Polycyclic aromatic hydrocarbons in Pacific herring (Clupea pallasii) embryos exposed to creosote-treated pilings during a piling-removal project in a nearshore marine habitat of Puget Sound

We used manually spawned, field-deployed embryos of a common marine fish species, Pacific herring (Clupea pallasii), to evaluate accumulation of polycyclic aromatic hydrocarbons (PAHs) associated with an incomplete creosote-treated piling (CTP) removal project. Embryos near undisturbed 100-year-old CTPs (before removal) accumulated higher PAHs and exhibited higher cyp1a gene expression than embryos from reference areas. Embryos incubated close to CTP debris after CTP removal showed PAHs 90 times higher than reference areas up to a year after CTP removal. cyp1a fold-induction correlated with total embryo PAHs in all three years. Patterns of individual PAH chemicals differed slightly between embryos, wood sampled from CTPs, and passive samplers. This study illustrates the importance of using appropriate techniques and procedures to remove CTPs in aquatic environments to prevent release of toxic chemicals. Of particular concern is that incomplete CTP removal could expose sensitive life stages of fishes to chemicals that may reduce their survival.

Coho salmon spawner mortality in western US urban watersheds: bioinfiltration prevents lethal storm water impacts

Adult coho salmon Oncorhynchus kisutch return each autumn to freshwater spawning habitats throughout western North America. The migration coincides with increasing seasonal rainfall, which in turn increases storm water run-off, particularly in urban watersheds with extensive impervious land cover. Previous field assessments in urban stream networks have shown that adult coho are dying prematurely at high rates (>50%). Despite significant management concerns for the long-term conservation of threatened wild coho populations, a causal role for toxic run-off in the mortality syndrome has not been demonstrated.We exposed otherwise healthy coho spawners to: (i) artificial storm water containing mixtures of metals and petroleum hydrocarbons, at or above concentrations previously measured in urban run-off; (ii) undiluted storm water collected from a high traffic volume urban arterial road (i.e. highway run-off); and (iii) highway run-off that was first pre-treated via bioinfiltration through experimental soil columns to remove pollutants.We find that mixtures of metals and petroleum hydrocarbons - conventional toxic constituents in urban storm water - are not sufficient to cause the spawner mortality syndrome. By contrast, untreated highway run-off collected during nine distinct storm events was universally lethal to adult coho relative to unexposed controls. Lastly, the mortality syndrome was prevented when highway run-off was pretreated by soil infiltration, a conventional green storm water infrastructure technology.Our results are the first direct evidence that: (i) toxic run-off is killing adult coho in urban watersheds, and (ii) inexpensive mitigation measures can improve water quality and promote salmon survival. Synthesis and applications. Coho salmon, an iconic species with exceptional economic and cultural significance, are an ecological sentinel for the harmful effects of untreated urban run-off. Wild coho populations cannot withstand the high rates of mortality that are now regularly occurring in urban spawning habitats. Green storm water infrastructure or similar pollution prevention methods should be incorporated to the maximal extent practicable, at the watershed scale, for all future development and redevelopment projects, particularly those involving transportation infrastructure.

Deepwater Horizon crude oil impacts the developing hearts of large predatory pelagic fish

The Deepwater Horizon disaster released more than 636 million L of crude oil into the northern Gulf of Mexico. The spill oiled upper surface water spawning habitats for many commercially and ecologically important pelagic fish species. Consequently, the developing spawn (embryos and larvae) of tunas, swordfish, and other large predators were potentially exposed to crude oil-derived polycyclic aromatic hydrocarbons (PAHs). Fish embryos are generally very sensitive to PAH-induced cardiotoxicity, and adverse changes in heart physiology and morphology can cause both acute and delayed mortality. Cardiac function is particularly important for fast-swimming pelagic predators with high aerobic demand. Offspring for these species develop rapidly at relatively high temperatures, and their vulnerability to crude oil toxicity is unknown. We assessed the impacts of field-collected Deepwater Horizon (MC252) oil samples on embryos of three pelagic fish: bluefin tuna, yellowfin tuna, and an amberjack. We show that environmentally realistic exposures (1-15 µg/L total PAH) cause specific dose-dependent defects in cardiac function in all three species, with circulatory disruption culminating in pericardial edema and other secondary malformations. Each species displayed an irregular atrial arrhythmia following oil exposure, indicating a highly conserved response to oil toxicity. A considerable portion of Gulf water samples collected during the spill had PAH concentrations exceeding toxicity thresholds observed here, indicating the potential for losses of pelagic fish larvae. Vulnerability assessments in other ocean habitats, including the Arctic, should focus on the developing heart of resident fish species as an exceptionally sensitive and consistent indicator of crude oil impacts.

