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**The title, authors, and abstract for this completion report are provided below. For a copy of the completion report, please contact the GLFC via e-mail or via telephone at 734-662-3209** The Applicability of Life History Invariants in the Great Lakes Marten A. Koops1 and Cindy Chu2
1 Great Lakes Laboratory for Fisheries and Aquatic Sciences Fisheries and Oceans Canada 867 Lakeshore Road Burlington, ON, L7R 4A6 Canada p: 905-336-4559 f: 905-336-64327 e: KoopsM@dfo-mpo.gc.ca 2 Watershed Ecosystem Graduate Program Trent University 1600 West Burbank Drive, P.O. Box 4840 Peterborough, ON, K9J 8N8 e: CindyChu@trentu.ca Abstract: Life history invariants are symmetries in the trade-offs among life history traits, representing optimality ridges where a change in one life history trait produces a constant, predictable change in another life history trait. Life history invariants generally involve growth, maturity and mortality parameters. They are attractive for their utility in predicting the values of life history traits for which data are lacking or difficult to acquire. Excellent fits of proposed life history invariants to large amounts of interspecific data has encouraged the use of proposed invariants in both management and modelling. However, the few published intraspecific comparisons have been inconsistent in their support of proposed invariants. To test the applicability of life history invariants to fishes within the Great Lakes, we compiled data on the life histories of lake trout (Salvelinus namaycush), lake whitefish (Coregonus clupeaformis), bloater (Coregonus hoyi), walleye (Sander vitreus), and yellow perch (Perca flavescens) across the Great Lakes. Support for the proposed life history invariants varied among species, across populations, and between years. The data most consistently supported the 1 st Beverton-Holt (M/k = 1.5) and the Jensen (αk = ln3) invariants, however, caution should be used when applying life history invariants to modelling exercises and fisheries management. |