Dietary Exposure to Environmentally Relevant Levels of Chemical Contaminants Reduces Growth and Survival in Juvenile Chinook Salmon.

Chemical pollution can degrade aquatic ecosystems. Chinook salmon in contaminated habitats are vulnerable to health impacts from toxic exposures. Few studies have been conducted on adverse health outcomes associated with current levels and mixtures of contaminants. Fewer still address effects specific to the juvenile life-stage of salmonids. The present study evaluated contaminant-related effects from dietary exposure to environmentally relevant concentrations and mixture profiles in juvenile Chinook salmon from industrialized waterways in the U.S. Pacific Northwest using two end points: growth assessment and disease susceptibility. The dose and chemical proportions were reconstituted based on environmental sampling and analysis using the stomach contents of juvenile Chinook salmon recently collected from contaminated, industrialized waterways. Groups of fish were fed a mixture with fixed proportions of 10 polychlorinated biphenyls (PCBs), 3 dichlorodiphenyltrichloroethanes (DDTs), and 13 polycyclic aromatic hydrocarbons (PAHs) at five concentrations for 35 days. These contaminant compounds were selected because of elevated concentrations and the widespread presence in sediments throughout industrialized waterways. Fork length and otolith microstructural growth indicators were significantly reduced in fish fed environmentally relevant concentrations of these contaminants. In addition, contaminant-exposed Chinook salmon were more susceptible to disease during controlled challenges with the pathogen Aeromonas salmonicida. Our results indicate that dietary exposure to contaminants impairs growth and immune function in juvenile Chinook salmon, thereby highlighting that current environmental exposure to chemicals of potential management concern threatens the viability of exposed salmon.

Influence of Life-History Parameters on Persistent Organic Pollutant Concentrations in Blubber of Eastern North Pacific Gray Whales (Eschrichtius robustus).

Exposure to persistent organic pollutants (POPs) can significantly impact marine mammal health, reproduction, and fitness. This study addresses a significant 20-year gap in gray whale contaminant monitoring through analysis of POPs in 120 blubber biopsies. The scope of this substantial sample set is noteworthy in its range and diversity with collection between 2003 and 2017 along North America's west coast and across diverse sex, age, and reproductive parameters, including paired mothers and calves. Mean blubber concentrations of polychlorinated biphenyls (∑PCBs), dichlorodiphenyltrichloroethanes (∑DDTs), and chlordanes (∑CHLs) generally decreased since previous reports (1968-1999). This is the first report of polybrominated diphenyl ethers (PBDEs) and select hexachlorocyclohexanes (HCHs) in this species. Statistical modeling of the 19 most frequently detected compounds in this dataset revealed sex-, age-, and reproductive status-related patterns, predominantly attributed to maternal offloading. Mean POP concentrations differed significantly by sex in adults (17 compounds, up to 3-fold higher in males) but not in immatures (all 19 compounds). Mean POP concentrations were significantly greater in adults versus immatures in both males (17 compounds, up to 12-fold) and females (13 compounds, up to 3-fold). POP concentrations were detected with compound-specific patterns in nursing calves, confirming maternal offloading for the first time in this species.

Highly contaminated river otters (Lontra canadensis) are effective biomonitors of environmental pollutant exposure.

River otters (Lontra canadensis) are apex predators that bioaccumulate contaminants via their diet, potentially serving as biomonitors of watershed health. They reside throughout the Green-Duwamish River, WA (USA), a watershed encompassing an extreme urbanization gradient, including a US Superfund site slated for a 17-year remediation. The objectives of this study were to document baseline contaminant levels in river otters, assess otters' utility as top trophic-level biomonitors of contaminant exposure, and evaluate the potential for health impacts on this species. We measured a suite of contaminants of concern, lipid content, nitrogen stable isotopes (δ15N), and microsatellite DNA markers in 69 otter scat samples collected from twelve sites. Landcover characteristics were used to group sampling sites into industrial (Superfund site), suburban, and rural development zones. Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ether flame-retardants (PBDEs), dichlorodiphenyl-trichloroethane and its metabolites (DDTs), and polycyclic aromatic hydrocarbons (PAHs) increased significantly with increasing urbanization, and were best predicted by models that included development zone, suggesting that river otters are effective biomonitors, as defined in this study. Diet also played an important role, with lipid content, δ15N or both included in all best models. We recommend river otter scat be included in evaluating restoration efforts in this Superfund site, and as a potentially useful monitoring tool wherever otters are found. We also report ΣPCB and ΣPAH exposures among the highest published for wild river otters, with almost 70% of samples in the Superfund site exceeding established levels of concern.

