State of Science of Dispersants and Dispersed Oil in U.S. Arctic Waters

Use of dispersants was very limited in the U.S. prior to the Deepwater Horizon (DWH) oil spill in 2010. For that spill, the volume of dispersants applied, as well as the sub sea injection, was unprecedented. It has been suggested that dispersants could be a response option to a large oil spill in the Arctic, particularly because of the remoteness and harsh environmental conditions. One of the outcomes of a 2014 Arctic oil spill drill for senior U.S. agency leadership identified the need for a definitive evaluation of the state-of-science of dispersants and dispersed oil (DDO), particularly as it applies to Arctic waters. For the purposes of this evaluation, the U.S. Arctic is defined as including the Bering Sea and waters as far south as the Aleutian Islands. The Coastal Response Research Center (CRRC) convened five panels of governmental, academic, NGO, and private sector experts to determine the state of DDO science, specifically the knowns and uncertainties. The panels focused on the following five topics: Efficacy and Effectiveness, Physical Transport and Chemical Behavior; Degradation and Fate; Public Health and Food Security; and Eco-Toxicity and Sublethal Impacts. Activities conducted by the CRRC included: collating and constructing a database of the existing scientific literature, and facilitating the discussions of each panel of scientists over a period of 1.5 years. Once each panel had formulated its document regarding the state-of-science (i.e., knowns and uncertainties) regarding DDO, particularly as it applies to Arctic waters, the CRRC requested written input from the public on what to add, remove or change about these statements. Finally, each panel reviewed the public input and decided upon its final statements of knowns and uncertainties. This paper will present a summary of the statements and their implications for the use of dispersants in oil spill response in U.S. Arctic waters.