Can Exposure to the Deepwater Horizon Oil Spill be Detected in Marsh Fish Otoliths?

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).