Exxon Valdez to Deepwater Horizon: comparable toxicity of both crude oils to fish early life stages

The 2010 Deepwater Horizon disaster in the Gulf of Mexico was the largest oil spill in United States history. Crude oils are highly toxic to developing fish embryos, and many pelagic fish species were spawning in the northern Gulf in the months before containment of the damaged Mississippi Canyon 252 (MC252) wellhead (April-July). The largest prior U.S. spill was the 1989 grounding of the Exxon Valdez that released 11 million gallons of Alaska North Slope crude oil (ANSCO) into Prince William Sound. Numerous studies in the aftermath of the Exxon Valdez spill defined a conventional crude oil injury phenotype in fish early life stages, mediated primarily by toxicity to the developing heart. To determine whether this type of injury extends to fishes exposed to crude oil from the Deepwater Horizon - MC252 incident, we used zebrafish to compare the embryotoxicity of ANSCO alongside unweathered and weathered MC252 oil. We also developed a standardized protocol for generating dispersed oil water-accommodated fractions containing microdroplets of crude oil in the size range of those detected in subsurface plumes in the Gulf. We show here that MC252 oil and ANSCO cause similar cardiotoxicity and photo-induced toxicity in zebrafish embryos. Morphological defects and patterns of cytochrome P450 induction were largely indistinguishable and generally correlated with polycyclic aromatic compound (PAC) composition of each oil type. Analyses of embryos exposed during different developmental windows provided additional insight into mechanisms of crude oil cardiotoxicity. These findings indicate that the impacts of MC252 crude oil on fish embryos and larvae are consistent with the canonical ANSCO cardiac injury phenotype. For those marine fish species that spawned in the northern Gulf of Mexico during and after the Deepwater Horizon incident, the established literature can therefore inform the assessment of natural resource injury in the form of potential year-class losses.

Effects of exercise on S-IGA and URS in postmenopausal women

32 postmenopausal women were randomized to a 16-week home-based walking program or control group. Before and after the intervention, each subject completed a graded maximal treadmill test to establish VO(2)max and resting saliva was collected to determine levels of salivary immunoglobulin A. The 16-week walking program resulted in an increase in VO(2)max (+10.4%; p<0.01). Repeated measures ANOVA revealed a marked increase in the resting secretion rate of salivary immunoglobulin A (+37.4%; p<0.05) in the exercise group following training. Independent of study group, both before and after the intervention, the secretion rate of salivary immunoglobulin A ( - 32.3%) and saliva flow rate (- 29.3%) were reduced following acute maximal exercise (p<0.05). Weekly upper respiratory symptomatology logs revealed that the number of incidences of upper respiratory symptoms throughout the intervention period were the same and the duration per incidence (control: 5.3±1.5 days; exercise: 6.3±2.2 days) were similar between study groups. These findings in postmenopausal women support that the secretion rate of salivary immunoglobulin A and saliva flow rate are reduced immediately following maximal exercise. Moreover, a 16-week moderate intense walking program can increase the secretion of salivary immunoglobulin A without affecting upper respiratory symptomatology.

Natural sunlight and residual fuel oils are an acutely lethal combination for fish embryos

The majority of studies characterizing the mechanisms of oil toxicity in fish embryos and larvae have focused largely on unrefined crude oil. Few studies have addressed the toxicity of modern bunker fuels, which contain residual oils that are the highly processed and chemically distinct remains of the crude oil refinement process. Here we use zebrafish embryos to investigate potential toxicological differences between unrefined crude and residual fuel oils, and test the effects of sunlight as an additional stressor. Using mechanically dispersed oil preparations, the embryotoxicity of two bunker oils was compared to a standard crude oil from the Alaska North Slope. In the absence of sunlight, all three oils produced the stereotypical cardiac toxicity that has been linked to the fraction of tricyclic aromatic compounds in an oil mixture. However, the cardiotoxicity of bunker oils did not correlate strictly with the concentrations of tricyclic compounds. Moreover, when embryos were sequentially exposed to oil and natural sunlight, the bunker oils produced a rapid onset cell-lethal toxicity not observed with crude oil. To investigate the chemical basis of this differential toxicity, a GC/MS full scan analysis was used to identify a range of compounds that were enriched in the bunker oils. The much higher phototoxic potential of chemically distinct bunker oils observed here suggests that this mode of action should be considered in the assessment of bunker oil spill impacts, and indicates the need for a broader approach to understanding the aquatic toxicity of different oils.

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.