Decreased Growth Rate Associated with Tissue Contaminants in Juvenile Chinook Salmon Out-Migrating through an Industrial Waterway.

The industrial waterway in Portland Harbor, Oregon, is a migration corridor for a distinct population segment of Chinook Salmon (Upper Willamette River) currently protected by the U.S. Endangered Species Act. Juveniles are exposed to a suite of contaminants during outmigration including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and dichlorodiphenyltrichloroethanes. We collected natural origin subyearling Chinook salmon from sites in and around the industrial harbor to evaluate growth (otolith microstructural analysis) in relation to measured chemical concentrations in tissue. A reduced growth rate was associated with higher tissue contaminant concentrations, particularly mixtures represented by PAHs and certain PCBs, which were elevated in juvenile Chinook collected throughout sites within Portland Harbor relative to those captured upstream. First-year growth is an established predictor of individual survival and eventual reproductive success in Chinook salmon. Therefore, our results indicate that legacy pollution may be limiting the population abundance of threatened Willamette River Chinook salmon, and future habitat remediation or restoration actions may benefit ongoing species recovery efforts.

Contaminant Concentrations in Sediments, Aquatic Invertebrates, and Fish in Proximity to Rail Tracks Used for Coal Transport in the Pacific Northwest (USA): A Baseline Assessment.

Railway transport of coal poses an environmental risk, because coal dust contains polycyclic aromatic hydrocarbons (PAHs), mercury, and other trace metals. In the Pacific Northwest of the United States, proposed infrastructure projects could result in an increase in coal transport by train through the Columbia River corridor. Baseline information is needed on current distributions, levels, and spatial patterns of coal dust-derived contaminants in habitats and organisms adjacent to existing coal transport lines. To that end, we collected aquatic surface sediments, aquatic insects, and juvenile fish in 2014 and 2015 from Horsethief Lake State Park and Steigerwald National Wildlife Refuge, both located in Washington state close to the rail line and within the Columbia River Gorge National Scenic Area. Two subsites in each area were selected: one close to the rail line and one far from the rail line. Detected PAH concentrations were relatively low compared with those measured at more urbanized areas. Some contaminants were measured at higher concentrations at the subsites close to the rail line, but it was not possible to link the contaminants to a definitive source. Trace metal concentrations were only slightly higher than background concentrations, but a few of the more sensitive benchmarks were exceeded, including those for arsenic, lead, and selenium in fish tissue and fluoranthene, cadmium, copper, manganese, nickel, zinc, iron, and arsenic in sediments. At Horsethief Lake, Chinook salmon and yellow perch showed lower total mercury body burdens than other species, but PAH body burdens did not differ significantly among species. Differences in the species caught among subsites and the low number of invertebrate samples rendered food web comparisons difficult, but these data show that the PAHs and trace metals, including mercury, are accumulating in these wetland sites and in some resident organisms.

Seasonal variation of pituitary gonadotropin subunit, brain-type aromatase and sex steroid receptor mRNAs, and plasma steroids during gametogenesis in wild sablefish.

