1. Department of Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
2. Institute of Marine Research, Nordnes, Bergen 5871, Norway
3. School of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA
4. Fisheries and Oceans Canada, Gulf Fisheries Centre, Moncton, NB E1C 9B6, Canada
5. Marine Affairs Program, Dalhousie University, Halifax, NS B3H 4R2, Canada