Cardiac arrhythmia is the primary response of embryonic Pacific herring (Clupea pallasi) exposed to crude oil during weathering

Teleost embryos develop a syndrome characterized by edema when exposed to water that weathers substrates contaminated with crude oil. Previous studies using zebrafish demonstrated that crude oil exposure causes cardiogenic edema, and that the most abundant polycyclic aromatic hydrocarbons (PAHs) in weathered crude oils (tricyclic fluorenes, dibenzothiophenes, and phenanthrenes) are cardiotoxic, causing arrhythmia through a pathway that does not require activation of the aryl hydrocarbon receptor (AHR). We demonstrate here for Pacific herring, a species impacted by the Exxon Valdez oil spill, that the developing heart is the primary target of crude oil exposure. Herring embryos exposed to the effluent of oiled gravel columns developed dose-dependent edema and irregular cardiac arrhythmia soon afterthe heartbeat was established. At a dose that produced cardiac dysfunction in 100% of exposed embryos, tissue levels of tricyclic PAHs were below 1 micromol/kg, suggesting a specific, high affinity target in the heart. These findings have implications for understanding the mechanism of tricyclic PAH cardiotoxicity, the development of biomarkers for the effects of PAH exposure in fish, and understanding the long-term impacts of oil spills and other sources of PAH pollution in aquatic environments.

Semipermeable membrane devices link site-specific contaminants to effects: PART II - A comparison of lingering Exxon Valdez oil with other potential sources of CYP1A inducers in Prince William Sound, Alaska

We deployed semipermeable membrane devices (SPMDs) on beaches for 28 days at 53 sites in Prince William Sound (PWS), Alaska, to evaluate the induction potential from suspected sources of cytochrome P450 1A (CYP1A)-inducing contaminants. Sites were selected to assess known point sources, or were chosen randomly to evaluate the region-wide sources. After deployment, SPMD extracts were analyzed chemically for persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAH). These results were compared with hepatic CYP1A enzyme activity of juvenile rainbow trout injected with the same extracts prior to clean-up for the chemical analyses. Increased CYP1A activity was strongly associated with PAH concentrations in extracts, especially chrysene homologues but was not associated with POPs. The only apparent sources of chrysene homologues were lingering oil from Exxon Valdez, asphalt and bunker fuels released from storage tanks during the 1964 Alaska earthquake, creosote leaching from numerous pilings at one site, and PAH-contaminated sediments at Cordova Harbor. Our results indicate that PWS is remarkably free of pollution from PAH when nearby sources are absent as well as from pesticides and PCBs generally.

Persistent organic pollutants in outmigrant juvenile chinook salmon from the Lower Columbia Estuary, USA

Although chemical contaminants are recognized as a potential factor contributing to the salmon declines in the Pacific Northwest, United States, information on contaminant concentrations in threatened and endangered salmon from the Columbia Estuary is limited. In this study we monitored exposure to several persistent organic pollutants [polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs) and other organochlorine pesticides] in outmigrant juvenile fall chinook salmon (Oncorhynchus tschawytscha) in the Lower Columbia River, and evaluated the potential for adverse effects on salmon and the estuarine food web. Contaminants were measured in whole bodies and stomach contents of subyearling to yearling chinook collected in 2001 and 2002 from sites near the confluence of the Columbia and Willamette Rivers, Longview, and within the lower Estuary. The contaminants detected at highest concentrations in salmon whole bodies were PCBs and DDTs. Average concentrations of PCBs in salmon from the sampling sites ranged from 1300 to 14,000 ng/g lipid, in some cases exceeding the recently estimated threshold for adverse health effects in juvenile salmonids of 2400 ng/g lipid. Average DDT concentrations ranged from 1800 to 27,000 ng/g lipid. These levels are among the highest measured in juvenile salmon from Pacific Northwest estuaries to date. Concentrations of PCBs and DDTs in salmon whole bodies showed no clear spatial gradient from the Willamette/Columbia Confluence to the mouth of the Columbia, but tended to be higher in larger fish and older fish, suggesting a correlation with estuarine residence time. PCBs, DDTs, and PAHs were all found in salmon stomach contents, indicating that prey is a source of exposure. Hatchery feed may have contributed to contaminant body burdens in those fish that were of hatchery origin. Contaminant body burdens in salmon were poorly correlated with contaminant concentrations previously measured in local bed sediments, suggesting that pelagic as well as benthic sources are important in determining salmon exposure.

