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HISTORIC ECOLOGICAL INVESTIGATIONS OF ESTUARIES FROM NEW BEDFORD TO THE WEST BRANCH OF THE WESTPORT
Citation:
Davey, E., Roxannel Johnson, AND K. Perez. HISTORIC ECOLOGICAL INVESTIGATIONS OF ESTUARIES FROM NEW BEDFORD TO THE WEST BRANCH OF THE WESTPORT. New England Estuarine Research Society (NEERS) Fall Meeting, New Bedford, Mass, October 25 - 27, 2018.
Impact/Purpose:
The quality of estuaries can be impacted by the activities of people. Species abundance and richness are standard benthic measurements to determine potential anthropogenic impacts within estuaries. However, the ability of this information to evaluate impacts is dependent on the availability of a proper reference (i.e., clean) site. This presentation demonstrates the significance of careful reference site selection.
Description:
At least 25 years ago, US EPA was tasked to develop methods to determine ecological differences between anthropogenically impacted and pristine estuaries. We chose New Bedford Harbor (NBH), a New England estuary highly impacted by PCBs and metals. Our approach was to conduct benthic species surveys using sediment grabs within uniform grid throughout the estuary. Sediment subsamples were taken for pollutant analyses. We chose the Slocums River Estuary (SRE) as our initial reference (i.e., pristine with respect to PCBs and metals) estuary; however, there was little significant difference between the SRE and NBH using standard benthic indices. Therefore, a second reference site was selected within the West Branch of the Westport Estuary (WBWE). There were statistically significant differences between WBWE and NBH. We postulate that SRE was not as pristine as first suspected (thus a poor reference site) because of impacts from excess nutrients.