An Assessment of the Effects of Climate Warming on Great Lakes Basin Fishes

We combine information on the influence of temperature on the physiology and ecology of fishes with information on the interrelationships between climate and physical limnology for an initial assessment of the impact of future climate warming on fishes and their habitats in the Great Lakes basin. The predicted increase in mean annual air temperature of 3.2–4.8 C° is not expected to extirpate fish taxa in the basin. Habitat warming in streams and lakes will likely shrink extant populations of salmonines and coregonines through reductions in preferred thermal habitat and allow range extensions of cyprinids, esocids, centrarchids, and ictalurids. Competition for optimal thermal space within thermal niches will increase, resulting in changes in community composition. Relatively rapid changes in water level would adversely affect the structure of wetlands and littoral areas, reducing their efficacy as spawning and nursery areas. Changes in fisheries yields of preferred species are expected.