GEOGRAPHICAL VARIATION OF PERSISTENT ORGANIC POLLUTANTS IN EGGS OF THREATENED LOGGERHEAD SEA TURTLES (CARETTA CARETTA) FROM SOUTHEASTERN UNITED STATES JUAN JOSE ´ ALAVA, y JENNIFER M. KELLER,*z JEANETTE WYNEKEN,§ LARRY CROWDER, k GEOFFREY SCOTT, y and JOHN R. KUCKLICKz yNational Oceanic and Atmospheric Administration, Charleston, South Carolina, USA zNational Institute of Standards and Technology, Hollings Marine Laboratory, Charleston, South Carolina, USA §Florida Atlantic University, Boca Raton, Florida, USA kDuke University Marine Laboratory, Beaufort, North Carolina, USA (Submitted 24 January 2011; Returned for Revision 11 March 2011; Accepted 4 April 2011) Abstract —Persistent organic pollutants (POPs) are recognized manmade threats to sea turtle populations, but substantial uncertainty exists surrounding their exposure to contaminants and their sensitivity to toxic effects. This uncertainty creates difficulty for conservation managers to make informed decisions for the recovery of these threatened species. To provide baseline concentrations and spatial comparisons, we measured a large suite of POPs in loggerhead sea turtle (Caretta caretta) egg yolk samples collected from 44 nests in three distinct U.S. locations: North Carolina (NC), eastern Florida (E FL), and western Florida (W FL). The POPs included polychlorinated biphenyls (PCBs), organochlorine pesticides such as dichlorodiphenyltrichloroethanes (DDTs), chlordanes, mirex, dieldin, hexachlorocyclohexanes (HCHs), hexachlorobenzene, and toxaphene congeners, as well as polybrominated diphenyl ether congeners (PBDEs). Persistent organic pollutant concentrations were lowest in W FL, intermediate in E FL, and highest in NC egg samples, with several statistically significant spatial differences. This increasing gradient along the southeast coast around the Florida peninsula to North Carolina was explained partly by the foraging site selection of the nesting females. Data from previous tracking studies show that NC nesting females feed primarily along the U.S. eastern coast, whereas W FL nesting females forage in the Gulf of Mexico and Caribbean Sea. The E FL nesting females forage in areas that overlap these two. The foraging site selection also results in exposure to different patterns of POPs. An unusual PBDE pattern was seen in the NC samples, with nearly equal contributions of PBDE congeners 47, 100, and 154. These findings are important to managers assessing threats among different stocks or subpopulations of this threatened species. Environ. Toxicol. Chem. 2011;30:1677–1688. # 2011 SETAC Keywords —Reptile Egg Lipid Contaminant Organohalogen INTRODUCTION Environmental contaminants are a recognized threat to many species, yet the uncertainty of the risk they pose to sea turtles is great, and our understanding is limited by few data [1]. Here we focus on contaminants in loggerhead sea turtle (Caretta caretta) eggs. Loggerhead sea turtles are currently listed as threatened on the U.S. Endangered Species List. However, the Northwest Atlantic subpopulation has been experiencing a long-term declining trend in nesting, which has heightened concern for the species and compelled National Marine Fisheries Service to consider this subpopulation for the more imperiled status of endangered ([2]; http://www.nmfs. noaa.gov/pr/pdfs/statusre- views/loggerheadturtle2009.pdf). Four recovery units (aggre- gations of loggerhead sea turtles, essential to the recovery of the species and delineated based partly on geographical isolation) have been identified for rookeries for the Northwest Atlantic loggerhead in the United States: the Northern nesting subpo- pulation (ranging from Virginia to northern Florida), the Pen- insular Florida subpopulation, the Northern Gulf of Mexico subpopulation, and the Dry Tortugas subpopulation [1]. The first two subpopulations were sampled in the present study. The Northern subpopulation has been declining by 1.6% per year since the 1980 s [1]; the Peninsular Florida subpopulation has experienced a cumulative decline of 28 to 31% between 1989 to 2006 [3]. The list of threats that this species faces is long, including nesting beach habitat destruction, fisheries by-catch, vessel strikes, poaching, diseases, predation, marine debris, and chemical pollutants. Baseline exposure data do not exist for contaminant con- centrations in certain sea turtle subpopulations. For example, the eastern coast of Florida hosts possibly the largest rookery of loggerheads in the world, rivaled only by Masirah in Oman [1], but only three loggerhead nests from this location have been analyzed recently for persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs) and organochlorine pes- ticides [4]. Before that study, loggerhead eggs from this region had not been collected for POP measurements since the 1970 s [5], and the analytical methods used three decades ago are now considered obsolete. Since the 1990 s, loggerhead eggs from the United States have been analyzed for POPs from only South Carolina [6], the Florida panhandle [7], and eastern Florida [4]. These three studies are similar in that they used nonlethal sampling of unhatched eggs collected after live hatchlings emerged from the nest. Despite this similarity, the data cannot be combined for a robust spatial comparison of POP exposure among the genetically distinct subpopulations or regions because of temporal differences in sampling (1970 s to 2002), differences in the suite of compounds measured, and methodological differences (e.g., Alam and Brim [7] reported on dry mass, whereas all other studies used wet mass). Environmental Toxicology and Chemistry, Vol. 30, No. 7, pp. 1677–1688, 2011 # 2011 SETAC Printed in the USA DOI: 10.1002/etc.553 * To whom correspondence may be addressed (jennifer.keller@noaa.gov). Published online 20 April 2011 in Wiley Online Library (wileyonlinelibrary.com). 1677