1. Institute of Biodiversity, Animal Health and Comparative Medicine University of Glasgow GlasgowG12 8QQ UK
2. Cromarty Firth Fishery Trust InvernessIV2 3HF UK
3. Department of Biology Williams College Williamstown MA01267 USA
4. Freshwater Fisheries Laboratory Marine Scotland–Science PitlochryPH16 5LB UK
5. USDA Forest Service Northern Research Station Amherst MA01003 USA
6. Université Pierre et Marie Curie Paris75005 France