Role of Lake Whitefish Compensatory Mechanisms in Fisheries Sustainability

Lake whitefish Coregonus clupeaformis provide an important economic resource to both tribal and non-tribal commercial fisheries and how they respond to changing environmental conditions influences their reliability as a sustainable fishery.   Over the past century, Northern Lake Huron and Michigan have undergone extensive changes to the environment, fishing efforts, and management practices, which have directly or indirectly influenced mortality rates of lake whitefish.  One of the most substantial and well-documented changes was the invasion and proliferation of the sea lamprey Petromyzon marinus and implementation of sea lamprey control practices.  To determine how lake whitefish have historically responded to environmental changes, we are measuring the compensatory mechanisms of lake whitefish during fluctuations in mortality rates with a focus on changes in sea lamprey abundance.  Changes in lake whitefish growth, survival, and reproduction within the pre-sea lamprey, sea lamprey dominant, and current time periods will be evaluated using a life table approach.  Determining the compensatory scope of lake whitefish in Northern Lake Huron and Michigan will help managers evaluate the governance responses that will ensure the sustainability of these stocks given predicted future environmental changes such as alterations in the food web due to invasions of exotic species and climate change.