Polychlorinated Biphenyls and Polybrominated Diphenyl Ethers in Galapagos Sea Lions (Zalophus wollebaeki)

Abstract

Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) were measured in muscle-blubber biopsy samples from 21 Galapagos sea lion (Zalophus wollebaeki) pups that were live captured in the Galapagos Islands (Ecuador) using gas chromatography/high-resolution mass spectrometry. Only traces of PBDEs were detected in one male pup, whereas PCDDs and PCDFs were not detected in any sample. The total concentration of PCBs (ΣPCB) in the pups averaged 104 μg/kg lipid (range, 49-384 μg/kg). No statistically significant differences in ΣPCB were observed among the four study sites in the Galapagos Islands. Concentrations of PCB congeners in Galapagos sea lion pups were dominated by low-molecular-weight congeners. These results suggest that global transport is the main source for PCBs in Galapagos sea lions. The ΣPCB levels were below immunotoxic and endocrine-disruption thresholds in pinnipeds, suggesting a limited risk of adverse health effects. The present study indicates that Galapagos sea lions can serve as a useful sentinel of pollutants with a long-range transport capacity and that Galapagos Islands are not exempt from the threats of global pollutants despite its remote locale.

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 specific methodology and protocols for the quantification and analytical methods to determine PCB congeners and OCPs have previously been reported in prior published papers (34,35).…”

“…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.…”

DDT Strikes Back: Galapagos Sea Lions Face Increasing Health Risks

“…2 The Galapagos sea lion is an endemic marine mammal to the Galapagos Islands and an endangered pinniped species, which have declined from 40,000 to 16,000 animals since the late 1970s (Picture: J.J. Alava) Alava et al 2009). While additional temporal monitoring of DDT levels in Galapagos sea lions will provide greater insight into environmental responses to recent DDT use, our study provides a timely warning signal of the dangers of an increased reliance of DDT for malaria control in tropical countries.…”

Influence of Habitat Pollution on Organophosphate Esters and Polycyclic Aromatic Hydrocarbons in Cicadas

“…For recent studies, Johnson-Restrepo et al (2008) identified tetrabromobisphenol A and hexabromocyclododecanes in tissues of humans, dolphins, and sharks. Alava J. J. et al (2009) reported pollutants, such as polychlorinated biphenyls and polybrominated diphenyl ethers in Galapagos sea lions. In relation to the current state, the bioaccumulation regulations including the bioconcentration factor (BCF) and bioaccumulation factor (BAF) have been introduced in the United States, Canada, and Europe.…”