Effects of oil on the rate and trajectory of Louisiana marsh shoreline erosion

Oil can have long-term detrimental effects on marsh plant health, both above- and belowground. However, there are few data available that quantify the accelerated rate of erosion that oil may cause to marshes and the trajectory of change. Between November 2010 and August 2012, we collected data on shoreline erosion, soil strength, per cent cover of Spartina alterniflora, and marsh edge overhang at 30 closely spaced low oil and high oil sites in Bay Batiste, Louisiana. Surface oil samples were taken one meter into the marsh in February 2011. All high oiled sites in Bay Batiste were contaminated with Macondo 252 oil (oil from the Deepwater Horizon oil spill, 20 April?15 July 2010). The results suggest that there is a threshold where soil parameters change dramatically with a relatively small increase in oil concentration in the soil. Heavy oiling weakens the soil, creating a deeper undercut of the upper 50 cm of the marsh edge, and causing an accelerated rate of erosion that cascades along the shoreline. Our results demonstrate that it could take at least 2?yr to document the effects heavy oiling has had on the marsh shoreline. The presence of aboveground vegetation alone may not be an appropriate indicator of recovery.

[1]  J. Iqbal,et al.  Polycyclic Aromatic Hydrocarbons in Louisiana Rivers and Coastal Environments: Source Fingerprinting and Forensic Analysis , 2008 .

[2]  R. Delaune,et al.  Effect of crude oil on a Louisiana Spartina alterniflora salt marsh , 1979 .

[3]  Alfred C. Redfield,et al.  Development of a New England Salt Marsh , 1972 .

[4]  Harry H. Roberts,et al.  Drowning of the Mississippi Delta due to insufficient sediment supply and global sea-level rise , 2009 .

[5]  K. Fukushi,et al.  Monohydrocalcite: a promising remediation material for hazardous anions , 2011, Science and technology of advanced materials.

[6]  J. Kirchner,et al.  Effects of wet meadow riparian vegetation on streambank erosion. 2. Measurements of vegetated bank strength and consequences for failure mechanics , 2002 .

[7]  R. Schwimmer.  Rates and Processes of Marsh Shoreline Erosion in Rehoboth Bay, Delaware, U.S.A. , 2001 .

[8]  P. Montagna,et al.  Temporal and spatial patterns of anthropogenic disturbance at McMurdo Station, Antarctica , 2010 .

[9]  E. Barbier,et al.  The present and future role of coastal wetland vegetation in protecting shorelines: answering recent challenges to the paradigm , 2011 .

[10]  M. W. McCoy,et al.  Degradation and resilience in Louisiana salt marshes after the BP–Deepwater Horizon oil spill , 2012, Proceedings of the National Academy of Sciences.

[11]  G. W. Snedecor.  Statistical Methods , 1964 .

[12]  I. Mendelssohn,et al.  Impacts and recovery of the Deepwater Horizon oil spill on vegetation structure and function of coastal salt marshes in the northern Gulf of Mexico. , 2012, Environmental science & technology.

[13]  M Scott Miles,et al.  Distribution and recovery trajectory of Macondo (Mississippi Canyon 252) oil in Louisiana coastal wetlands. , 2014, Marine pollution bulletin.

[14]  J. Nyman.  Effect of Crude Oil and Chemical Additives on Metabolic Activity of Mixed Microbial Populations in Fresh Marsh Soils , 1999, Microbial Ecology.

[15]  K. Moore,et al.  EFFECTS OF THE CHESAPEAKE BAY OIL SPILL ON SALT MARSHES OF THE LOWER BAY , 1977 .

[16]  C. Gong,et al.  Modeling photosynthesis of Spartina alterniflora (smooth cordgrass) impacted by the Deepwater Horizon oil spill using Bayesian inference , 2012 .

[17]  Karin L. Lemkau,et al.  Floating oil-covered debris from Deepwater Horizon: identification and application , 2012 .

[18]  T. Wade,et al.  Linking ramped pyrolysis isotope data to oil content through PAH analysis , 2013 .