Pituitary-hormone signaling plays critical roles in the onset and progression of gametogenesis in vertebrates. This study characterized expression patterns of pituitary gonadotropin beta-subunits (fshb and lhb), brain-type aromatase (cyp19a1b), androgen (ar1, ar2) and estrogen receptors (esr1, esr2a, esr2b), and changes in plasma steroid levels by liquid chromatography/tandem mass spectrometry in wild sablefish (Anoplopoma fimbria, order Scorpaeniformes) during a complete reproductive cycle. Transcripts for fshb increased during early gametogenesis and peaked in late vitellogenic females and late recrudescent males, while expression of lhb reached maximum levels in periovulatory and spermiating fish. Pituitary levels of cyp19a1b and ar1 were strongly correlated with those of lhb in females and males, increasing during gametogenesis and reaching maximum levels prior to spawning. By contrast, expression of ar2, and the three estrogen receptors differed between female and male sablefish. 17ß-estradiol (E2) was the dominant steroid in females during vitellogenesis, while a range of at least 6 steroids (11ß-hydroxyandrostenedione, testosterone [T], E2, 11-ketotestosterone [11KT], 11-deoxycortisol, and 17α,20ß,21-trihydroxyprogesterone) were detected at similar levels in males during testicular development. Prior to spawning, a marked increase in 4-androstenedione, T, 11KT and E2 was found in both periovulatory females and spermiating males. In conclusion, the concomitant changes in plasma androgen levels and pituitary ar1 expression during gametogenesis suggest a specific role for androgens in pituitary hormone regulation of reproduction in sablefish. Further, our data highlight the importance of E2 during final stages of maturation in this species, which may regulate the transcription of pituitary lhb in a paracrine fashion.

Time Trends of Persistent Organic Pollutants in Benthic and Pelagic Indicator Fishes from Puget Sound, Washington, USA.

We modeled temporal trends in polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and dichlorodiphenyltrichloroethane and its metabolites (DDTs) in two indicator fish species representing benthic and pelagic habitats in Puget Sound, Washington, USA. English sole (Parophrys vetulus, benthic) index sites and larger-scale Pacific herring (Clupea pallasii, pelagic) foraging areas represented a wide range of possible contamination conditions, with sampling locations situated adjacent to watersheds exhibiting high, medium and low development. Consistency in analytical data throughout the study was maintained by either calculating method-bias-correction factors on paired samples as methods evolved or by analyzing older archived samples by current methods. PCBs declined moderately in two herring stocks from a low-development basin (2.3 and 4.0% annual rate of decline) and showed no change in the highly developed and moderately developed basins during a 16- to 21-year period. PCBs increased in English sole from four of ten sites (2.9-7.1%), and the remaining six exhibited no significant change. PBDEs and DDTs declined significantly in all herring stocks (4.2-8.1%), although analytical challenges warrant caution in interpreting DDT results. PBDEs declined in English sole from two high-development and one low-development site (3.7-7.2%) and remained unchanged in the remaining seven. DDTs increased in English sole from one high-development site (Tacoma City Waterway) and declined in two high-development and one low development site. As with herring, analytical challenges warrant caution in interpreting the English sole DDT results. It is likely that source controls and mitigation efforts have contributed to the declines in PBDEs and DDTs overall, whereas PCBs appear to have persisted, especially in the pelagic food web, despite bans in PCB production and use.

Modulation in Persistent Organic Pollutant Concentration and Profile by Prey Availability and Reproductive Status in Southern Resident Killer Whale Scat Samples.

