Effects of streambank materials additions upon microbial activities of two sub-Arctic Canadian rivers

Abstract

In late winter the experimentally determined respiration rates of water from two sub-arctic Canadian rivers (the Swift and the Ogilvie) were found to be approximately 0.02 to 0.05 mg O 2 L -1 d -1. Additions of streambank materials to these river waters increased respiration rates as well as microbial productivities with significant influences noted over the concentration range of 0.10–10.00 g l -1 water. The time of year at which these perturbants are added is also important. These rivers would tend to be most sensitive to pipeline related construction activity which would result in streambank and sediment materials additions in winter and least sensitive in late spring (following ice “break-up”) and early summer.