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Research article - Peer-reviewed, 2015

Multiple drivers of decline in the global status of freshwater crayfish (Decapoda: Astacidea)

Richman, Nadia I.; Edsman, Lennart; Collen, Ben


Rates of biodiversity loss are higher in freshwater ecosystems than in most terrestrial or marine ecosystems, making freshwater conservation a priority. However, prioritization methods are impeded by insufficient knowledge on the distribution and conservation status of freshwater taxa, particularly invertebrates. We evaluated the extinction risk of the world's 590 freshwater crayfish species using the IUCN Categories and Criteria and found 32% of all species are threatened with extinction. The level of extinction risk differed between families, with proportionally more threatened species in the Parastacidae and Astacidae than in the Cambaridae. Four described species were Extinct and 21% were assessed as Data Deficient. There was geographical variation in the dominant threats affecting the main centres of crayfish diversity. The majority of threatened US and Mexican species face threats associated with urban development, pollution, damming and water management. Conversely, the majority of Australian threatened species are affected by climate change, harvesting, agriculture and invasive species. Only a small proportion of crayfish are found within the boundaries of protected areas, suggesting that alternative means of long-term protection will be required. Our study highlights many of the significant challenges yet to come for freshwater biodiversity unless conservation planning shifts from a reactive to proactive approach.


extinction risk; crayfish; IUCN Red List; threatened; freshwater biodiversity

Published in

Philosophical Transactions B: Biological Sciences
2015, volume: 370, number: 1662, article number: 20140060
Publisher: ROYAL SOC

Authors' information

Richman, Nadia I.
Zoological Society of London
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Collen, Ben
University College London

Associated SLU-program

Lakes and watercourses

Sustainable Development Goals

SDG15 Life on land
SDG14 Life below water

UKÄ Subject classification


Publication Identifiers


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