Persistent organic pollutants (POPs), specifically PCBs, PBDEs, and DDTs, in the marine environment are well documented, however accumulation and mobilization patterns at the top of the food-web are poorly understood. This study broadens the understanding of POPs in the endangered Southern Resident killer whale population by addressing modulation by prey availability and reproductive status, along with endocrine disrupting effects. A total of 140 killer whale scat samples collected from 54 unique whales across a 4 year sampling period (2010-2013) were analyzed for concentrations of POPs. Toxicant measures were linked to pod, age, and birth order in genotyped individuals, prey abundance using open-source test fishery data, and pregnancy status based on hormone indices from the same sample. Toxicant concentrations were highest and had the greatest potential for toxicity when prey abundance was the lowest. In addition, these toxicants were likely from endogenous lipid stores. Bioaccumulation of POPs increased with age, with the exception of presumed nulliparous females. The exceptional pattern may be explained by females experiencing unobserved neonatal loss. Transfer of POPs through mobilization of endogenous lipid stores during lactation was highest for first-borns with diminished transfer to subsequent calves. Contrary to expectation, POP concentrations did not demonstrate an associated disruption of thyroid hormone, although this association may have been masked by impacts of prey abundance on thyroid hormone concentrations. The noninvasive method for measuring POP concentrations in killer whales through scat employed in this study may improve toxicant monitoring in the marine environment and promote conservation efforts.

Using Domestic and Free-Ranging Arctic Canid Models for Environmental Molecular Toxicology Research.

The use of sentinel species for population and ecosystem health assessments has been advocated as part of a One Health perspective. The Arctic is experiencing rapid change, including climate and environmental shifts, as well as increased resource development, which will alter exposure of biota to environmental agents of disease. Arctic canid species have wide geographic ranges and feeding ecologies and are often exposed to high concentrations of both terrestrial and marine-based contaminants. The domestic dog (Canis lupus familiaris) has been used in biomedical research for a number of years and has been advocated as a sentinel for human health due to its proximity to humans and, in some instances, similar diet. Exploiting the potential of molecular tools for describing the toxicogenomics of Arctic canids is critical for their development as biomedical models as well as environmental sentinels. Here, we present three approaches analyzing toxicogenomics of Arctic contaminants in both domestic and free-ranging canids (Arctic fox, Vulpes lagopus). We describe a number of confounding variables that must be addressed when conducting toxicogenomics studies in canid and other mammalian models. The ability for canids to act as models for Arctic molecular toxicology research is unique and significant for advancing our understanding and expanding the tool box for assessing the changing landscape of environmental agents of disease in the Arctic.

Persistent Organic Pollutant Determination in Killer Whale Scat Samples: Optimization of a Gas Chromatography/Mass Spectrometry Method and Application to Field Samples.

Biologic sample collection in wild cetacean populations is challenging. Most information on toxicant levels is obtained from blubber biopsy samples; however, sample collection is invasive and strictly regulated under permit, thus limiting sample numbers. Methods are needed to monitor toxicant levels that increase temporal and repeat sampling of individuals for population health and recovery models. The objective of this study was to optimize measuring trace levels (parts per billion) of persistent organic pollutants (POPs), namely polychlorinated-biphenyls (PCBs), polybrominated-diphenyl-ethers (PBDEs), dichlorodiphenyltrichloroethanes (DDTs), and hexachlorocyclobenzene, in killer whale scat (fecal) samples. Archival scat samples, initially collected, lyophilized, and extracted with 70 % ethanol for hormone analyses, were used to analyze POP concentrations. The residual pellet was extracted and analyzed using gas chromatography coupled with mass spectrometry. Method detection limits ranged from 11 to 125 ng/g dry weight. The described method is suitable for p,p'-DDE, PCBs-138, 153, 180, and 187, and PBDEs-47 and 100; other POPs were below the limit of detection. We applied this method to 126 scat samples collected from Southern Resident killer whales. Scat samples from 22 adult whales also had known POP concentrations in blubber and demonstrated significant correlations (p < 0.01) between matrices across target analytes. Overall, the scat toxicant measures matched previously reported patterns from blubber samples of decreased levels in reproductive-age females and a decreased p,p'-DDE/∑PCB ratio in J-pod. Measuring toxicants in scat samples provides an unprecedented opportunity to noninvasively evaluate contaminant levels in wild cetacean populations; these data have the prospect to provide meaningful information for vital management decisions.

Assimilation efficiency of PBDE congeners in Chinook salmon.

