A typology of fish communities in French lakes. II. Fish assemblages in lakes below 1500 m in altitude.

Few research has been carried out on French lacustrine fish communities. In a first part, we presented the results obtained by analysing fish communities in natural lakes and reservoirs located over 1500 m in altitude (ARGILLIER et al., 2002b). The present article follows a similar analytical approach but deals with lowland sites. Both natural and man-made lakes display a fish gradient from upstream to downstream sites. The species range from gudgeon, rainbow trout and brown trout, then pike and roach, perch and eventually pikeperch. The distinction between the fish communities of natural lakes and reservoirs relies upon the abundance of several species. Whitefish and arctic charr are lake dwellers whereas the abundances of black bullhead, French nase and barbel are maximum in reservoirs. The fish communities can be related to the location of the sites in their catchment. Some results suggest that the physical features of littoral habitats could contribute to explain the observed communities. Further works should take into consideration complementary descriptors of both fish communities and environmental features.