Impacts on Indicator Fish Species from the Reduced Flow of Power Plant Cooling Water

Anthropogenic development causes a variety of impacts on natural ecosystems, and there are many people working to understand the full extent of these impacts. This research focused on the effects that the shutdown of power plants, specifically those which draw in cooling water and release heated effluent, have on the estuarine environments they draw from. The Oyster Creek Nuclear Generating Station (OCNGS), located in Forked River, NJ, recently became the United States first nuclear generating station to shut down. In its time of operation, OCNGS drew in 5.3 billion L/day in cooling water from the Barnegat Bay estuary and released it as heated effluent (10.2 ˚C); this flow rate was reduced to five percent of its original upon shutdown.

Therefore, using long-term otter trawl data in a Before-After-Control-Impact study design, we analyzed six indicator juvenile fish species (P. americanus, P. dentatus, T. maculatus, S. fuscus, C. striata, M. menidia) that varied in both their water column occupancy and estuarine dependency level to determine their response (size or relative abundance) to the flow reduction from the OCNGS. Relative abundance did not vary for the juveniles of any indicator species, regardless of water column occupancy or estuarine dependency, in relation to the OCNGS shutdown and flow reduction. Size, seen through length frequency, varied only for one level of water column occupancy, nektonic fish, but not the other level, benthic fish. Warmer waters from the heated effluent of the OCNGS before the shutdown likely acted as a place of enhanced growth and/or refuge for nektonic species. Continued sampling of the juvenile fish within Barnegat Bay will create a higher level of confidence in results.