Rostherne Mere, England, A Further Instance of Guanotrophy

Abstract

Rostherne Mere, Cheshire, England, is a small lake with a maximum depth of about 30 m. It is a normal dimictic eutrophic lake with a diverse benthic fauna, but the sediments of the deepest part of the lake are permanently deoxygenated and are devoid of organisms other than copepods, probably in a dormant state. In the absence of any significant organic pollution from human sources, this condition is attributed to the deposition of faeces from the very large bird population on the lake, both resident and transitory.