Large‐scale environmental impacts, such as those of climate change on fisheries, require policy and management action not only at the local level, but at regional, national and international levels. Fisheries biology and ecology, along with social, political and economic considerations, can influence policy design and implementation. Decision‐support tools can integrate these sciences to distil often complex, mechanistic and synergistic processes into a format that the public, policy makers and managers can use when designing strategies to ensure fisheries sustainability in the face of large‐scale environmental perturbations, such as climate change. Harvest management of lake whitefish, Coregonus clupeaformis (Mitchill), in the Laurentian Great Lakes provides an excellent case study to examine the value and utility of a decision‐support tool for inland fisheries management when considering the effects of climate change because this fishery is expected to be impacted by future changes in water temperature, ice cover and wind speed.