Developing a Nationally Consistent Approach for Assessing Regional Associations between Nutrients and Benthic Biological Condition in Estuarine Waters
Eric Weissberger 1, Janet Nestlerode 2, Anita Morzillo 3, Jeff Hollister 2 and John Paul 4
1 U.S. Environmental Protection Agency Office of Research and Development, National Health and Environmental Effects Laboratory, Atlantic Ecology Division, Narragansett, Rhode Island
2 USEPA/ORD/NHEERL, Gulf Ecology Division, Gulf Breeze, Florida
3 USEPA/ORD/NHEERL, Western Ecology Division, Corvallis, Oregon
4 USEPA/ORD/NHEERL, Research Triangle Park, North Carolina
Identifying candidate water quality criteria in estuarine waters is confounded by differences among estuaries and biogeographic regions. Addressing these differences is paramount to assess estuarine water quality impairment successfully. We outline an approach to investigate relationships between water column nutrient concentrations and the condition of estuarine benthic communities to identify candidate water quality criteria in estuarine waters. Using data from the National Coastal Assessment, a nationally-consistent, probability-based estuarine monitoring program, and statistical techniques used to develop the USEPA’s Suspended and Bedded Sediments (SABS) water quality criteria, we are addressing the following questions across estuary, biogeographic region, and national levels:
- Are particular nutrient variables associated with benthic condition?
- Are these explanatory variables consistent across biogeographic regions?
- How can associations from regional to national levels be used to develop the setting of locally specific estuarine benthic biological criteria?
- Because benthic condition indices vary across biogeographic regions, is it possible to use a consistent approach to develop a nationally consistent and biologically relevant measure of benthic biological condition?
These associations from regional to national levels can be used to inform the USEPA Office of Water during the process of developing national nutrient criteria for estuaries and to intercalibrate estuarine benthic condition indices across the nation.
Keywords: nutrients, benthic condition index, estuaries, landscape ecology, water quality, benthic-pelagic coupling, biological indicators