You are here:
Applying Great Lakes coastal condition assessment (NCCA) approaches to connecting river systems: Context, compromise, and completeness
Citation:
Bolgrien, D., T. Angradi, M. Wick, M. Pawlowski, H. Sullivan, M. Nord, J. Launspach, AND E. Hinchey. Applying Great Lakes coastal condition assessment (NCCA) approaches to connecting river systems: Context, compromise, and completeness. National Water Quality Monitoring Virtual Conference, Duluth, MN, April 19 - 23, 2021. https://doi.org/10.23645/epacomptox.14428220
Impact/Purpose:
This presentation will report results of water and sediment quality surveys of the Great Lakes connecting channels. The surveys were constructed in collaboration with state and lake managers for resource-specific assessments and to create a more comprehensive assessment framework for the Great Lakes.
Description:
Environmental assessments of the lake-river systems connecting the Great Lakes have largely targeted the impacts of water level fluctuations, fisheries support, downstream nutrient delivery, and legacy contaminants. To advance the inclusion of connecting channels into routine and comprehensive Great Lakes assessments, US EPA’s Office of Research and Development and the Great Lakes National Program Office demonstrated the use of designs, methods, and assessment thresholds of the National Coastal Condition Assessment on the St. Marys River, Huron-Erie Corridor, and Niagara River. These systems were large enough that conventional limnological (rather than fluvial) methods were successfully applied. Interpreting results of the design approach and assessment thresholds proved innovative and challenging. Results from the probability-based sampling designs enable managers to contextualize the concentrations and spatial extents of water nutrients and sediment contaminants. For the Detroit River, high concentrations (relative to the spatially weighted means) of sediment contaminants are serious concerns to managers and the public even though 45% of the river’s sediment area and 83% of the corridor’s sediment area were classified as “good”. This information can help inform decisions on remediation and restoration projects and antidegradation policies. The relevancy and appropriateness of the available assessment thresholds for connecting channels remains untested and in need of more research. For example, only 15% of the area of the Huron-Erie Corridor was assessed as “good” when Lake Huron thresholds were used compared to 45% when central Lake Erie thresholds were used. For connecting channels, further research is needed to align thresholds with assessment objectives and to be at least as protective as thresholds for the downstream lake.
URLs/Downloads:
DOI: Applying Great Lakes coastal condition assessment (NCCA) approaches to connecting river systems: Context, compromise, and completeness