Prediction and assessment of potential effects of global environmental change on freshwater sport fish habitat in British Columbia

The high topographic relief and physiographic diversity of British Columbia make it a particularly difficult region in which to consider the potential of global environmental change to affect lake and stream habitats important for freshwater sportfish production. More importantly these provincial features intensify problems in predicting the magnitude and sometimes even the direction of such effects. Nevertheless a number of useful models are available to help predict these changes acting through alterations in stream discharge and periodicity, ice-free period, water temperature, epilimnial depth and volume, dissolved oxygen level and hypolomnetic depletion rate, all of which are major determinants of sportfish habitat quality and quantity. Not surprisingly there is great regional difference in the direction and severity of probable effects of global environmental change within the province — in some areas negative and in others positive. These are reviewed and suggestions made regarding management policies required to meet their challenge.