Polybrominated diphenyl ether (PBDE) flame retardants are environmental contaminants that can accumulate in biota. PBDE accumulation in an organism depends on exposure, assimilation efficiency, and elimination/metabolism. Net assimilation efficiency represents the fraction of the contaminant that is retained in the organism after exposure. In the present study, congener-specific estimates of net PBDE assimilation efficiencies were calculated from dietary exposures of juvenile Chinook salmon. The fish were exposed to one to eight PBDE congeners up to 1500 ng total PBDEs/g food. Mean assimilation efficiencies varied from 0.32 to 0.50 for BDE congeners 28, 47, 99, 100, 153, and 154. The assimilation efficiency of BDE49 was significantly greater than 100%, suggesting biotransformation from higher brominated congeners. Whole body concentrations of BDE49 significantly increased with both exposure to increasing concentrations of BDE99 and decreasing fish lipid levels, implying lipid-influenced debromination of BDE99 to BDE49. Excluding BDE49, PBDE assimilation efficiency was not significantly related to the numbers of congeners in the diets, or congener hydrophobicity, but was greater in foods with higher lipid levels. Estimates of PBDE assimilation efficiency can be used in bioaccumulation models to assess threats from PBDE exposure to Chinook salmon health and recovery efforts, as well as to their predators.

Development of approaches to induce puberty in cultured female sablefish (Anoplopoma fimbria).

Efforts to establish sustainable and efficient aquaculture production of sablefish (Anoplopoma fimbria) have been constrained by delayed puberty in cultured females. This study integrates a series of experiments aimed at gaining an understanding of the reproductive physiology of puberty in female sablefish. We detected transcripts for the dopamine D2 receptor (drd2) in brain, pituitary and ovary of sablefish, and prepubertal females exhibited significantly elevated brain and pituitary drd2 expression relative to wild maturing females. Treatments with sustained-release cholesterol pellets containing testosterone (T) and the dopamine D2 receptor antagonist, metoclopramide (Met), stimulated expression of pituitary luteinizing hormone beta subunit (lhb) and follicle-stimulating hormone beta subunit (fshb), respectively, in prepubertal females, whereas a combination of T and gonadotropin-releasing hormone agonist (GnRHa) had a strong synergistic effect on lhb expression (2000-fold higher than control). Although T induced a significant increase in the maximum ovarian follicle volume, none of the treatments tested stimulated onset of vitellogenesis. Using liquid chromatography/tandem mass spectrometry, we demonstrated that Met stimulated production of T by previtellogenic ovarian follicles in vitro, whereas gonadotropin preparations enhanced 17α-hydroxyprogesterone, androstenedione (A4), T and 17ß-estradiol (E2) production. Treatment with T increased production of A4, 11ß-hydroxyandrostenedione, 11ß-hydroxytestosterone, E2, 11-ketotestosterone, and 5α-dihydrotestosterone (DHT). Interestingly, in the presence of high doses of T the previtellogenic ovary preferentially produced A4 and DHT over any other metabolite. Our data suggest the existence of dopamine inhibition of the reproductive axis in female sablefish. Treatments with Met and T elevated gonadotropin mRNAs in prepubertal females but failed to stimulate the transition into vitellogenic growth, suggesting a possible failure in pituitary gonadotropin protein synthesis/release. Previtellogenic ovarian follicles of sablefish are equipped to synthesize steroids, including those required for vitellogenic growth, and DHT, a steroid hormone whose role in reproduction of fishes remains unknown.

Federal seafood safety response to the Deepwater Horizon oil spill.

