FOUR CASES OF SEVERED PEDUNCLES IN BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS) ALONG THE ALABAMA COAST.

Alabama (AL) is a hotspot in the Gulf of Mexico (GoM) for human interaction-related cetacean strandings, including harassment, vessel strikes, and fisheries interactions. We examined four bottlenose dolphins (Tursiops truncatus) stranded dead along the AL coast during 2012-2017 with severed peduncles suspected to be related to human interaction (HI). Evidence from each case, including photographs, gross necropsy results, and histopathologic findings when available, was reviewed to determine the mode of severance and whether it contributed to death. In each case, the severance site had smooth, clean edges on at least one side, indicating the use of a sharp instrument to remove the caudal peduncle and flukes. Three cases also had evidence of fisheries interactions, including linear impressions around the rostrum, fins and/or flukes, indicating that these animals may have been entangled in fisheries gear prior to death. Histopathology in one of these cases revealed that the severance occurred perimortem; speculatively, the caudal peduncle and flukes may have been cut off to facilitate removing the dolphin from its entanglement. Although cases of amputation and mutilation are not uncommon globally among stranding reports, few cases have been described and analyzed in the literature. This paper is the first to document and compare multiple cases of severed peduncles with evidence of HI, including fisheries, in the GoM. This case series enhances our understanding of the types of HI occurring in bottlenose dolphins and highlights the need for continued public education, policy, and management to address cases like these.

Evaluation of fatty acids and carnitine as biomarkers of PFOS exposure in biota (fish and dolphin) from Galveston Bay and the northwestern Gulf of Mexico.

Perfluorooctane sulfonate (PFOS) is a ubiquitous pollutant that elicits a wide range of toxic effects in exposed biota. Coastal zones in highly urbanized or industrial areas are particularly vulnerable to PFOS pollution. At present, information is lacking on biomarkers to assess PFOS effects on aquatic wildlife. This study investigated the efficacy of l-carnitine (or carnitine) and fatty acids as biomarkers of PFOS exposure in aquatic biota. The levels of PFOS, total and free carnitine, and 24 fatty acids (measured as fatty acid methyl esters or FAMEs) were measured in the liver, and muscle or blubber, of fish and dolphins sampled from Galveston Bay and the northern Gulf of Mexico (nGoM). Overall, bottlenose dolphins (Tursiops truncatus) had the highest hepatic PFOS levels. Galveston Bay fish, gafftopsail catfish (Bagre marinus), red drum (Sciaenops ocellatus), and spotted seatrout (Cynoscion nebulosus), had hepatic PFOS levels ∼8-13× higher than nGoM pelagic fish species, red snapper (Lutjanus campechanus) and yellowfin tuna (Thunnus albacares). The multivariate analysis of PFOS liver body-burdens and biomarkers found carnitine to be a more modal biomarker of PFOS exposure than FAMEs. Significant positive correlation of hepatic PFOS levels with total carnitine was evident for biota from Galveston Bay (fish only), and a significant correlation between PFOS and total and free carnitine was evident for biota from the nGoM (fish and dolphins). Given the essential role of carnitine in mediating fatty acid ß-oxidation, our results suggest carnitine to be a likely candidate biomarker of environmental PFOS exposure and indicative of potential dyslipidemia effects.