Predatory bird species occupy high trophic levels and consequently are susceptible to bioaccumulating high levels of environmental contaminants. To evaluate potential risks from exposure to past- and current- use contaminants, levels of legacy contaminants and contaminants of emerging concern were measured in livers of 26 birds of prey from coastal South Carolina, USA. The birds included in the study spanned 10 species. As determined by stable isotope analysis, the individuals in the study spanned 2 to 3 trophic levels, exhibited a wide range of body conditions and utilized a diversity of habitats, which allowed for a detailed assessment of the factors that influence contaminant exposure. Legacy contaminant levels in the birds-of-prey were highly variable, but generally comparable to levels reported previously for the southeast U.S. region, suggesting that exposure has not declined substantially over the past 40 years. Despite their status as newly-emerging environmental contaminants, PFC levels were within the same order of magnitude as legacy contaminants. Although PBDEs were less prevalent, the levels detected in SC birds of prey were among the highest observed in wildlife to date (∑PBDEs max. 200 µg/g lipid); such high level of exposure prompts concern. Body condition was the most significant determinant of contaminant exposure, suggesting that as body condition (i.e. muscle reserves) declines contaminant levels increase within target tissues, potentially heightening risk of exposurerelated effects. The relationships between contaminant exposure and other factors, such as trophic level or proximity to large human populations, were just outside the bounds of significance, suggesting a larger sample size and additional biological data are needed to substantiate these preliminary observations. In summary, this study demonstrates that birds-of-prey in the coastal SC region continue to face exposure to legacy contaminants as well as newly-emerging contaminants.
Citation: Journal of Wildlife Diseases
Pub Type: Journals
birds-of-prey, contaminants, liver, organohalogens, PBDEs, PCBs, PFCs