Unexpectedly high mortality in Pacific herring embryos exposed to the 2007 Cosco Busan oil spill in San Francisco Bay.

In November 2007, the container ship Cosco Busan released 54,000 gallons of bunker fuel oil into San Francisco Bay. The accident oiled shoreline near spawning habitats for the largest population of Pacific herring on the west coast of the continental United States. We assessed the health and viability of herring embryos from oiled and unoiled locations that were either deposited by natural spawning or incubated in subtidal cages. Three months after the spill, caged embryos at oiled sites showed sublethal cardiac toxicity, as expected from exposure to oil-derived polycyclic aromatic compounds (PACs). By contrast, embryos from the adjacent and shallower intertidal zone showed unexpectedly high rates of tissue necrosis and lethality unrelated to cardiotoxicity. No toxicity was observed in embryos from unoiled sites. Patterns of PACs at oiled sites were consistent with oil exposure against a background of urban sources, although tissue concentrations were lower than expected to cause lethality. Embryos sampled 2 y later from oiled sites showed modest sublethal cardiotoxicity but no elevated necrosis or mortality. Bunker oil contains the chemically uncharacterized remains of crude oil refinement, and one or more of these unidentified chemicals likely interacted with natural sunlight in the intertidal zone to kill herring embryos. This reveals an important discrepancy between the resolving power of current forensic analytical chemistry and biological responses of keystone ecological species in oiled habitats. Nevertheless, we successfully delineated the biological impacts of an oil spill in an urbanized coastal estuary with an overlapping backdrop of atmospheric, vessel, and land-based sources of PAC pollution.

Development of an enzyme-linked immunosorbent assay for quantifying vitellogenin in Pacific salmon and assessment of field exposure to environmental estrogens.

A competitive enzyme-linked immunosorbent assay was developed to quantitate vitellogenin (VTG) in plasma and serum of coho (Oncorhynchus kisutch) and chinook (O. tshawytscha) salmon. The working range of the assay was 9 to 313 ng/ml (80-20% binding), with 50% binding at 54 ng/ml. The intra-assay and interassay variations at approximately 50% binding were 8.1% (n = 9) and 9.0% (n = 9), respectively. Dilution curves of plasma or serum from coho and chinook females and estrogen-treated males were parallel to the purified coho VTG standard curve. Male plasma samples could be assayed at a minimum dilution of 1:40 (chinook) or 1:75 (coho) without assay interference because of high sample concentration, whereas minimum acceptable dilutions of male serum samples were 1:200 (chinook) or 1:600 (coho). Identification of proper techniques for preserving VTG integrity in plasma and serum samples showed that VTG from both species was robust; both sample types required no protease inhibitor despite subjection to two freeze-thaw cycles. To test its applicability, this assay was used to measure VTG in out-migrating juvenile chinook that were collected from urban and nonurban areas in Puget Sound, Washington, USA. Results showed a small but significant plasma VTG elevation at two urban sites, suggesting that these juveniles may be exposed to environmental estrogens at an early life stage. Also, wild fish tended to have higher plasma VTG levels than hatchery fish collected in the field. Elevation of mean VTG levels was similar to that previously reported in male English sole from the same area, where both males and females exhibited alterations in timing of spawning.

Polybrominated diphenyl ethers in outmigrant juvenile Chinook salmon from the lower Columbia River and Estuary and Puget Sound, Washington.

Previous studies have examined the presence, distribution, and concentrations of toxic contaminants in two major waterways in the Pacific Northwest: the lower Columbia River and Estuary (LCR&E) and Puget Sound, Washington. However, those studies have not reported on the levels of polybrominated diphenyl ethers (PBDEs) in juvenile Chinook salmon (Onchorynchus tshawytscha). Populations of Chinook salmon from the LCR&E and Puget Sound are declining, and some stocks are currently listed as "threatened" under the Endangered Species Act. Bioaccumulation of contaminants, including PBDEs, by juvenile Chinook salmon in the LCR&E and Puget Sound is of concern due to the potential toxicity of the contaminants and associated sublethal effects in fish. In this article, we present the concentrations of PBDEs measured in gutted bodies and stomach contents of outmigrant juvenile Chinook salmon collected at six sites in the LCR&E and four sites in Puget Sound. For comparison, we also analyzed gutted bodies of juvenile Chinook salmon from eight hatcheries in the LCR&E as well as samples of the hatchery fish feeds. The mean summation SigmaPBDE concentrations measured in bodies of juvenile Chinook salmon from the different sites ranged from 350 to 2800 ng/g lipid weight, whereas those in stomach contents ranged from less than the quantitation limit (<2 ng/g wet weight) to 39 ng/g wet weight. The levels of PBDEs in the hatchery fish were significantly lower than those measured in the salmon samples collected from the LCR&E and Puget Sound. These results show that outmigrant juvenile Chinook salmon in the LCR&E and Puget Sound have been exposed to PBDEs in the environment and that these chemicals are bioaccumulating in their tissues; thus, the potential effects of PBDEs on these salmon should be further investigated.

