Godtfred A. Halvorsen,^* Einar Heegaard,^** Arne Fjellheim,^*** Gunnar G. Raddum<sup>****


*</sup>Godtfred Anker Halvorsen is a research scientist at the Laboratory of Freshwater Ecology and Inland Fisheries (LFI) at the Department of Zoology, University of Bergen. He is working with the effects of acidification on the benthic fauna in general and on the non-biting midges (Chironomidae) in particular. This also includes the effects of liming of acidified waters, and natural recovery of acidified waters. His address: University of Bergen, Department of Zoology, LFI, Allégaten 41, N-5007 Bergen, Norway. godtfred.halvorsen@zoo.uib.no
^**Einar Heegaard holds a postdoc position at the Botanical Institute, University of Bergen. His research interests are biometry, species environmental relationships and species distributions. In particular he is interested in spatial and temporal distribution and dynamics of species and species assemblages. His address: University of Bergen, Botanical Institute, Allégaten 41, N-5007 Bergen, Norway. einar.heegaard@bot.uib.no
^***Arne Fjellheim is a senior scientist at the University of Bergen, Institute of Zoology. His main interests are effects of acidification and liming on freshwater invertebrates and habitat restoration in regulated rivers. His address: Stavanger Museum, Musegt. 16, N-4010 Stavanger, Norway. arne.fjellheim@zoo.uib.no
^****Gunnar G. Raddum is an associate professor at the University of Bergen. He is Head of the unit: Laboratory for Freshwater Ecology and Inland Fisheries, Zoological Institute, UiB. His main interest is effects of acidification, liming and restoration of freshwater ecosystems in general. His address: University of Bergen, Institute of Zoology, Allegt. 41, N-5007 Bergen, Norway. gunnar.raddum@zoo.uib.no