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Oil spill chemical response agent toxicity to freshwater and estuarine species
Citation:
Moso, E., A. Bejarano, R. Conmy, P. Meyer, D. Sundaravadivelu, AND M. Barron. Oil spill chemical response agent toxicity to freshwater and estuarine species. SERC SETAC, Pensacola, FL, September 12 - 14, 2019.
Impact/Purpose:
The purpose of this invited presentation is to summarize EPA's new oil spill agent ecotoxicology research at the Southeast Regional Chapter meeting of SETAC in Pensacola, FL. The research is impactful because it provides new toxicity data needed for judging the relative hazards of spill response agents. The presentation is impactful because the Chapter meeting will be attended by and presentation will be heard by a diversity of scientists from the Southeast U.S, providing a regional forum for communicating EPA science. Participation at the meeting will provide an important career development opportunity by attending other presentations and interacting with other scientists.
Description:
Oil spill chemical response agents, including those that function as dispersants, solidifiers, surface washers, and surface collectors, are used globally to combat oil spills by changing the physical structure of the oil in the spill to facilitate breakdown and biodegradation. A well-known example is the 2010 Deepwater Horizon oil spill, which used nearly two million gallons of Corexit dispersants to break petroleum oil into small droplets that can more easily mix with water and disperse under the ocean surface. Previous studies assessing potential hazards of these chemical response agents have largely focused on effects observed in two standard estuarine test species: mysid shrimp (Americamysis bahia) and inland silverside fish (Menidia beryllina). However, this study examined acute toxicity of six chemical response agents with different functions across four taxa from freshwater and estuarine environments. The dispersant agents Corexit, Finasol, and Accell were tested on mysid and inland silversides. The agents Cytosol (a surface washer), Gelco (a solidifier), and Siltech (a surface collector), were tested on the freshwater branchiopod crustacean (Ceriodaphnia dubia) and fathead minnow fish (Pimephales promelas), in addition to the estuarine mysid and inland silverside. Consistent with the other studies, including listings on the U.S. National Contingency Plan Product Schedule, general rank order toxicity to mysids and silversides was greatest for surface collectors and dispersants, and lowest for the solidifier and surface washer agent. The surface washer, solidifier, and surface collector agents each had generally similar acute toxicity in the two freshwater species as estuarine species. Increasing our understanding of species sensitivities to chemical response agents to encompass freshwater taxa is a valuable addition to testing programs because crude oil may be transported to refineries by pipeline, rail, barge, or tankers and spills from these sources have the potential to impact freshwater environments.