Book Description
Understanding the effects of nutrients on the aquatic environment will be critical for managing industrial and municipal effluent discharges in northern Alberta rivers. One objective of this study was to identify spatial patterns of nutrient limitation in the Wapiti-Smoky and Athabasca river systems, which receive a diversity of effluent discharges including municipal sewage, agricultural runoff, and effluent from oil sands and pulp mills. Investigators conducted two experiments to accomplish this goal: identification of the interactive effects of both nutrient enrichment and grazing by aquatic insects (herbivory) on algal biomass, using nutrient diffusing substrata (NDS) downstream of the Hinton combined effluent; and using NDS to quantify large-scale patterns in algal biomass and nutrient limitation upstream and downstream of the major effluent and tributary input sources along the three rivers. NDS placed at 33 sites aided in the identification of river reaches having no nutrient limitation and those having some form of nutrient limitation.