title: Oil spill dispersants induce formation of marine snow by phytoplankton-associated bacteria.
abstract: Unusually large amounts of marine snow, including Extracellular Polymeric Substances (EPS), were formed during the 2010 Deepwater Horizon oil spill. The marine snow settled with oil and clay minerals as an oily sludge layer on the deep sea floor. This study tested the hypothesis that the unprecedented amount of chemical dispersants applied during high phytoplankton densities in the Gulf of Mexico induced high EPS formation. Two marine phytoplankton species (Dunaliella tertiolecta and Phaeodactylum tricornutum) produced EPS within days when exposed to the dispersant Corexit 9500. Phytoplankton-associated bacteria were shown to be responsible for the formation. The EPS consisted of proteins and to lesser extent polysaccharides. This study reveals an unexpected consequence of the presence of phytoplankton. This emphasizes the need to test the action of dispersants under realistic field conditions, which may seriously alter the fate of oil in the environment via increased marine snow formation.
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA, Wageningen, The Netherlands. Electronic address: Justine.vaneenennaam@wur.nl.
authors.forename: Justine S
authors.initials: JS
authors.lastname: van Eenennaam
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA, Wageningen, The Netherlands.
authors.forename: Yuzhu
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA, Wageningen, The Netherlands.
authors.forename: Katja C F
authors.initials: KC
authors.lastname: Grolle
authors.affiliation: IMARES, Wageningen UR, P.O. Box 57, 1780 AB, Den Helder, The Netherlands.
authors.forename: Edwin M
authors.initials: EM
authors.lastname: Foekema
authors.affiliation: Marine Animal Ecology Group, Wageningen University, P.O. Box 338, 6700 AH, Wageningen, The Netherlands.
authors.forename: AlberTinka J
authors.initials: AJ
authors.lastname: Murk
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D004784:Environmental Monitoring; D008055:Lipids; D008800:Mexico; D059392:Petroleum Pollution; D010839:Phytoplankton / Q000378:metabolism*; D013501:Surface-Active Agents / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D008055:Lipids; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; C470995:corexit 9500
keywords: Deepwater horizon; Dispersants; Extracellular polymeric substances; Marine phytoplankton; Marine snow; Symbiotic bacteria