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.

Geographic variation of persistent organic pollutant levels in humpback whale (Megaptera novaeangliae) feeding areas of the North Pacific and North Atlantic.

Seasonal feeding behavior and high fidelity to feeding areas allow humpback whales (Megaptera novaeangliae) to be used as biological indicators of regional contamination. Biopsy blubber samples from male individuals (n = 67) were collected through SPLASH, a multinational research project, in eight North Pacific feeding grounds. Additional male samples (n = 20) were collected from one North Atlantic feeding ground. Persistent organic pollutants were measured in the samples and used to assess contaminant distribution in the study areas. North Atlantic (Gulf of Maine) whales were more contaminated than North Pacific whales, showing the highest levels of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and chlordanes. The highest dichlorodiphenyltrichloroethane (DDT) levels were detected in whales feeding off southern California, USA. High-latitude regions were characterized by elevated levels of hexachlorocyclohexanes (HCHs) but generally nondetectable concentrations of PBDEs. Age was shown to have a positive relationship with SigmaPCBs, SigmaDDTs, Sigmachlordanes, and total percent lipid. Contaminant levels in humpback whales were comparable to other mysticetes and lower than those found in odontocete cetaceans and pinnipeds. Although these concentrations likely do not represent a significant conservation threat, levels in the Gulf of Maine and southern California may warrant further study.

Organochlorine contaminants in endangered Steller sea lion pups (Eumetopias jubatus) from western Alaska and the Russian Far East.

Investigations into the cause of the Steller sea lion population decline have focused on numerous factors, including exposure to toxic contaminants such as organochlorines (OCs). OCs, such as polychlorinated biphenyls (PCBs), 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, or dichlorodiphenyltrichloroethane (DDT), have been associated with various biological effects in marine mammals. We measured these compounds in whole blood of free-ranging Steller sea lion pups in order to determine the extent and magnitude of contamination across their geographical range. Of 212 pups analyzed for OCs, 76 pups (36 females and 40 males) were from western Alaska and the other 136 (63 females and 73 males) were from the Russian Far East. Concentrations of summation SigmaPCBs in the whole blood of pups from western Alaska ranged from 0.21 to 13 ng/g wet weight with a mean of 2.1+/-0.27 ng/g wet weight. In the Russian animals, summation SigmaPCB concentrations in the whole blood of pups ranged from 0.33 to 36 ng/g wet weight with a mean of 4.3+/-0.44 ng/g wet weight. summation SigmaDDT concentrations in the whole blood of pups from western Alaska ranged from 0.18 to 11 ng/g wet weight with a mean of 1.6+/-0.23 ng/g wet weight. In Russia, summation SigmaDDT in the whole blood of pups ranged from undetectable to 26 ng/g wet weight with a mean of 3.3+/-0.36 ng/g wet weight. Average OC concentrations were significantly higher in the blood of Russian animals compared to western Alaska (for PCBs and DDTs, p<0.001) and in both areas females had higher concentrations than males. Male pups from western Alaska had significantly lower levels of summation SigmaPCBs and summation SigmaDDT when compared to male pups from Russia (for PCBs and DDTs p<0.001). Female pups from western Alaska were significantly lower in summation SigmaPCBs than Russian female pups (for PCBs p=0.009) as were female pups for summation SigmaDDT levels between areas (for DDTs p=0.026). OC contaminants data indicate that Steller sea lion pups have measurable concentrations of these synthetic chemicals. While any physiological effect and the specific role these chemicals may have in either the decline or the failure of the endangered Steller sea lion population to recover needs to be further investigated, this study indicates specific areas and animals that may be most at risk.

Organochlorine contaminants in endangered Hawaiian monk seals from four subpopulations in the Northwestern Hawaiian Islands.

We analyzed blubber and blood samples for organochlorines (OCs) from 158 Hawaiian monk seals (Monachus schauinslandi) at four of their six primary breeding colonies in the Northwestern Hawaiian Islands. Levels of OCs in blubber were lower in adult females compared to juveniles or adult males, evidently owing to the transfer of these lipophilic compounds to pups by pregnant and lactating females. Concentrations of SigmaPCBs and p,p'-DDE in blubber generally increased with age until seals were sexually mature and then continued to increase with age in males after puberty. Average levels of PCBs and PCB toxic equivalents (TEQs) in blubber were significantly higher in adult male and juvenile seals at Midway Atoll than the same age class of seals at the other colonies. Unlike concentrations of OCs in blubber, circulating levels of OCs in blood did not vary consistently among age classes of seals or among breeding colonies. Though the concentrations of OCs measured in Hawaiian monk seals were generally equal to or lower than those reported for other pinniped species in the North Pacific Ocean, they were high enough in a few seals to potentially affect their health.

