Impacts of Macondo oil from Deepwater Horizon spill on the growth response of the common reed Phragmites australis: a mesocosm study.
We investigated impacts of Macondo MC252 oil from the Deepwater Horizon (DWH) spill on the common reed Phragmites australis (Cav.) Trin. ex Steud., a dominant species of the Mississippi River Delta. In greenhouse experiments, we simulated the most common DWH oiling scenarios by applying weathered and emulsified Macondo oil to aboveground shoots at varying degrees of coverage (0-100%) or directly to marsh soil at different dosages (0-16 Lm(-)(2)). P. australis exhibited strong resistance to negative impacts when oil was applied to shoots alone, while reductions in above- and belowground plant growth were apparent when oil was applied to the soil or with repeated shoot-oiling. Although soil-oiling compromised plant function, mortality of P. australis did not occur. Our results demonstrate that P. australis has a high tolerance to weathered and emulsified Macondo oil, and that mode of exposure (aboveground versus belowground) was a primary determinant of impact severity.
Department of Environmental Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
Chad R
CR
Judy
Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
Sean A
SA
Graham
Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
Qianxin
Q
Lin
Department of Environmental Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
Aixin
A
Hou
Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA 70803, USA. Electronic address: imendel@lsu.edu.
Irving A
IA
Mendelssohn
D010578:Petroleum / Q000633:toxicity*; D059392:Petroleum Pollution; D063245:Plant Development / Q000187:drug effects; D006109:Poaceae / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D053833:Wetlands
D010578:Petroleum; D014874:Water Pollutants, Chemical
Deepwater Horizon; Growth response; Macondo oil; Oil spill; Phragmites australis