1. Center for Fisheries, Aquaculture and Aquatic Sciences, 1125 Lincoln Drive; Southern Illinois University; Carbondale IL 62901-6511 U.S.A.
2. Environmental Sciences Division, Oak Ridge National Laboratory; One Bethel Valley Road Oak Ridge TN 37831-6036 U.S.A.
3. North Dakota Game and Fish Department; 3001 Main Avenue Bismarck ND 58501 U.S.A.