T-205C-2
Biomass Size Spectra As Ecological Indicators Across Broad Environmental and Anthropogenic Gradients

Tuesday, August 19, 2014: 8:40 AM
205C (Centre des congrès de Québec // Québec City Convention Centre)
Cindy Chu , Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
Nigel P. Lester , Aquatic Research and Monitoring Section, Ontario Ministry of Natural Resources, Peterborough, ON, Canada
Henrique Giacomini , Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
Brian J. Shuter , Ecology and Evolutionary Biology, Ontario Ministry of Natural Resources/University of Toronto, Toronto, ON, Canada
Donald A. Jackson , Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
Biomass size spectra (BSS) provide a means of summarizing fish community production. In lakes, abundance decreases as body size increases, that is, larger species such as Walleye are less abundant than the smaller species they forage upon such as Cisco or minnows. This relationship represents the underlying processes of energy transfer and predator-prey dynamics, which determine the abundance of taxa at different trophic levels. It approximates community production and the slope can be used to document impediments to production. This study evaluated the utility of BSS as an ecological indicator of community health and fisheries production in hundreds of lakes throughout Ontario. The relative influences of lake and watershed characteristics, community composition, climate and anthropogenic stress including exploitation on BSS were also determined. A general linear model indicated that BSS were related to lake morphometry, angler activity, climate, the presence of large predators and aquatic invasive species and water quality. Identification of regional patterns in BSS and an understanding of the factors influencing BSS will improve our ability to manage fisheries across large spatial scales.