Consequences for lotic ecosystems of invasion by signal crayfish
Abstract
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.
Authors
Hayes, Richard BirchallCollections
- Theses [4490]