[19]  J. W. Webb,et al.  Relationship of Spartina alterniflora growth to sediment oil content following an oil spill , 1987 .

[20]  C. S. Milan,et al.  Below-ground biomass in healthy and impaired salt marshes , 2004, Ecological Research.

[21]  R. Carmichael,et al.  Oil carbon entered the coastal planktonic food web during the Deepwater Horizon oil spill , 2010 .

[22]  J. Morris,et al.  Chronic low level hydrocarbon amendments stimulate plant growth and microbial activity in salt-marsh microcosms. , 1990 .

[23]  Robert D. Brumbaugh,et al.  Quantifying the Loss of a Marine Ecosystem Service: Filtration by the Eastern Oyster in US Estuaries , 2012, Estuaries and Coasts.

[24]  Richard P. Stumpf,et al.  The process of sedimentation on the surface of a salt marsh , 1983 .

[25]  M. Torre Jorgenson,et al.  Edaphic and microclimatic controls over permafrost response to fire in interior Alaska , 2013 .

[26]  Johan van de Koppel,et al.  Self‐Organization and Vegetation Collapse in Salt Marsh Ecosystems , 2004, The American Naturalist.

[27]  S. Penland,et al.  Relative Sea-Level Rise in Louisiana and the Gulf of Mexico: 1908-1988 , 1990 .

[28]  Loren McClenachan.  Documenting Loss of Large Trophy Fish from the Florida Keys with Historical Photographs , 2009, Conservation biology : the journal of the Society for Conservation Biology.

[29]  J. W. Webb,et al.  SEASONAL RESPONSE OF SPARTINA ALTERNIFLORA TO OIL , 1985 .

[30]  Beatrice A. Stong,et al.  Shoreline Treatment during the Deepwater Horizon-Macondo Response , 2011 .

[31]  D. Qin,et al.  Storage, patterns, and control of soil organic carbon and nitrogen in the northeastern margin of the Qinghai–Tibetan Plateau , 2012 .

[32]  R. Turner,et al.  Relationships between Salt Marsh Loss and Dredged Canals in Three Louisiana Estuaries , 1997 .

[33]  S. L. Yang,et al.  Trapping Effect of Tidal Marsh Vegetation on Suspended Sediment, Yangtze Delta , 2009 .

[34]  R. Eugene Turner,et al.  Watershed land use and river engineering drive wetland formation and loss in the Mississippi River birdfoot delta , 2012 .

[35]  Linda A. Deegan,et al.  Natural factors and human modifications contributing to marsh loss in Louisiana's Mississippi River Deltaic Plain , 1984 .

[36]  I. Mendelssohn,et al.  A comparative investigation of the effects of south Louisiana crude oil on the vegetation of fresh, brackish and salt marshes , 1996 .

[37]  S. Pezeshki,et al.  The effects of oil spill and clean-up on dominant US Gulf coast marsh macrophytes: a review. , 2000, Environmental pollution.

[38]  C. Hershner,et al.  Effects of chronic oil pollution on a salt-marsh grass community , 1980 .

[39]  C. Crain,et al.  The Protective Role of Coastal Marshes: A Systematic Review and Meta-analysis , 2011, PloS one.

[40]  E. Gabet.  Lateral migration and bank erosion in a saltmarsh tidal channel in San Francisco Bay, California , 1998 .

[41]  R. Delaune,et al.  Changes occurring along a rapidly submerging coastal area: Louisiana, USA , 1986 .

[42]  R. Turner.  Beneath the Salt Marsh Canopy: Loss of Soil Strength with Increasing Nutrient Loads , 2011 .

[43]  S. Mascarella,et al.  IDENTIFICATION OF PETROLEUM RESIDUE SOURCES AFTER A FIRE AND OIL SPILL , 1981 .

[44]  K. Bjorndal,et al.  Historical Overfishing and the Recent Collapse of Coastal Ecosystems , 2001, Science.

[45]  M. Bertness,et al.  Uncertain future of New England salt marshes , 2011 .