The fishes of the Laurentian Great Lakes have been studied and managed with various philosophies involving single species, groups of species, and ecosystems. Only recently has the emphasis shifted to a concern for biodiversity. Biodiversity has been strongly effected by habitat change, loss of indigenous species, introductions, contaminants, and changes in societal attitudes to ‘conservation’ and resource partitioning. At present there are approximately 153 established species in the lakes (not the basin). Of that total, 124 are indigenous, and 30 are naturalized. The number of species now known to have been introduced into the lakes is 57. Introductions result from authorized and unauthorized vectors. Introductions serve to indicate only one of the many impacts. In 1955 the binational Great Lakes Fishery Commission established a three‐year study entitled ‘The Role of Biodiversity in the Management of the Fishes of the Great Lakes’. The objectives of the study were the elucidation, for fishes, of the historical changes in diversity and zoogeography, food webs and ecological relationships, and human attitudes in regard to sustainability and utilization. The ultimate goal of the study was a set of recommendations to the resource managers that incorporate a concern for the maintenance of biodiversity in the goal of sustainable, consumptive and non‐consumptive, use of the resource.