Validation of a fish habitat model for lakes

Water temperatures and dissolved oxygen concentrations in 27 classes of lakes have been hindcast by simulation models and related to presence of coldwater, coolwater, and warmwater fishes in 3002 Minnesota lakes. A one-dimensional, dynamic water quality model driven by 25 years of daily weather data was used to model water temperature and dissolved oxygen profiles of these lakes. Fish presence data were available for these lakes from the Minnesota Lake Fisheries Data Base. Water temperature and dissolved oxygen criteria derived from a very large United States Environmental Protection Agency fish-temperature database and dissolved oxygen observations were used to define and link simulated water temperatures and dissolved oxygen conditions to suitability of habitats for coldwater, coolwater, and warmwater fish assemblages. Good agreement was found between fish presence and numerical simulations of fish habitat defined by water temperatures and dissolved oxygen concentrations. Generally water temperature and DO are good indicators of suitable fish habitat.