Following the 2010 Deepwater Horizon oil spill, petroleum-related compounds and chemical dispersants were detected in the waters of the Gulf of Mexico. As a result, there was concern about the risk to human health through consumption of contaminated seafood in the region. Federal and Gulf Coast State agencies worked together on a sampling plan and analytical protocols to determine whether seafood was safe to eat and acceptable for sale in the marketplace. Sensory and chemical methods were used to measure polycyclic aromatic hydrocarbons (PAHs) and dispersant in >8,000 seafood specimens collected in federal waters of the Gulf. Overall, individual PAHs and the dispersant component dioctyl sodium sulfosuccinate were found in low concentrations or below the limits of quantitation. When detected, the concentrations were at least two orders of magnitude lower than the level of concern for human health risk. Once an area closed to fishing was free of visibly floating oil and all sensory and chemical results for the seafood species within an area met the criteria for reopening, that area was eligible to be reopened. On April 19, 2011 the area around the wellhead was the last area in federal waters to be reopened nearly 1 y after the spill began. However, as of November 9, 2011, some state waters off the Louisiana coast (Barataria Bay and the Delta region) remain closed to fishing.

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.

Health of common bottlenose dolphins ( Tursiops truncatus ) in Barataria Bay, Louisiana, following the deepwater horizon oil spill.

The oil spill resulting from the explosion of the Deepwater Horizon drilling platform initiated immediate concern for marine wildlife, including common bottlenose dolphins in sensitive coastal habitats. To evaluate potential sublethal effects on dolphins, health assessments were conducted in Barataria Bay, Louisiana, an area that received heavy and prolonged oiling, and in a reference site, Sarasota Bay, Florida, where oil was not observed. Dolphins were temporarily captured, received a veterinary examination, and were then released. Dolphins sampled in Barataria Bay showed evidence of hypoadrenocorticism, consistent with adrenal toxicity as previously reported for laboratory mammals exposed to oil. Barataria Bay dolphins were 5 times more likely to have moderate-severe lung disease, generally characterized by significant alveolar interstitial syndrome, lung masses, and pulmonary consolidation. Of 29 dolphins evaluated from Barataria Bay, 48% were given a guarded or worse prognosis, and 17% were considered poor or grave, indicating that they were not expected to survive. Disease conditions in Barataria Bay dolphins were significantly greater in prevalence and severity than those in Sarasota Bay dolphins, as well as those previously reported in other wild dolphin populations. Many disease conditions observed in Barataria Bay dolphins are uncommon but consistent with petroleum hydrocarbon exposure and toxicity.

Cytochrome P4501A1 expression in blubber biopsies of endangered false killer whales (Pseudorca crassidens) and nine other odontocete species from Hawai'i.

Odontocetes (toothed whales) are considered sentinel species in the marine environment because of their high trophic position, long life spans, and blubber that accumulates lipophilic contaminants. Cytochrome P4501A1 (CYP1A1) is a biomarker of exposure and molecular effects of certain persistent organic pollutants. Immunohistochemistry was used to visualize CYP1A1 expression in blubber biopsies collected by non-lethal sampling methods from 10 species of free-ranging Hawaiian odontocetes: short-finned pilot whale, melon-headed whale, pygmy killer whale, common bottlenose dolphin, rough-toothed dolphin, pantropical spotted dolphin, Blainville's beaked whale, Cuvier's beaked whale, sperm whale, and endangered main Hawaiian Islands insular false killer whale. Significantly higher levels of CYP1A1 were observed in false killer whales and rough-toothed dolphins compared to melon-headed whales, and in general, trophic position appears to influence CYP1A1 expression patterns in particular species groups. No significant differences in CYP1A1 were found based on age class or sex across all samples. However, within male false killer whales, juveniles expressed significantly higher levels of CYP1A1 when compared to adults. Total polychlorinated biphenyl (∑PCBs) concentrations in 84% of false killer whales exceeded proposed threshold levels for health effects, and ∑PCBs correlated with CYP1A1 expression. There was no significant relationship between PCB toxic equivalent quotient and CYP1A1 expression, suggesting that this response may be influenced by agonists other than the dioxin-like PCBs measured in this study. No significant differences were found for CYP1A1 expression among social clusters of false killer whales. This work provides a foundation for future health monitoring of the endangered stock of false killer whales and other Hawaiian odontocetes.

Persistent organic pollutants in female humpback whales Megaptera novaeangliae from the Gulf of Maine.

