The ecology of tomtate, Haemulon aurolineatum, in the northern Gulf of Mexico and effects of the Deepwater Horizon oil spill

Tomtate, Haemulon aurolineatum, feeding ecology and growth were studied between 2009 and 2013 at natural and artificial reefs in northern Gulf of Mexico. Diet analysis (n = 747) indicated tomtate are generalist carnivores whose diet at artificial reefs was comprised of higher trophic level prey than at natural reefs. An ontogenetic shift in diet was also observed, with zooplankton predominant in the diet of juveniles, but fish and crustaceans constituting increasing percentages of diet as tomtate aged. Muscle tissue ?15N confirmed that tomtate trophic position was higher at AR versus NR sites, and that trophic position increased ontogenetically in both habitat types. Tomtate muscle ?15N, hence trophic position, increased following the Deepwater Horizon Oil Spill (DWH), and remained high until returning to pre-spill levels by the third year post-DWH. Lower ?13Cbase values in tomtate muscle post-DWH are consistent with petrocarbon, which is depleted in 13C, being a more prevalent carbon source on the nGOM shelf following the spill. Trophic effects of habitat and the DWH had important implications for tomtate growth as size at age data was greater on artificial reefs but smaller following the DWH. Slower growth following the DWH may have resulted from documented trophic shifts, or toxicological effects of the DWH have had chronic impacts on tomtate condition.