T-119-15
Sport Science for Salmon and Other Species: Ecological Consequences of Metabolic Power Constraints

Benjamin Martin , Ecology, Evolution & Marine Biology, University of California Santa Barbara, Santa Barbara, CA
Roger M. Nisbet , Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, CA
Andrew Pike , Fisheries Ecology Division, NOAA Southwest Fisheries Science Center, Santa Cruz, CA
Cyril J. Michel , Fisheries Ecology Division, NOAA Southwest Fisheries Science Center, Santa Cruz, CA
Eric Danner , Fisheries Ecology Division, NOAA Southwest Fisheries Science Center, Santa Cruz, CA
For metabolically demanding behaviours, power supply (ATP resynthesis per unit time) is an important constraint on performance. Yet ecology as a discipline lacks a framework to account for these power constraints. We developed such a framework (borrowing concepts from sports science) and applied it to the upriver migration of anadromous fish. Our models demonstrate how metabolic power constraints alters optimal migratory behaviour; in response to strong counter flows, fish minimize cost of transport by alternating between rapid, anaerobically-fuelled swimming, and then holding to restore spent fuels. Models ignoring power constraints underestimated the effect of elevated water temperature on migration speed and costs (by up to 60%). These differences were primarily due to a temperature-mediated reduction in aerobic scope that impairs the ability of fish to rapidly migrate through warm waters. Our framework provides a mechanistic link between temperature-induced reductions in aerobic scope and their ecological consequences for individuals, populations, and communities.