Fisheries are a vitally important renewable resource if managed sustainably (i.e., with harvest at a rate that does not deplete population levels and allows for future use). Climate change is expected to impact fish, fisheries, and the communities dependent upon them by altering fish habitat which will shift the distribution and abundance of fish populations. Changes to fish distribution and abundance will challenge current fisheries management practices and highlight the need for new adaptive approaches to manage the ecological, social, and economic impacts of climate change on fisheries. Decision-support tools can assist fishermen and fisheries managers make more informed management choices related to climate change. Using the Laurentian Great Lakes as a case-study, and specifically the Lake Whitefish (Coregonus clupeaformis) fishery in the 1836 Treaty Waters of Lakes Huron, Michigan, and Superior, the objectives of this dissertation were to: 1) Review the physical and biological mechanisms by which cold-, cool-, and warm-water fish species will be affected by climate change in the Great Lakes;2) Examine the feasibility of decision-support tools for fishery management in the context of climate change; 3) Survey Lake Whitefish fishermen, fishery researchers, and fishery managers to document need and willingness to implement a decision-support tool for harvest management of Lake Whitefish and climate change; and,4) Develop a model of Lake Whitefish recruitment including climatic relationships and project recruitment with climate change. By the end of the 21st century, the Great Lakes will be warmer, wetter, winder, with less ice cover. Changes to the Great Lakes climate will change habitat for Great Lakes fishes, including Lake Whitefish. Lake Whitefish recruitment has been linked to climate variables, specifically temperature, wind speed, and ice cover. A mechanistic model confirmed a positive relationship between Lake Whitefish recruitment and temperature and ice cover and a negative relationship between Lake Whitefish recruitment and wind speed using corrected Akaike's Information Criterion for model selection. Surveying Lake Whitefish fishermen, researchers, and managers showed that those affiliated with the fishery support the use of decision-support tools can assist this fishery integrate science into management. The survey recommendations were used to develop the decision-support tool for the Lake Whitefish climate-recruitment relationship with climate projections. Some management units will expect up to a 50% decline and others up to a 220% increase in Lake Whitefish recruitment because of spatial variability in the climate-recruitment relationships and climate projections.
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