ABSTRACT Immediately following the unprecedented use of dispersants in response to the Deepwater Horizon (a.k.a. MC252) incident, the National Response Team (NRT) issued a memorandum to NRT members and Regional Response Team (RRT) co-chairs recommending review and revision of all dispersant preauthorization plans. During this review process, the Regional Response Team 4 (RRT4) (North Carolina to Mississippi) determined that the Endangered Species Act (ESA) Section 7 consultations would likely require further revisions and that the assessment should also be prepared to request consultation in accordance with Section 305(b) of the Magnuson-Stevens Fishery Conservation and Management Act (MSA) (i.e. Essential Fish Habitat (EFH)). The RRT4 Science & Technology Committee Biological Assessment Workgroup developed a functional outline that included narrowing the focus of the assessment to evaluate only oil spill scenarios where dispersant is applied under preauthorized protocols and locations. An analysis of oil spill incidents using U.S. Coast Guard Marine Information for Safety and Law Enforcement (MISLE) data was performed to develop spill scenarios, each with dispersant response scenarios using the NOAA Dispersant Mission Planner (DMP2). The General NOAA Oil Modeling Environment (GNOME) model was used to quantitatively describe the average concentration of oil within the water column at different time steps. In close coordination with the Services, species and habitats were selected for evaluation based on their likelihood to occur in the proposed preauthorized geographic area, with effects of the action assessed for species groups. The same framework was used in preauthorization planning for in-situ burning. The summation of these steps resulted in a swift and cost-effective biological assessment process that incorporated both response tactics. Initiating or revising biological assessments and consultations to oil spill contingency plans will continue to expand beyond preauthorization for alternative countermeasures under the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) Subpart J). The RRT4 efforts contribute to the body of practical practices as national recommendations continue to be developed.
Read full abstract