M9 AM Ecotoxicology of Reptiles
Monday, 14 November 2005: 8:00 AM - 11:40 AM in 339-340

(KEL-1117-750432) Polychlorinated biphenyl accumulation and endocrine effects in snapping turtles of the Hudson River Superfund Site.

Kelly, S¹, Rowe, C¹, Baker, J¹, Mitchelmore, C¹, Selcer, K.¹, ¹ Chesapeake Biological Laboratory, University of Maryland, Solomons, MD, USA

ABSTRACT- The upper Hudson River Superfund Site received a half-million kg of polychlorinated biphenyls (PCBs) over a 30-year period and remains one of the most heavily PCB-contaminated regions in the U.S. The common snapping turtle (Chelydra serpentina), a long-lived omnivore known to bioaccumulate persistent organic pollutants such as PCBs, is a common resident of the contaminated area. Here we present results from examinations of endocrinological correlates with PCB accumulation by adults, and maternal transfer of PCBs to offspring. Over a two-year period we collected eggs and blood samples from adult turtles in the PCB-contaminated area and in nearby, relatively pristine, areas. We analyzed extracts of whole blood samples from adult turtles and egg composites for total PCB and specific congener concentrations, as well as a limited suite of pesticides and metals. While pesticides and metals do not appear to differ significantly between the two areas, PCB concentrations were significantly elevated in tissues of animals from the contaminated area. Mean total PCB concentrations in the contaminated and reference areas, respectively, were 3840.3 ng/g ww (wet weight) and 75.9 ng/g ww (p <0.001) in eggs, and 345.3 ng/g ww and 6.77 ng/g ww (p <0.001) in adult whole blood. Concentrations of PCBs in adult blood tissue were related to sex, body mass, and proximity to contaminant point sources. As well, maternal blood PCB concentrations were correlated with PCB concentrations in their clutches. In order to assess potential PCB-mediated endocrine disruption, we measured the thyroid hormone thyroxine (T₄) and vitellogenin, an estrogen-dependent yolk precursor, in adult serum samples and correlated those data to PCB body burdens. Implications for organism- and population-level health will be discussed, specifically with regards to pending dredging activities at the Superfund site aimed at reducing exposure of resident organisms to PCBs.

Key words: PCBs, reptiles, endocrine disruption