1. Department of Biology, Dalhousie University, 1355 Oxford Street, P.O. Box 15000, Halifax, NS B3H 4R2, Canada
2. Fisheries and Oceans Canada, Bedford Institute of Oceanography, 1 Challenger Drive, P.O. Box 1006, Dartmouth, NS B2Y 4A2, Canada
3. Ocean Frontier Institute, Dalhousie University, 1355 Oxford Street, P.O. Box 15000, Halifax, NS B3H 4R2, Canada
4. Institute of Marine Research, Flødevigen Marine Research Station, N-4817 His, Norway
5. Centre for Coastal Research (CCR), University of Agder, 4630Kristiansand, Norway