1. Lancaster Environment Centre, Department of Environmental Science, Lancaster University, Lancaster LA1 4YQ, UK, National Water Research Institute, Environment Canada, 867 Lakeshore Road, P.O. Box 5050, Burlington, Ontario, Canada L7R 4A6, Science and Technology Branch, Environment Canada, 4905 Dufferin Street, Downsview, Ontario, Canada M3H 5T4, Cambridge Environmental Assessments, Battlegate Road, Boxworth, Cambridge, B3 8NN, UK, and Department of Environmental Assessment, Swedish University of...