Contaminant studies in cetaceans can provide information about pollutant levels and patterns in a given region. Due to the confounding effects of reproductive status and maternal offloading in females, these studies typically focus on males. However, an improved understanding of contaminant burdens in female cetaceans is needed to better assess potential impacts to populations. The objectives of this study were to characterize concentrations of persistent organic pollutants (POPs) in blubber of female humpback whales across age classes and to also better characterize maternal offloading of these pollutants to their offspring. A total of 36 blubber biopsy samples of female humpback whales (Megaptera novaeangliae) from the Gulf of Maine were analyzed to examine contaminant loads across females of different ages. Sampled individuals were individually-identified from longitudinal studies and assigned to age class (i.e., adult, subadult, juvenile, calf). Analysis was performed using gas chromatography/mass spectrometry (GC/MS) of POPs including polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs), chlordanes (CHLDs), polybrominated diphenyl ethers (PBDEs), hexachlorocyclohexanes (HCHs). The most abundant POPs were PCB congeners, with summed values ranging from 280 to 12,000 ng/g, lipid weight, which is above recent estimates of the threshold for adverse health effects. We found significant differences in mean values between adults and juveniles and between adults and subadults, with the exception of the less persistent HCHs for the latter. We also found significant differences in mean levels of ∑HCHs between the juveniles and subadults. Changes over age are consistent with maternal offloading and potentially important for evaluating population health and viability.

Assessing hydroxylated polycyclic aromatic hydrocarbon (OHPAH) metabolites in bile of English sole (Parophrys vetulus) from Puget Sound, WA, USA by liquid chromatography/tandem mass spectrometry (LC-MS/MS).

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants that are widely monitored in marine biota from urbanized areas, due to their toxicity to aquatic organisms. Teleost fish can quickly metabolize PAHs into hydroxylated forms (OHPAHs) that, in some cases, are more toxic than the parent (unmetabolized) PAHs. But due to this fast metabolism, monitoring traditional parent PAHs in fish can cause underestimation on assessing PAH exposure. In addition, environmental levels of individual OHPAH metabolites are lacking in the literature worldwide. Therefore, we developed a rapid and accurate analytical method in which a number of individual OHPAHs metabolites are measured simultaneously in fish bile, via liquid chromatography coupled with tandem mass spectrometry, including low and high molecular weight mono- and diol-OHPAHs. We analyzed bile samples of 119 English sole (Parophrys vetulus) collected from 14 Puget Sound, WA, USA, sites, which has multiple sources of PAHs, including urban stormwater runoff, wastewater effluents, as well as an inactive creosote facility. The mean (± SD) biliary summed OHPAH (∑OHPAH) concentrations determined in English sole from urban, near-urban, and non-urban sites were 790 ± 1400 (n = 46), 310 ± 330 (n = 44) and 130 ± 200 (n = 29) ng/mL, respectively, with a maximum reaching 9400 ng/mL in a sample from an urban site. We compared these novel biliary OHPAH metabolite data with parent PAHs measured in stomach content of the same individual sole. Biliary ∑OHPAH concentrations were significantly correlated with the levels of ∑PAH in stomach content, however, with major differences in their distribution. We also demonstrated that biliary OHPAH metabolite data in English sole can potentially be used to distinguish different sampling sites due to a specific variety and intensity of PAH sources in the aquatic environment, which makes this a very important analytical approach for assessing PAH exposure in the environment.

Polycyclic aromatic hydrocarbons and risk to threatened and endangered Chinook salmon in the Lower Columbia River estuary.

