RIVPACS - Canada

Freshwater ecologists at CEH in the UK pioneered the RIVPACS type approach. However it has been trialled, and in some cases adopted, in many countries seeking to establish a national or regional freshwater bioassessment scheme.

Environment Canada (National Water Research Institute and Ontario Region) has developed a RIVPACS-type approach to assess freshwater sediments in the near-shore areas of the Great Lakes. A large database of reference site information was collected for the invertebrate communities associated with fine-grained sediment habitats of harbours and embayments around the lake shores. Clustering of the reference sites was done using UPGMA and following a series of intermediate steps to exclude poorly correlated environmental variables, the optimal set of predictor variables in the model was determined using MDA. The resulting model was packaged as a simple to use biomonitoring software tool (BEAST: Benthic Assessment of Sediment).

The approach also involves sediment toxicity tests, and has been used to assess community structure and sediment contamination at various Areas of Concern in the Great Lakes and other freshwater systems, such as the Fraser River in western Canada. BEAST is highly diagnostic in confirming that sediment-associated biota is being affected by adverse conditions at a site. However, as the invertebrate community integrates effects from many sources, the cause of the impairment may not be clear; therefore, toxicity tests are incorporated to provide confirmation of the relationship between contamination at a site and its effects.