Consequences of large-scale salinity alteration during the Deepwater Horizon oil spill on subtidal oyster populations

Marine ecology progress series

Sean P. Powers¹  , Amelia Geggel²  , Henry Roman²  *, Jonathan H. Grabowski³  , Shahrokh Rouhani⁴  , Jacob Oehrig⁴ 

[1] Department of Marine Sciences, University of South Alabama and the Dauphin Island Sea Lab, 101 Bienville Blvd., Dauphin Island, AL 36528, USA;Industrial Economics, Inc., 2067 Massachusetts Ave., Cambridge, MA 02140, USA;Marine Science Center, Northeastern University, 430 Nahant Road, Nahant, MA 01908, USA;NewFields, Inc., 1349 W. Peachtree Street, Suite 2000, Atlanta, GA 30309, USA

关键词: Estuary;    Oil spill response;    Natural resources damage assessment;    Oyster reefs;    Gulf of Mexico;    Crassostrea virginica;    Hydrography;   

DOI  :  10.3354/meps12147

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

Response actions associated with oil spills often have significant impacts on ecological communities. During the 87 d long Deepwater Horizon oil spill, the State of Louisiana (USA) released vast quantities of Mississippi River water into 2 estuarine basins (Barataria Bay and Black Bay/Breton Sound) in response to the approach of oil. We assessed the impact on subtidal oyster populations of this novel oil spill response action using 3 independent methods: (1) comparison of fisheries-independent post-spill densities to a pre-spill temporal baseline; (2) comparison of oyster density collected during natural resource damage assessment sampling between the area of maximal freshwater impact and reference areas in the 2 basins; and (3) estimation from a dose-response model derived from an analysis of an in situ mark and recapture study conducted in 2010 to assess the relationship between salinity and oyster mortality. A substantial portion of both basins (483 km² of Barataria Bay and 362 km² of Black Bay/Breton Sound) experienced prolonged periods of very low (<5 ppt) salinity in 2010 that lasted at least 1 mo longer than the average duration of low salinity between 2006 and 2009. The 3 approaches all indicate that dramatic losses occurred in the number of market-sized (>75 mm) oysters as a result of a system-wide lowering of salinities, with an estimated 1.16 to 3.29 billion market-equivalent oysters lost. The efficacy of the large-scale response action of altering hydrographic conditions during the summer oyster growth period should be examined in light of the major perturbation to oyster communities.

【 授权许可】

Unknown