A typology of fish communities in French lakes. I. Fish assemblages in mountain lakes (over 1 500 m altitude).

Most of the investigations carried out on the relationship between lake fish community structure and environmental variables originate from Northern America. In our study, fish assemblages in French natural and man-made lakes were studied and related to the sites characteristics. Species relative abundance were collected on 98 lakes and processed by Correspondence Analysis. It showed a clear distinction between altitude (>1500 m) and lowland sites (<1500 m) that were therefore analysed separately in a second stage. Mountain lakes and reservoirs display poor fish diversity (mean=2) and can be classified on the basis of their dominant Salmonid species. Species abundances are not correlated to the environmental variables but are more likely to reflect fishery management practices.