Gary Sprules

Gary Sprules

Professor Emeritus


Freshwater Ecology

Professor Sprules and his students study various aspects of the structure and dynamics of aquatic food webs. Current interests center on how wind-induced movements of water masses in lakes affect trophic interactions among entrained plankton species, and the possibility that zooplankton in lakes can survive only if their prey occur in patches. Student projects include a) using drifters to track the wind-induced movement of water masses at different depths in lakes while simultaneously sampling zooplankton to test conjectures about depth-specific physical dispersal of plankton (Lauren Barth, MSc; Alex Surugiu, BSc), and b) building energy usage budgets of Daphnia under various conditions and spatial configurations of algal prey to test the hypothesis that these organisms can only meet their ration if algae occur in patches (Audrey Reid, PhD).



  • Krupika, K.L., W.G. Sprules, and A.W. Herman. 2012. The utility of body size indices derived from optical plankton counter data for the characterization of marine zooplankton assemblages. Continental Shelf Research 36: 29-40.
  • Rennie, M.D., T. Johnson, and W.G. Sprules. 2012. Energy acquisition and allocation patterns of lake whitefish (Coregonus clupeaformis) are modified when dreissenids are present. Canadian Journal of Fisheries and Aquatic Sciences 69: 41-59.
  • Foster, S.E., W.G. Sprules, and A.L. Strecker. 2012. Effects of Bythotrephes longimanus (Crustacea, Cladocera) on the abundance, morphology and prey community of Leptodora kindtii (Crustacea, Cladocera). Hydrobiologia 683: 163-172.
  • Stewart, T.J., and W.G. Sprules. 2011. Carbon-based balanced trophic structure and flows in the offshore Lake Ontario food web before (1987-1991) and after (2001-2005) invasion-induced ecosystem change. Ecological Modelling 222: 692-708.