1. Department of Biology, Trent University, Peterborough, ON K9L0G2, Canada
2. Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON K9L 0G2, Canada
3. IISD Experimental Lakes Area Inc., Winnipeg, MB R3B0T4, Canada
4. Environmental and Resource Studies, Trent University, Peterborough, ON K9L 0G2, Canada