Harbor seals (Phoca vitulina) in British Columbia, Canada, and Washington State, USA, reveal a combination of local and global polychlorinated biphenyl, dioxin, and furan signals

Abstract

The harbor seal (Phoca vitulina) can serve as a useful indicator of food web contamination by persistent organic pollutants (POPs) because of its high trophic level, wide distribution in temperate coastal waters of the Northern Hemisphere, and relative ease of capture. In 1996 through 1997, we live-captured 60 harbor seal pups from three regions, spanning remote (Queen Charlotte Strait, BC, Canada), moderately industrialized (Strait of Georgia, BC, Canada), and heavily industrialized (Puget Sound, WA, USA) marine basins straddling the Canada-United States border. Biopsy samples of blubber were taken and analyzed for congener-specific polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) by using high-resolution gas chromatography-high-resolution mass spectrometry. Harbor seals in Puget Sound were heavily contaminated with PCBs, whereas seals from the Strait of Georgia had relatively high concentrations of PCDDs and PCDFs. Pattern evaluation and principal components analysis suggested that proximity to sources influenced the mixture to which seals were exposed, with those inhabiting more remote areas being exposed to lighter PCB congeners (those with lower Henry's law constant and K(ow)) that disperse more readily through atmospheric and other processes. Total toxic equivalents to 2,3,7,8-tetrachlorodibenzo-p-dioxin for the PCBs, PCDDs, and PCDFs suggest that Puget Sound seals are at greatest risk for adverse health effects, and that PCBs represent the class of dioxinlike contaminants of greatest concern at all sites.

Bioaccumulation of polychlorinated biphenyls and organochlorine pesticides in young-of-the-year bluefish (Pomatomus saltatrix) in the vicinity of a Superfund Site in New Bedford Harbor, Massachusetts, and in the adjacent waters

“…Burse et al (1994) reported 1.33 ppm PCBs in a composite of four samples of bluefish from Clarks Cove and 0.42 ppm PCBs in a composite of three bluefish purchased in a seafood market in South Dartmouth, Massachusetts. High levels of PCBs, similar to those found in YOY bluefish from the New Bedford Harbor, have been reported in only a limited number of marine species like the blubber biopsies of bottlenose dolphins , harbor seals (Ross et al, 2004) and the Pacific orcas (Ross et al, 2000).…”

A Review of Organochlorine Contaminants in Nearshore Marine Mammal Predators

“…Dose response relationships for many of the congeners have not been well established [9]. The highest PCB values reported within marine mammals was 18,135 µg/kg within Puget Sound harbor seal (Phoca vitulina) blubber [10]. Of the cetaceans, transient Kenai Fjords/Prince William Sound killer whale blubber had the highest value of 230,000 ng/g [5].…”

Top 10 Principles for Designing Healthy Coastal Ecosystems Like the Salish Sea

“…Knowledge of food web dynamics allows managers to monitor movement of contaminants in the ecosystem (Ross et al 2004) and the effects of the toxins on species composition, abundance, diversity, and ultimately, the food web itself. Bioaccumulation of toxins has been shown to impact multiple species in many ways, from the immunologic health of harbor seals (Ross et al 1996) to the density and species richness of Phoxocephalid amphipods (Swartz et al 1982).…”