Minimal incorporation of Deepwater Horizon oil by estuarine filter feeders.
Natural abundance carbon isotope analyses are sensitive tracers for fates and use of oil in aquatic environments. Use of oil carbon in estuarine food webs should lead to isotope values approaching those of oil itself, -27‰ for stable carbon isotopes reflecting oil origins and -1000‰ for carbon-14 reflecting oil age. To test for transfer of oil from the 2010 Deepwater Horizon spill into estuarine food webs, filter-feeding barnacles (Balanus sp.) and marsh mussels (Geukensia demissa) were collected from Louisiana estuaries near the site of the oil spill. Carbon-14 analyses of these animals from open waters and oiled marshes showed that oil use was <1% and near detection limits estimated at 0.3% oil incorporation. Respiration studies showed no evidence for enhanced microbial activity in bay waters. Results are consistent with low dietary impacts of oil for filter feeders and little overall impact on respiration in the productive Louisiana estuarine systems.
Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA 70803, USA; Australian Rivers Institute, Griffith University, 170 Kessels Road, Nathan, Brisbane, Queensland 4111, Australia. Electronic address: b.fry@griffith.edu.au.
Brian
B
Fry
Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803, USA; Department of Geology and Geological Engineering and Museum of Geology, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA.
Laurie C
LC
Anderson
D000818:Animals; D049872:Bivalvia / Q000378:metabolism*; D004784:Environmental Monitoring; D008145:Louisiana; D010578:Petroleum / Q000378:metabolism*; D059392:Petroleum Pollution; D001468:Thoracica / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
D010578:Petroleum; D014874:Water Pollutants, Chemical
Barnacles; Carbon-13; Carbon-14; Deepwater Horizon; Mussels; Oil