Invasive crayfish as drivers of fine sediment dynamics in rivers : field and laboratory evidence

Auteur(s) et Affiliation(s)



Description :
This study explores the impacts of invasive signal crayfish on suspended sediment dynamics at the patch scale through laboratory and field study. Three hypotheses are presented and tested : 1) that signal crayfish generate pulses of fine sediment mobilisation through burrowing and movement that are detectable in the flow field; 2) that such pulses may be more frequent during nocturnal periods when signal crayfish are known to be most active; and 3) that cumulatively the pulses would be sufficient to drive an overall increase in turbidity. Laboratory mesocosm experiments were used to explore crayfish impacts on suspended sediment concentrations for 2 treatments : clay banks and clay bed substrate. For the field study, high frequency near-bed and mid-flow turbidity time series from a lowland river with known high densities of signal crayfish were examined. The findings indicate that signal crayfish have the potential to influence suspended sediment yields, with implications for morphological change, physical habitat quality and the transfer of nutrients and contaminants.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2014, vol. 39, n°. 2, p. 259-271, nombre de pages : 13, Références bibliographiques : 2 p.

Date :
2014

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley