Working Group 15

Quantifying the effects of winter water level drawdown on the aquatic biodiversity of temperate regulated lakes

A major source of stress to aquatic biodiversity is the alteration of hydrology associated with the construction and operation of dams. Given the importance of dams on the landscape, there has been a great deal of research into the effects of hydrological modifications on river biodiversity. However, the effects of water level fluctuations on the aquatic biodiversity in regulated lakes, particularly deep (i.e. stratifying) ones, are less well understood. The studies presented in the literature to date have been fragmented, where the focus has largely been on a single population of fish or on macroinvertebrates living within a single habitat. There is a real need to synthesize the work that has been conducted to date and pair this with a comprehensive field and modeling study in order to develop a scientifically-grounded consensus on how winter water level drawdowns affect aquatic biodiversity. To tackle these needs, we have formed a working group that brings together biodiversity scientists and conservation practitioners. One of the key goals of the group is to advance our understanding of the ecological effect of winter water level drawdowns on deep regulated lakes across multiple trophic levels. Furthermore, by working collaboratively with dam operators, the group will model the effects of different management scenarios on fish.


Irene Gregory-Eaves (McGill University), Chris Solomon (McGill University), Christian Nozais (Université du Québec à Rimouski), Cosmin Vasile (CRECA), Guy Lessard (CRECA), René Charest (Sépaq),


Title Event Number of Participants Date