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Title: Consequences for lotic ecosystems of invasion by signal crayfish
Author: Hayes, Richard Birchall
ISNI:       0000 0004 2721 958X
Awarding Body: Queen Mary, University of London
Current Institution: Queen Mary, University of London
Date of Award: 2012
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Non-native invasive species are major drivers of biodiversity loss and ecosystemlevel modification. The signal crayfish (Pacifastacus leniusculus) is a highly successful invasive species and demonstrates traits often seen in keystone species, including top-down predatory effects, a high degree of omnivory, and an ability to physically modify its habitat. From field surveys, and in situ and artificial channel experiments, I show that signal crayfish have direct and indirect impacts on the benthos, as well as ecosystem process rates, in lowland, chalk stream ecosystems. Furthermore, I show that these effects are often dependent on crayfish life stage. I demonstrate that two native fish species (chub, Leuciscus cephalus and bullhead, Cottus gobio) may be affected positively, as well as negatively, by signal crayfish invasion. In addition, population genetics reveals overall high levels of genetic diversity in populations of signal crayfish in the UK.
Supervisor: Not available Sponsor: Queen Mary University of London ; Environment Agency
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: Biology