Benthic invertebrates monitoring includes both lotic (rivers/streams) and lentic (wetlands) ecosystems. Aquatic biomonitoring provides a direct measure of change in biotic populations and communities in relation to benchmark or reference conditions and can help identify the ecological effects of cumulative stressors. Used together with the water chemical and physical monitoring components, this program uses an integrated approach to assess whether ecological affects are occurring in response to OS developments. Sampling can include the collection of invertebrates, algal biomass, water chemistry, and appropriate supporting habitat information and is conducted during periods of high abundance and diversity of macroinvertebrates. Sampling focuses on near-shore gravel and sand habitats on the Athabasca River, erosional habitats on major tributaries and in wadable areas in deltaic wetlands within the Expanded Geographical Area. As of October 2012, over 80 locations have been visited.