Improved flatfish health following remediation of a PAH-contaminated site in Eagle Harbor, Washington.

Eagle Harbor in Puget Sound, WA became a Superfund site in 1987 due to polycyclic aromatic hydrocarbons (PAHs) released chronically from a nearby creosoting facility. Early studies here (1983-1986) demonstrated up to an approximately 80% prevalence of toxicopathic liver lesions, including neoplasms, in resident English sole (Parophrys vetulus). These lesions in English sole are consistently associated with PAH exposure in multiple field studies, and one laboratory study. Later studies (1986-1988) incorporated biomarkers of PAH exposure and effect, including hepatic CYP1A expression and xenobiotic-DNA adducts, and biliary fluorescent aromatic compounds (FACs). Before site remediation, lesion prevalences and other biomarker values in this species from Eagle Harbor were among the highest compared to other sites in Puget Sound and the US Pacific Coast. To sequester PAH-contaminated sediments, in 1993-1994, a primary cap of clean sediment was placed over the most-contaminated 54acres, with a 15-acre secondary cap added from 2000-2002. Lesion prevalences and biomarker values before primary capping were reduced compared to 1983-1986, consistent with facility closure in 1988 and shore-based source controls begun in 1990. Liver lesion risk, hepatic CYP1A activities, and levels of biliary FACs from fish collected immediately after and at regular intervals up to 2 years after primary capping were variable relative to pre-capping. Over the entire monitoring period since primary capping (128 months), but particularly after 3 years, there was a significantly decreasing trend in biliary FACs, hepatic DNA adducts and lesion risk in English sole. In particular, lesion risk has been consistently low (<0.20) compared to primary cap initiation (set at 1.0), from approximately 4 years after primary capping through April 2004. These results show that the sediment capping process has been effective in reducing PAH exposure and associated deleterious biological effects in a resident flatfish, and that longer term monitoring of pollutant responses in biological resources, such as resident fish, is needed in order to demonstrate the efficacy of this type of remediation.

Xenoestrogen exposure and effects in English sole (Parophrys vetulus) from Puget Sound, WA.

Vitellogenin, a yolk protein produced in the liver of oviparous animals in response to estrogens, normally occurs only in sexually mature females with developing eggs. However, males can synthesize vitellogenin when exposed to environmental estrogens, making the abnormal production of vitellogenin in male animals a useful biomarker for xenoestrogen exposure. In 1997-2001, as part of the Washington State's Puget Sound Assessment and Monitoring Program, we surveyed English sole from a number of sites for evidence of xenoestrogen exposure, using vitellogenin production in males as an indicator. Significant levels of vitellogenin were found in male fish from several urban sites, with especially high numbers of fish affected in Elliott Bay, along the Seattle Waterfront. Intersex fish were rare, comprising only two fish out of more than 2900 examined. Other ovarian and testicular lesions, including oocyte atresia, were also observed, but their prevalence did not appear to be related to xenoestrogen exposure. However, at the Elliott Bay sites where abnormal vitellogenin production was observed in male sole, the timing of spawning in both male and female English sole appeared altered. Sources of xenoestrogens and types of xenoestrogens present in Elliott Bay are poorly documented, but the compounds are likely associated with industrial discharges, surface runoff, and combined sewer outfalls.

Relationships between anthropogenic chemical contaminant exposure and associated changes in reproductive parameters in male English sole (Parophrys vetulus) collected from Hylebos Waterway, Puget Sound, Washington.

Effects of chemical contaminant exposure on gonadal development in adult male English sole (Parophrys vetulus) from Hylebos Waterway and Colvos Passage, Puget Sound, Washington were investigated. Hylebos Waterway sediment is contaminated with polycyclic aromatic hydrocarbons (PAHs) and organochlorines (OCs), and Colvos Passage, a nearby nonurban area, is minimally contaminated. Fish from Hylebos Waterway had higher concentrations of both PAHs and OCs in tissues than fish from Colvos Passage. Overall, little correlation was observed between PAH exposure and biological parameters, but strong correlations were observed between OCs and the biological parameters. Migration of fish from less contaminated areas into the Hylebos Waterway during the reproductive season might have influenced these results, based on temporal changes in fish age and contaminant concentrations.