Aryl hydrocarbon receptor-independent toxicity of weathered crude oil during fish development

Polycyclic aromatic hydrocarbons (PAHs), derived largely from fossil fuels and their combustion, are pervasive contaminants in rivers, lakes, and nearshore marine habitats. Studies after the Exxon Valdez oil spill demonstrated that fish embryos exposed to low levels of PAHs in weathered crude oil develop a syndrome of edema and craniofacial and body axis defects. Although mechanisms leading to these defects are poorly understood, it is widely held that PAH toxicity is linked to aryl hydrocarbon receptor (AhR) binding and cytochrome P450 1A (CYP1A) induction. Using zebrafish embryos, we show that the weathered crude oil syndrome is distinct from the well-characterized AhR-dependent effects of dioxin toxicity. Blockade of AhR pathway components with antisense morpholino oligonucleotides demonstrated that the key developmental defects induced by weathered crude oil exposure are mediated by low-molecular-weight tricyclic PAHs through AhR-independent disruption of cardiovascular function and morphogenesis. These findings have multiple implications for the assessment of PAH impacts on coastal habitats.

Screening for planar chlorobiphenyl congeners in tissues of marine biota by high-performance liquid chromatography with photodiode array detection

A rapid method has been developed to screen for planar chlorobiphenyl (CB) congeners, as well as certain other CBs and DDTs, in tissue samples from marine biota. The analytes were extracted from tissue matrices with 1:1 hexane/pentane (v/v) and interfering compounds were separated from the CBs on a gravity-flow column packed with acidic, basic and neutral silica gel eluted with 1:1 hexane/methylene chloride (v/v). Subsequently, the planar CB congeners were resolved from the DDTs and other CBs by HPLC on Cosmosil PYE analytical columns cooled to 9 degrees C and were measured by an ultraviolet (UV) photodiode array (PDA) detector. Two important advantages of PDA over conventional UV detection were the ability to identify individual analytes by comparing their UV spectra to those of reference standards and the ability to establish the spectral homogeneity (purity) of the analytes by comparing spectra within a peak to the apex spectrum. The HPLC/PDA method was tested with tissue samples from fish, shellfish and marine mammals; concentrations of certain CBs and DDTs in samples determined by screening compared favorably with those in the same samples analyzed by a comprehensive method (e.g., gas chromatography/high resolution mass spectrometry). However, the HPLC/PDA method was about an order of magnitude less sensitive than determinations by comprehensive methods.

Chemical contaminants in gray whales (Eschrichtius robustus) stranded along the west coast of North America

The concentrations of selected chlorinated hydrocarbons (e.g. PCBs, DDTs, DDEs, chlordanes) and essential (e.g. zinc, selenium, copper) and toxic (e.g. mercury, lead, arsenic) elements were measured in tissues and stomach contents from 22 gray whales (Eschrichtius robustus) stranded between 1988 and 1991 at sites from the relatively pristine areas of Kodiak Island, AK, to more urbanized areas in Puget Sound, WA, and San Francisco Bay, CA. The majority of animals were stranded at sites on the Washington outer coast and in Puget Sound. The gray whale has the unique feeding strategy among Mysticeti of filtering sediments to feed on benthic (bottom dwelling) invertebrates. Thus, the wide geographical distribution of the stranded whales allowed (1) an initial assessment of whether concentrations of chemical contaminants in these whales exhibited region specific differences and (2) whether toxic chemicals that accumulate in sediments may have contributed to the mortality and stranding of gray whales near the more polluted urban areas. Analyses for chlorinated hydrocarbons in blubber from 22 animals showed no apparent significant differences among stranding sites. The concentrations of sigma PCBs and sigma DDEs in blubber, for example, ranged from 120 to 10,000 and 9 to 2100 p.p.b. (ng/g) wet weight, respectively. Additionally, analyses of chlorinated hydrocarbons and selected elements in liver (n = 10) also showed no apparent significant differences between whales stranded in Puget Sound and whales stranded at more pristine sites (Alaska, Washington outer coast and Strait of Juan de Fuca and Strait of Georgia). For example, the concentrations of sigma PCBs and sigma DDEs in liver ranged from 79 to 1600 and 7 to 280 p.p.b., respectively, and the concentrations of the toxic elements, mercury and lead ranged from 9 to 120 and 20 to 270 p.p.b., respectively. Analyses of stomach contents revealed low concentrations of chlorinated hydrocarbons, but high concentrations (wet weight) of aluminum (1,700,000 +/- 450,000 p.p.b.), iron (320,000 +/- 250,000 p.p.b.), manganese (23,000 +/- 15,000 p.p.b.), and chromium (3400 +/- 1300 p.p.b.), but no significant differences were observed between whales stranded in Puget Sound compared to whales stranded at the more pristine sites. The relative proportions of these elements in stomach contents of stranded whales were similar to the relative proportions in sediments, which is consistent with a geological source of these elements from the ingestion of sediment during feeding. Thus, overall, the concentrations of anthropogenic chemicals in stranded gray whales showed little relation to the levels of chemical contaminants at the stranding sites.(ABSTRACT TRUNCATED AT 400 WORDS)