DDT in endangered Galapagos sea lions (Zalophus wollebaeki)

Production of Persistent Organic Pollutants from Cement Plants

“…When in contact with water they also will be transported to planktonic organisms, entering the food chain. POPs were found as contaminants in birds (Chen and Hale, 2010;Vorkamp et al, 2009), penguins (Corsoloni et al, 20060, fish (Ondarza et al, 2011;Hardell et al, 2010), sea lions (Alava et al, 2011), among others.…”

DDT Strikes Back: Galapagos Sea Lions Face Increasing Health Risks

“…To start documenting the response of tropical wildlife to an increased use in DDT, we measured DDT concentrations in blubber biopsy samples collected from endemic and endangered Galapagos sea lion pups (Zalophus wolleabeki; Fig. 2) of the Galapagos Islands, located at 1,000 km offshore from continental Ecuador, in 2005 (n = 21 pups) before the 2006 WHO recommendation and in 2008 (n = 20 pups) after the WHO recommendation ; we also conducted a risk assessment of the health impacts of DDT concentrations and its main metabolite p,p 0 -DDE by comparing the detected concentrations in pups against toxic effect reference values documented in the literature as documented elsewhere (Alava 2011;Alava et al 2011). DDT mean ± (SE) concentrations in samples collected in 2008 (530 ± 110 lg kg -1 lipid) were significantly greater than concentrations (280 ± 150 lg kg -1 lipid), measured in 2005 (t test = 3.465, P = 0.0013), indicating a plausible increase of 86% in DDT levels .…”

“…Synergetic and/or additive toxic effects due to mixtures with other pollutants with similar mode of toxicity can contribute to impacts on the immune and endocrine systems as concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ether (PBDEs) flame retardants were also recently detected in these animals ). POPs can bioaccumulate in oceanic and coastalmarine food chains of the Galapagos sea lion, compromising its heath and reproductive status (Alava et al 2010;Alava 2011;Alava et al 2011). A compromised immune and endocrine system affects the ability of animals to combat disease and to successfully reproduce, which is especially relevant during periods of nutritional and other types of stress in stochastic environments (e.g.…”

Assessing Biomagnification and Trophic Transport of Persistent Organic Pollutants in the Food Chain of the Galapagos Sea Lion (Zalophus wollebaeki): Conservation and Management Implications

“…The Galapagos sea lion has been recognized as a key species for the functioning and health of the marine ecosystem of the islands under the environmental management action plan of the Galapagos Marine Reserve (GMR) [33]. Because of its high trophic position, relative abundance in the islands and non-migratory behaviour, Galapagos sea lions can serve as local sentinels of food web contamination [33][34][35]. Concentrations of polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT) were recently detected in this species, underlying the health risk due to the toxicity and bioaccumulation potential of these contaminants in the Galapagos food web [34,35].…”

“…Because of its high trophic position, relative abundance in the islands and non-migratory behaviour, Galapagos sea lions can serve as local sentinels of food web contamination [33][34][35]. Concentrations of polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT) were recently detected in this species, underlying the health risk due to the toxicity and bioaccumulation potential of these contaminants in the Galapagos food web [34,35]. Thus, equivalent to the role of killer whales as global sentinels of pollution in the Northeastern Pacific [1], the Galapagos sea lion can be used as an eco-marker of environmental pollution and a key indicator of not only the coastal marine health, but the public health in the region.…”