Polycyclic aromatic hydrocarbons (PAHs), derived from oil and fuel combustion, are ubiquitous nonpoint source pollutants that can have a number of detrimental effects on fish and wildlife. In this study, we monitored PAH exposure in outmigrant juvenile Chinook salmon from the Lower Columbia River to evaluate the risk that these contaminants might pose to the health and recovery of threatened and endangered salmonids. Juvenile Chinook salmon (Oncorhynchus tshawytscha) were collected by beach seine from five sites in the Lower Columbia River from Bonneville Dam to the mouth of the estuary (Warrendale, the Willamette-Columbia Confluence, Columbia City, Beaver Army Terminal, and Point Adams) and from a site in the Lower Willamette near downtown Portland (Morrison Street Bridge). Sediment samples were also collected at the same sites. Concentrations of PAHs in sediment samples were relatively low at all sites with average total PAH concentrations <1000 ng/g dry weight (wt.). However, we found PAHs in stomach contents of salmon from all sites at concentrations ranging from <100 to >10,000 ng/g wet wt. Metabolites of low and high molecular-weight PAHs were also detected in bile of salmon from all sites; for metabolites fluorescing at phenanthrene (PHN) wavelengths, concentrations ranged from 1.1 to 6.0 µg/mg bile protein. Levels of PAHs in stomach contents and PAH metabolites in bile were highest in salmon from the Morrison Street Bridge site in Portland and the Willamette-Columbia Confluence, Columbia City, and Beaver Army Terminal sites. Mean PAH concentrations measured in some stomach content samples from the Columbia City, Beaver Army Terminal, and Morrison Street Bridge sites were near the threshold concentration (approximately 7200-7600 ng/g wet wt.) associated with variability and immune dysfunction in juvenile salmonids (Meador et al., Can J Fish Aquat Sci 63:2364-2376, 2006; Bravo et al., Environ Toxicol Chem 30:704-714, 2011). Mean levels of biliary fluorescent aromatic compounds (FACs)-PHN in juvenile Chinook collected at the Morrison Street Bridge site in Portland, at the Confluence and Columbia City sites, and at the Beaver Army Terminal site were at or above a threshold effect concentration of 2 µg/mg protein for FACs-PHN linked to growth impairment, altered energetics, and reproductive effects (Meador et al., Environ Toxicol Chem 27(4):845-853, 2008). These findings suggest that PAHs in the food chain are a potential source of injury to juvenile salmon in the Lower Columbia and Lower Willamette rivers.

Chemical contaminant levels in edible seaweeds of the Salish Sea and implications for their consumption.

Despite growing interest in edible seaweeds, there is limited information on seaweed chemical contaminant levels in the Salish Sea. Without this knowledge, health-based consumption advisories can not be determined for consumers that include Tribes and First Nations, Asian and Pacific Islander community members, and recreational harvesters. We measured contaminant concentrations in edible seaweeds (Fucus distichus, F. spiralis, and Nereocystis luetkeana) from 43 locations in the Salish Sea. Metals were analyzed in all samples, and 94 persistent organic pollutants (POPs) (i.e. 40 PCBs, 15 PBDEs, 17 PCDD/Fs, and 22 organochlorine pesticides) and 51 PAHs were analyzed in Fucus spp. We compared concentrations of contaminants to human health-based screening levels calculated from the USEPA and to international limits. We then worked with six focal contaminants that either exceeded screening levels or international limits (Cd, total Hg, Pb, benzo[a]pyrene [BaP], and PCBs) or are of regional interest (total As). USEPA cancer-based screening levels were exceeded in 30 samples for the PCBs and two samples for BaP. Cadmium concentrations did not exceed the USEPA noncancer-based screening level but did exceed international limits at all sites. Lead exceeded international limits at three sites. Because there are no screening levels for total Hg and total As, and to be conservative, we made comparisons to methyl Hg and inorganic As screening levels. All samples were below the methyl Hg and above the inorganic As screening levels. Without knowledge of the As speciation, we cannot assess the health risk associated with the As. While seaweed was the focus, we did not consider contaminant exposure from consuming other foods. Other chemicals, such as contaminants of emerging concern (e.g., PFAS, pharmaceuticals and personal care products), should also be considered. Additionally, although we focused on toxicological aspects, there are cultural and health benefits of seaweed use that may affect consumer choice.