1. Environment Canada, Canada Centre for Inland Waters; 867 Lakeshore Blvd., P.O. Box 5050 Burlington ON L7R 4A6 Canada
2. Environment Canada, National Hydrology Research Centre; 11 Innovation Blvd. Saskatoon SK S7N 3H5 Canada
3. Environment Canada and Canadian Rivers Institute; Dep. Biology; Univ. New Brunswick; 10 Bailey Dr., P.O. Box 4400 Fredericton NB E3B 5A3 Canada
4. Environment Canada and Agriculture and Agri-Food, Canada, Potato Research Centre; 850 Lincoln Rd., P.O. Box 20280 Fredericton NB E3B 4Z7 Canada