Acute aquatic toxicity studies of Gulf of Mexico water samples collected following the Deepwater Horizon incident (May 12, 2010 to December 11, 2010)

TitleAcute aquatic toxicity studies of Gulf of Mexico water samples collected following the Deepwater Horizon incident (May 12, 2010 to December 11, 2010)
Publication TypeJournal Article
Year of Publication2015
AuthorsEchols B.S, Smith A.J, Gardinali P.R, Rand G.M
JournalChemosphere
Volume120
Pagination131-137
Date PublishedFeb
ISBN Number0045-6535
Accession NumberWOS:000348003200018
KeywordsDeepwater Horizon Oil Spill
AbstractThe potential for the Deepwater Horizon MC-252 oil incident to affect ecosystems in the Gulf of Mexico (GOM) was evaluated using Americamysis bahia, Menidia beryllina and Vibrio fischeri (Microtox (R) assay). Organisms were exposed to GOM water samples collected in May-December 2010. Samples were collected where oil was visibly present on the water surface or the presence of hydrocarbons at depth was indicated by fluorescence data or reduced dissolved oxygen. Toxicity tests were conducted using water-accommodated fractions (WAFs), and oil-in-water dispersions (OWDs). Water samples collected from May to June 2010 were used for screening tests, with OWD samples slightly more acutely toxic than WAFs. Water samples collected in July through December 2010 were subjected to definitive acute testing with both species. In A. bahia tests, total PAH concentrations for OWD exposures ranged from non-detect to 23.0 mu g L-1, while WAF exposures ranged from non-detect to 1.88 mu g L-1. Mortality was >20% in five OWD exposures with A. bahia and three of the WAF definitive tests. Total PAH concentrations were lower for M. belyllina tests, ranging from non-detect to 0.64 mu g L-1 and non-detect to 0.17 mu g L-1 for OWD and WAF exposures, respectively. Only tests from two water samples in both the WAFs and OWDs exhibited >20% mortality to M. beryllina. Microtox (R) assays showed stimulatory and inhibitory responses with no relationship with PAH exposure concentrations. Most mortality in A. bahia and M. beryllina occurred in water samples collected before the well was capped in July 2010 with a clear decline in mortality associated with a decline in total PAH water concentrations. (C) 2014 Elsevier Ltd. All rights reserved.
DOI10.1016/j.chemosphere.2014.06.048