Use of chemical tracers in assessing the diet and foraging regions of eastern North Pacific killer whales.

Top predators in the marine environment integrate chemical signals acquired from their prey that reflect both the species consumed and the regions from which the prey were taken. These chemical tracers-stable isotope ratios of carbon and nitrogen; persistent organic pollutant (POP) concentrations, patterns and ratios; and fatty acid profiles-were measured in blubber biopsy samples from North Pacific killer whales (Orcinus orca) (n=84) and were used to provide further insight into their diet, particularly for the offshore group, about which little dietary information is available. The offshore killer whales were shown to consume prey species that were distinctly different from those of sympatric resident and transient killer whales. In addition, it was confirmed that the offshores forage as far south as California. Thus, these results provide evidence that the offshores belong to a third killer whale ecotype. Resident killer whale populations showed a gradient in stable isotope profiles from west (central Aleutians) to east (Gulf of Alaska) that, in part, can be attributed to a shift from off-shelf to continental shelf-based prey. Finally, stable isotope ratio results, supported by field observations, showed that the diet in spring and summer of eastern Aleutian Island transient killer whales is apparently not composed exclusively of Steller sea lions.

Persistent organic pollutants and stable isotopes in biopsy samples (2004/2006) from Southern Resident killer whales.

"Southern Resident" killer whales include three "pods" (J, K and L) that reside primarily in Puget Sound/Georgia Basin during the spring, summer and fall. This population was listed as "endangered" in the US and Canada following a 20% decline between 1996 and 2001. The current study, using blubber/epidermis biopsy samples, contributes contemporary information about potential factors (i.e., levels of pollutants or changes in diet) that could adversely affect Southern Residents. Carbon and nitrogen stable isotopes indicated J- and L-pod consumed prey from similar trophic levels in 2004/2006 and also showed no evidence for a large shift in the trophic level of prey consumed by L-pod between 1996 and 2004/2006. Sigma PCBs decreased for Southern Residents biopsied in 2004/2006 compared to 1993-1995. Surprisingly, however, a three-year-old male whale (J39) had the highest concentrations of Sigma PBDEs, Sigma HCHs and HCB. POP ratio differences between J- and L-pod suggested that they occupy different ranges in winter.

Metabolites in bile of fish from São Sebastião Channel, São Paulo, Brazil as biomarkers of exposure to petrogenic polycyclic aromatic compounds.

This study reports the analysis of polycyclic aromatic compound (PAC) metabolites, as biomarkers of exposure to PACs in marine environment. PAC metabolites were measured in bile samples from 14 species of demersal fish caught in the São Sebastião Channel (SSC), SE Brazilian coastline. Naphthalene (NPH) equivalents, phenanthrene (PHN) equivalents, and benzo[a]pyrene (BaP) equivalents were quantified using a reverse-phase high-performance liquid chromatography coupled with fluorescence detection method. For all samples, the means (+/-standard deviation, n=37) of concentrations obtained for NPH, PHN, and BaP equivalents were, respectively, 290,000+/-200,000 ng/g, 18,000+/-14,000 ng/g, and 970+/-1900 ng/g. These results indicate recent exposure of these fish to PACs in their environment. In addition, two species (Cyclichthys spinosus and Prionotus nudigula) of fish were analyzed in order to investigate local sources of PAC contamination in the SSC and the influence of the petroleum terminal in fish caught in remote areas. The results showed that these fish species potentially migrate along the channel, especially P. nudigula. Correlations among groups of PAC metabolites indicate the same petrogenic source for NPH and PHN equivalents and a combustion source (e.g., automobile, ships) for BaP equivalents. The ratio BaP/PHN equivalents (0.05+/-0.07, n=37) confirms the predominance of petrogenic PACs for contamination by these chemicals in this region.

Contaminant exposure and effects in pinnipeds: implications for Steller sea lion declines in Alaska.

