Abstract:

Following the 2010 Deepwater Horizon (DwH) catastrophe, both the immediate and chronic effects of oil pollution on salt marsh communities of the Northern Gulf of Mexico have been of intense concern. One study focusing on short-term responses (Whitehead et al. 2011. Genomic mechanisms of evolved physiological plasticity in killifish distributed along an environmental salinity gradient. PNAS, 105 (15) 6193-6193. doi:10.1073/pnas.1017542108) demonstrated a link between oil contamination and genomic and physiological responses of marsh-resident killifish (Fundulus grandis). In the present study, we target the Whitehead et al. (2010)(Whitehead et al. 2010. Comparative transcriptomics implicates mechanisms of evolved pollution tolerance in a killifish population. Molecular Ecology, 19 (23) 5186-5203. 10.1111/j.1365-294X.2010.04829.x) samples to determine if it is possible to detect a trace metal (i.e., vanadium and nickel) signature associated with the DwH oil spill in fish otoliths. Trace elements in the water column are incorporated into otoliths in daily increments. Changes in the levels of trace elements can be quantified over time using laser ablation with highly sensitive mass spectrometry. Because otoliths provide a record of the fish’s chemical environment and growth rate, the goals of the study are to first identify the time of exposure to oil and second to compare growth rates before, during, and after the exposure at oiled and not oiled sites. Additional Data Contributors/ Authors Ken Able (PI), Olaf Jensen (Co-PI) and Joel Fodrie (Co-PI).

Suggested Citation:

Lopez-Duarte, Paola, Ken Able, Olaf Jensen, and Joel Fodrie. 2014. Can Exposure to the Deepwater Horizon Oil Spill be Detected in Marsh Fish Otoliths?. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7NP22CQ

Publications:

López-Duarte, P. C., Fodrie, F. J., Jensen, O. P., Whitehead, A., Galvez, F., Dubansky, B., & Able, K. W. (2016). Is Exposure to Macondo Oil Reflected in the Otolith Chemistry of Marsh-Resident Fish? PLOS ONE, 11(9), e0162699. doi:10.1371/journal.pone.0162699

Purpose:

To assess the effects of oil exposure on Fundulus grandis (Gulf killifish) growth, fish otoliths were extracted, measured, and chemically analyzed. The first objective was to determine whether trace elements associated with oil can be detected in otoliths of fish known to have been exposed to oil. If exposure to oil can be confirmed through microchemistry, the effects on otolith growth will be assessed.

Data Parameters and Units:

Site and Raw data_OlithMicrochemistry: site, latitude, longitude, sex, old number, collection date (MM/DD/YYYY), collected by, new number, total length (mm), standard length (mm), extracted (both otoliths), pictures (whole otoliths), date cleaned (MM/DD/YYYY), resin mold, otolith prepared, distance from core to 1st cut (microns), cross section thickness (microns), core visible?, right length along Succal grove (microns), right length along Succal grove (microns), right core to ventral (microns), right core to dorsal (microns), left length along Succal grove (microns), left core to ventral (microns), left core to dorsal (microns), left cs width (after cleaning), right cs width (after cleaning), right width (perpendicular to grove), left width (perpendicular to grove), left material lost (whole width - cs width), right material lost (whole width - cs width), left % lost??, right % lost??, sectioned otolith width (right). Date folders: 2013_08 13-16 through 2013_09 9-10; xls otolith section files: resolution, time (sec), intensity (cps) Calcium (48Ca), Vanadium (51V), Manganese (55Mn), Nickel (60Ni and 62Ni), Copper (63Cu), Strontium (88Sr), Barium (138Ba), Tin (118Sn), and Lead (208Pb)

Methods:

Information regarding the individual fish (collection date, site, and lengths) from which the otoliths were collected are included in "Site and Raw data_OlithMicrochemistry". All other excel files correspond to the chemical composition of a 100x150 micron otolith section. The isotopes of ten different elements were measured: Calcium (48Ca), Vanadium (51V), Manganese (55Mn), Nickel (60Ni and 62Ni), Copper (63Cu), Strontium (88Sr), Barium (138Ba), Tin (118Sn), and Lead (208Pb). Filenames with the prefix 612 refer to the NIST 612 standard which was run along with the samples on the mass spec and are not field-collected samples.

Individual Files: