Extent and Degree of Shoreline Oiling: Deepwater Horizon Oil Spill, Gulf of Mexico, USA

Abstract

The oil from the 2010 Deepwater Horizon spill in the Gulf of Mexico was documented by shoreline assessment teams as stranding on 1,773 km of shoreline. Beaches comprised 50.8%, marshes 44.9%, and other shoreline types 4.3% of the oiled shoreline. Shoreline cleanup activities were authorized on 660 km, or 73.3% of oiled beaches and up to 71 km, or 8.9% of oiled marshes and associated habitats. One year after the spill began, oil remained on 847 km; two years later, oil remained on 687 km, though at much lesser degrees of oiling. For example, shorelines characterized as heavily oiled went from a maximum of 360 km, to 22.4 km one year later, and to 6.4 km two years later. Shoreline cleanup has been conducted to meet habitat-specific cleanup endpoints and will continue until all oiled shoreline segments meet endpoints. The entire shoreline cleanup program has been managed under the Shoreline Cleanup Assessment Technique (SCAT) Program, which is a systematic, objective, and inclusive process to collect data on shoreline oiling conditions and support decision making on appropriate cleanup methods and endpoints. It was a particularly valuable and effective process during such a complex spill.

Microbial community successional patterns in beach sands impacted by the Deepwater Horizon oil spill

“…The Unified Area Command estimated that approximately one-half of the B4.9 million barrels of oil released from the DWH blowout reached the ocean surface (Lubchenco et al, 2010), and a portion of this surfaced oil transported to nearshore and coastal ecosystems was buried in the sediments (Hayworth et al, 2011;Wang and Roberts, 2013), impacting approximately 850 km of beaches from east Texas to west Florida (Michel et al, 2013). Oil started depositing on the Pensacola Beach sands studied here on 22 June 2010.…”

Marsh Loss Due to Cumulative Impacts of Hurricane Isaac and the Deepwater Horizon Oil Spill in Louisiana

“…We did not have data on the kind of treatment performed at each site, but we did have access to information on whether a site was treated or not [63]. We hypothesized that oiled sites that were treated would likely show better recovery in 2011 and less land loss in 2012 as a result of the hurricane.…”

“…The post-oil management actions were geared towards salt marsh recovery and included marsh cleanup actions. Most of the marsh oiling occurred in Louisiana (94.8%), and treatment was customized to specific shoreline segments (71 km out of 796 km of affected marshes) [63]. Cleanup activities were terminated when there was no visible flushable oil, no release of sheens and no thick oil (>1 cm) was detected on the marsh.…”

“…Cleanup activities were terminated when there was no visible flushable oil, no release of sheens and no thick oil (>1 cm) was detected on the marsh. Natural attenuation was often recommended to avoid further damage to the marshes [63]. We tested whether untreated oiled sites showed greater land loss and vegetation stress relative to treated oiled sites by comparing indices using the Kruskal-Wallis test and land cover and change metrics using the GLM test as described in Section 2.4.…”

The effects of N, P and crude oil on the decomposition of Spartina alterniflora belowground biomass

“…There are multiple potential chronic stressors, including those arising from alterations in the hydrologic regime, sea level rise, and the top-down effects of food web alterations (e.g., Silliman et al 2009). A dramatic recent exposure to stress was from the 2010 BP Macondo oil disaster (aka Deepwater Horizon; DWH) in the Gulf of Mexico, which resulted in 1773 km of shoreline oiling, decreases in soil strength below 50 cm, and increased shoreline erosion (Michel et al 2013;McClenachan et al 2013). There were shoreline marshes that subsided in situ soon after the spill, and others that eroded at the edge (Fig.…”