Using Chironomidae and Cladocera in sediment records to evaluate ecosystem effects of fish introduction in four mountain lakes of the Pyrenees

Abstract : Mountain lakes have developed a significant role for the economy of human local populations during the past centuries, particularly as fish suppliers. Because fish introductions in previously fishless lakes have been performed for centuries (Fig. 1), in some cases dating back to the XIV century 1 , it is interesting to analyse their effects on palaeolimnological records, compared to that of climate and/or nutrient enrichment. This question is relevant to adjust management strategies for mountain lakes. Here, we propose the use of subfossil remains (i.e. Chironomidae and Cladocera) to evaluate the effects of fish introductions on the invertebrate communities in lakes.