1. Canadian Rivers Institute, Department of Biology, University of New Brunswick, P.O. Box 5050, Saint John, New Brunswick, E2L 4L5
2. National Environmental Effects Monitoring Office, Environment Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan, S7N 3H5
3. Applied Statistics Center, Department of Mathematics and Statistics, University of New Brunswick, P.O. Box 4400, Fredericton, New Brunswick, E3B 5A3, Canada