Long-term Monitoring Improves Characterization of Reference Conditions for Assessment and Management

Session: 32. - Long-Term Monitoring: Achievements, Challenges, and Solutions

Lee Grapentine, Environment and Climate Change Canada, [email protected]

Abstract

The assessment and management of degraded sites in the Great Lakes is often a challenge because aquatic communities and their habitats can vary substantially in space and time. When reference conditions vary, benchmarks of environmental quality and the statistical power of assessments are also liable to change. Characterizing reference conditions under these conditions requires quantifying and adjusting for temporal variability. This is especially important for assessing recovery from degradation, when the restoration condition may differ from the predisturbance condition. Strategies for defining the reference conditions of benthic invertebrate communities in three disturbed nearshore areas in northern Lake Superior are described. Temporal variability of benthic communities, potentially resulting in unstable or moving benchmarks of reference conditions, was examined over 10-12 years and accommodated through the delineation of time trajectories for reference and assessment sites. This allowed not only time-specific comparisons but also indications of trends such as improvement of benthic conditions.

1. Keyword
monitoring

2. Keyword
benthos

3. Keyword
sediments

4. Additional Keyword
restoration