Lake Whitefish Production: Climate, Weather, and Ice Cover

Lake Whitefish is a native Lake Ontario forage fish that once supported a commercial fishery, but is now in severe decline. The last remaining Lake Whitefish spawning area in US waters of Lake Ontario is in Chaumont Bay. Climate conditions affect the productivity of this species; ice cover or other protections from disturbance (e.g., wave action) may play a role in this effect. We examine the hypothesis that local weather conditions, particularly the period of winter low air temperature and ice cover correlate with larval Lake Whitefish abundance the following spring. We censused Lake Whitefish larval abundance in Chaumont Bay in late April for 10 years and compared those abundances with measures of winter air temperature and ice cover. Results indicate a clear, but variable relationship between winter weather conditions and Lake Whitefish productivity. Recovery of this native prey fish would greatly benefit Lake Ontario gamefish and help restore the historic food web. However, if global climate changes increase air and water temperature, reduce the period of ice cover, or increase storm intensities, Lake Whitefish may face the threat of extirpation from Lake Ontario.