Physical and Chemical Characterization of In-Situ Burn Residue Encountered by a Deep-Water Fishery in the Gulf of Mexico

2017-185 The response technique of in-situ burning was used to great effect during the 2010 Deepwater Horizon oil spill in the Gulf of Mexico. An estimated 220,000-310,000 bbl of surface oil was consumed by operational in-situ burn activities. Post-burn residues were not recovered, as most were denser than seawater and sank after the burns. However, late in 2010, a relatively small deep-water shrimp fishery operating on the shelf north of the Macondo wellhead encountered tarballs on or near the bottom at around 200 m. We physically and chemically characterized samples of these submerged tarballs to confirm them as originating from Deepwater Horizon burns and to understand the features that distinguish them from other residual oil types encountered during the course of the spill response. The chance intersection between a commercial fishery and residues from the in-situ burn operations suggest that the fate of in-situ burn residue should be factored into future spill response tradeoff analyses.