Response of nearshore ecosystems to the Deepwater Horizon oil spill

Abstract

Nearshore coastal ecosystems are among the most productive environments on the planet but are threatened as a result of sea level rise, human development and pollution. These ecosystems often act as a sink for contaminants released into the open ocean as documented during the 2010 Deepwater Horizon oil spill. The geographic extent (1000s of km of potentially impacted beaches and marshes) and duration (87 d of oil release) of this oil spill as well as the related response and clean-up activities were unprecedented. Six years after the spill, studies supported by the Deepwater Horizon Natural Resources Damage Assessment as well as other independent investigations have elucidated many of the consequences of one of the world's largest oil spills. Understanding these impacts required the integration of multiple marine disciplines (e.g. physical oceanography, zoology, botany, toxicology, geospatial analysis and modeling). The contributions to this Theme Section highlight 4 key findings that are critical in assessing and responding to future oil spills: (1) organismal level effects were documented across the full range of trophic levels in areas that experienced heavy oiling; (2) degradation or loss of habitat-forming species represents a pathway to long-term direct and indirect effects; (3) the loss and degradation of these habitats result in a wide range of ecosystem service losses; and (4) response actions designed to mitigate the effects of oil often result in ecological injury. Assessment of future oil spill damages should adopt a conceptual model of injury pathways early in the impact assessment process, and this model should focus heavily on habitat-forming species.