1. Department of Biological and Environmental Science, University of Jyväskylä, FI-40014, Jyväskylä, Finland
2. Department of Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
3. Institute of Marine Research, Flødevigen Marine Research Station, His, N-4817, Norway
4. Department of Natural Sciences, University of Agder, Kristiansand, N-4604, Norway
5. Ecology Action Centre, Halifax, NS B3K 4L3, Canada