Investigation of Petroleum and Wastewater Contaminants in Blue Crab, Callinectes sapidus, Megalopae in the Northern Gulf of Mexico using GC-MS

We collected blue crab, Callinectes sapidus, megalopae five days per week over a six-month period in 2010 and 2011 at multiple sites across the Northern Gulf of Mexico, and one site in 2013. We used GC-MS to investigate if we could detect evidence of petroleum hydrocarbons in megalopae, and if detected hydrocarbons could be linked to the DWH oil spill. We made a comparison between the distance from the oil slick to our collection sites and the concentration of long straight chain alkanes found in megalopae. We also compared levels of alkanes in megalopae between years. We then scanned the megalopae for presence of other contaminants using GC-MS.

We detected long straight chain alkanes in megalopae in 2010 but not in 2011 or 2013. The highest levels of alkanes were found in Grand Isle, suggesting that the alkanes could possibly be sourced from the DWH oil spill. No Polycyclic Aromatic Hydrocarbons (PAHs) were detected, and we found no significant relationship between distance of oil slick to collection sites. Other componds were also detected, of which 4-nonylphenol, butylated hydroxytoluene, 2,4,6-tri-tertbutylphenol, and 2,4-di-tertbutylphenol exceeded the quantification limit.