Benthic macroinvertebrates in the Nishina Three Lakes and Lake Nojiri, highland lakes in Japan Benthic macroinvertebrates in the Nishina Three Lakes and Lake Nojiri, highland lakes in Japan (Proceedings of the 14th International Symposium on River and Lake Environments (ISRLE2009))

order to clarifythe current status of the benthic communities in the Nishina Three Lakes (Lakes Aoki, Nakatsuna and Kizaki) and Lake Nojiri, highland lakes located atthefoot of the Japanese Northem Alps in Nagano Prefecture, We collected benthic macroinvertebrates on 1 and 2 August, 2007, Chironomidaeand Oligochaeta were the major CrOinvertebrates at all study sites and the taxonomic composition of Chironomidae was differentamong the sites. Sergentia was collected in Lakes Aoki andKizaki, whereas Chironomus was collected in all the lakes except Lake Aoki. Chaoboridae was collected at the center of the Lakes Nakatsunaand Kizaki but not in Lakes Aoki and Nojiri. The comparison of the densities of benthic maroinvertebrates with the previous studies suggests that the densities of Oligochaeta increased in Lakes Aoki,Kizakiand Nojiri, and Chironomus increasedinLake Nojiriin recent decades.