While chemical dispersants mitigate oil spills, they may also pose risks to coastal and estuarine ecosystems. We are determining oil and dispersant toxicity thresholds in seven key species to assess possible impacts, support recovery assessments, and provide information for making management decisions during oil spill events. We are also assessing how oil may affect the growth and virulence of Vibrio bacteria.
Why We Care
Chemical dispersants are a useful tool to mitigate oil spills, but the potential risks to sensitive estuarine species and coastal ecosystems should be carefully considered. To improve the decision making process, more information is needed on the effects of oil and oil spill dispersants on the health of coastal ecosystems.
What We Are Doing
We will determine oil and dispersant exposure thresholds for survival and sublethal responses in seven key estuarine species, representing different habitats (water column and benthos), feeding types, and trophic levels. The proposed test species include: sheepshead minnow, grass shrimp, mysids (small, shrimp-like crustaceans), an amphipod (a small, shrimp-like crustacean without a carapace), a snail, the hard shell clam, and a polychaete worm. We will also examine the influence of oil and dispersants on the growth of clinical and environmental strains of the pathogenic bacteria, Vibrio vulnificus. Additionally, we will assess the impacts these chemicals have on salt marsh vegetation (e.g., growth and survival) and benthic sediment communities, and compare these data with field data from the Deepwater Horizon oil spill to better define recovery horizons for benthic communities.
The project team includes partners from NOAA’s Office of Response and Restoration.