDD method proved to be an effective technique with high capture efficiency, reporting signal crayfish densities from 20.5 to 110.4 animals/m 2 at our study sites. These numbers exceed any previous estimates for similar streams. The TDD showed the vast majority of individuals across all sites were juvenile or sub-adult (
Databáze: OpenAIRE
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