After nearly 3 decades of decline, the western stock of Steller sea lions (SSL; Eumetopias jubatus) was listed as an endangered species in 1997. While the cause of the decline in the 1970s and 1980s has been attributed to nutritional stress, recent declines are unexplained and may result from other factors including the presence of environmental contaminants. SSL tissues show accumulation of butyltins, mercury, PCBs, DDTs, chlordanes and hexachlorobenzene. SSL habitats and prey are contaminated with additional chemicals including mirex, endrin, dieldrin, hexachlorocyclohexanes, tetrachlorodibenzo-p-dioxin (TCDD) and related compounds, cadmium and lead. In addition, many SSL haulouts and rookeries are located near other hazards including radioactivity, solvents, ordnance and chemical weapon dumps. PCB and DDT concentrations measured in a few SSL during the 1980s were the highest recorded for any Alaskan pinniped. Some contaminant exposures in SSL appear to be elevated in the Gulf of Alaska and Bering Sea compared to southeast Alaska, but there are insufficient data to evaluate geospatial relationships with any certainty. Based on very limited blubber data, current levels of PCBs may not pose a risk to SSL based on comparison to immunotoxicity tissue benchmarks, but SSL may have been at risk from pre-1990 PCB exposures. While exposure to PCBs and DDTs may be declining, SSL are likely exposed to a multitude of other contaminants that have not been monitored. The impacts of these exposures on SSL remain unknown because causal effects have not been established. Field studies with SSL have been limited in scope and have not yet linked contaminant exposures to adverse animal health or population effects. Several biomarkers may prove useful for monitoring exposure and additional research is needed to evaluate their utility in SSL. We conclude that there are insufficient data to reject the hypothesis that contaminants play a role in the continued decline of SSL, and suggest that a coordinated monitoring program be developed which can be related to key biological, ecological and laboratory toxicity data.

Analytical methods for determining metabolites of polycyclic aromatic hydrocarbon (PAH) pollutants in fish bile: A review.

The determination of polycyclic aromatic hydrocarbon (PAH) metabolites in bile can serve as a tool for assessing environmental PAH exposure in fish. Biliary PAH metabolite levels can be measured using several analytical methods, including simple fluorescence assays (fixed fluorescence detection or synchronous fluorescence spectrometry); high-performance liquid chromatography with fluorescence detection (HPLC-F); gas chromatography-mass spectrometry (GC-MS) after deconjugation, extraction and derivatization of the bile sample, and finally by advanced liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS) methods. The method alternatives are highly different both with regard to their analytical performance towards different PAH metabolite structures as well as in general technical demands and their suitability for different monitoring strategies. In the present review, the state-of-the-art for these different analytical methods is presented and the advantages and limitations of each approach as well as aspects related to analytical quality control and inter-laboratory comparability of data and availability of certified reference materials are discussed.

Effects of age, sex and reproductive status on persistent organic pollutant concentrations in "Southern Resident" killer whales.

"Southern Resident" killer whales (Orcinus orca) that comprise three fish-eating "pods" (J, K and L) were listed as "endangered" in the US and Canada following a 20% population decline between 1996 and 2001. Blubber biopsy samples from Southern Resident juveniles had statistically higher concentrations of certain persistent organic pollutants than were found for adults. Most Southern Resident killer whales, including the four juveniles, exceeded the health-effects threshold for total PCBs in marine mammal blubber. Maternal transfer of contaminants to the juveniles during rapid development of their biological systems may put these young whales at greater risk than adults for adverse health effects (e.g., immune and endocrine system dysfunction). Pollutant ratios and field observations established that two of the pods (K- and L-pod) travel to California to forage. Nitrogen stable isotope values, supported by field observations, indicated possible changes in the diet of L-pod over the last decade.

Persistent organic pollutants in Alaskan ringed seal (Phoca hispida) and walrus (Odobenus rosmarus) blubber.

Since 1987, the Alaska Marine Mammal Tissue Archival Project (AMMTAP) has collected tissues from 18 marine mammal species. Specimens are archived in the National Institute of Standards and Technology's National Biomonitoring Specimen Bank (NIST-NBSB). AMMTAP has collected blubber, liver and/or kidney specimens from a number of ringed seals (Phoca hispida) from the areas near Nome and Barrow, Alaska and walruses (Odobenus rosmarus) from several locations in the Bering Sea. Thirty-three ringed seal and 15 walrus blubber samples from the NIST-NBSB were analyzed for persistent organic pollutants (POPs). The compounds determined included PCBs (28 congeners or congener groups), DDT and related compounds, hexachlorobenzene (HCB), hexachlorocyclohexane isomers (HCHs), chlordanes, dieldrin, and mirex. POP concentrations in ringed seal blubber were significantly higher in Barrow than in Nome when statistically accounting for the interaction of age and gender; HCB, however, was not statistically different between the two locations. Unlike males, POP concentrations and age were not significantly correlated in females probably as a result of lactational loss. POP concentrations in walrus blubber were lower than in ringed seal blubber for SigmaPCBs, chlordanes, and HCHs, but higher for dieldrin and mirex. POP concentrations in ringed seals and walrus from Alaska provide further evidence that the western Arctic tends to have lower or similar POP concentrations compared to the eastern Canadian Arctic.