"Cisco, Coregonus artedi, have been reduced to a small fraction of their historical abundance throughout the Laurentian Great Lakes. Today, remnant spawning stocks that continue to support commercial fisheries are confined to western Lake Superior. Although these fish are of particular economic and ecologic importance in the region, formal stock assessment models have yet to be developed for the species. In addition, effects of current exploitation rates on these remnant stocks have yet to be evaluated using quantitative methods. In this thesis, we first develop and compare multiple state-of-the-art stock assessment models for a spawning stock of cisco in Thunder Bay, Ontario, in an effort to determine an appropriate assessment framework to model the remaining cisco stocks in western Lake Superior. Results strongly suggest statistical catch-at-age assessment (SCAA) methods are most appropriate for modeling cisco in Thunder Bay, and should be applied to stocks in Minnesota and Wisconsin waters of Lake Superior. We then perform a simplified management strategy evaluation of the Thunder Bay cisco stock based on the SCAA in an effort to determine both the sustainability of the current harvest control rule, and the performance of alternate harvest control rules in managing cisco in Thunder Bay. Results suggest current exploitation rates are sustainable in Thunder Bay; however, yield, long-term spawning biomass, and risk of collapse can be improved by implementing control rules involving biomass based thresholds that decrease exploitation rate at low stock sizes."--Page ii.
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