The effects of sand deposition upon the macroinvertebrate fauna of the River Camel, Cornwall


Mr P. M. Nuttall, Cornwall River Authority, St Johns, Western Road, Launceston, Cornwall, England.


Erosion from a tributary of the River Camel deposited an estimated 10,000 m3 of sand in the main river over a period of 2 years. The poor incidence of plants and macro-invertebrates from the river was associated with the unstable shifting nature of the sand deposits, rather than turbidity or abrasion caused by particles in suspension. Sand deposition accounted for the low diversity of invertebrate species below the tributary, and resulted in the elimination of several species which were frequent upstream. Baetis rhodani, Rhithrogena semicolorata, and Tubificidae were abundant where sand deposition had occurred.