Cheryl A. Krone

Chemical contaminants in harbor porpoise (Phocoena phocoena) from the North Atlantic coast: Tissue concentrations and intra- and inter-organ distribution

Concentrations of chlorinated hydrocarbons (CHs), such as polychlorinated biphenyls (PCBs), were measured in subsamples taken from different anatomical locations of blubber and liver of three apparently healthy harbor porpoises (Phocoena phocoena) incidentally caught in a gill-net fishery along the northwest Atlantic coast; selected elements (e.g., mercury) were measured in subsamples of liver. The vertical distribution (skin to muscle) of contaminants within blubber was also determined. Additionally, the concentrations of CHs and elements were determined in individual samples of brain, lung, kidney, and testis to assess how the disposition of toxic chemicals may be dependent on the physiological characteristics of a specific organ. Statistical analyses of the results showed that the anatomical location of the blubber or liver sample had no significant effect on concentrations of either CHs in blubber and liver, or of selected elements in liver. However, there were statistical differences between strata of blubber (skin to muscle) for the concentrations of CHs. As expected, the results showed that the CH concentrations, based on wet weight, were considerably higher in the blubber than in the other tissues; however, the concentrations of CHs in the different tissues were more comparable when values were based on total lipid weight with the exception of the brain where lipid normalized concentrations were lower than in all other tissues: This low relative accumulation of lipophilic contaminants in the brain tissue may be due to the presence of the blood-brain barrier, or due to a lower proportion of neutral lipids, such as triglycerides, as analysis for percent lipid and for the proportion of specific lipid classes showed.

Toxicity of sediment-associated tributyltin to infaunal invertebrates: Species comparison and the role of organic carbon

Abstract Experiments with three species of infaunal invertebrates (a polychaete, Armandia brevis and amphipods, Rhepoxynius abronius and Eohaustorius washingtonianus) with different modes of feeding gave a wide range in toxic response to sediment associated tributyltin (TBT), while exhibiting consistent lethal tissue residues. These studies showed that bioaccumulation and toxicity of sediment-associated TBT were strongly controlled by the organic carbon content of the sediment, which we concluded was primarily due to its influence on interstitial water (IW) concentrations of TBT. Major differences in the response to sediment-associated TBT were found between species, which was attributed to differences in their rates of uptake and elimination of this compound. Predictions for bioaccumulation and toxicity for each species based on these toxicokinetic rates were matched closely by observed values. Based on comparisons of water-only and IW exposures (when water and sediment concentrations of TBT were in equilibrium) and predictions made with toxicokinetic rates, the major route of uptake for each of the species tested appeared to be from dissolved TBT. We determined the mean (sd) organic-carbon normalized sediment-water partition coefficient (Koc) to be approximately 25 100 (5500) for TOC values ranging from 0.3 to 1.0%, which was five times higher than the reported Kow. Additionally, we determined the dissolved organic carbon—water partition coefficient (Kdoc) to be 1652, which was three fold lower than the Kow. The results also showed that the Koc could be influenced by infaunal organisms, presumably by reducing IW concentrations below predicted values, which raises questions about the environmental relevance of sediment bioassays using these organisms and the expected IW concentrations present in field sediments.

A method for analysis of butyltin species and measurement of butyltins in sediment and English sole livers from Puget Sound

Abstract A method for the determination of tetra-, tri-, di- and monobutyltin in marine sediments and in tissues from English sole was developed. The method utilized dichloromethane/tropolone extraction of the butyltins, derivatization with hexylmagnesium bromide, and a silica/alumina column cleanup prior to gas chromatographic/mass spectrometric (GC/MS) analysis. A number of quality assurance measures were incorporated in the method. Mean recoveries of the surrogate spike tripentyltin from sediment and tissue reference materials ranged from 96% to 110%. The method was applied to sediments and livers of English sole collected in Puget Sound, Washington state. Total butyltin concentrations in sediments ranged from 1000 ng/g were found in some sediments. Butyltins were also determined in livers from English sole captured at sites where sediments were contaminated with butyltins. Dibutyltin (at concentrations up to 870 ng/g dry weight as Sn) was the predominant butyltin species found in the livers.

Butyltin contamination of sediments and benthic fish from the East, Gulf and Pacific coasts of the United States.

Butyltin concentrations were determined in sediments, tissues and stomach contents of fish collected in 41 embayments on the East, Gulf and Pacific coasts of the U.S.A. between 1986 and 1991 as part of the National Oceanic and Atmospheric Administrations (NOAA) National Benthic Surveillance Project (NBSP). A total of 99 sediments, 108 fish liver samples from 11 fish species, and 10 composites of fish stomach contents were analyzed for tetrabutylin, tributylin, dibutylin and monobutylin. Tributyltin (TBT) was detected (i.e. > 10 ng/g) in 38 of the sediments samples analyzed and was generally the predominant bulytin present; concentrations of total butyltins ranged from 15 to 1600 ng/g wet weight. The highest concentrations were found in sediments from urban sites, especially sites on the West coast. Many of the fish liver and stomach contents samples also contained butyltins. Tributyltin represented 83 (7.1)% [mean (SEM); n=15], 64 (6.6)% (n=12) and 36 (7.8)% (n=12) of the total butyltins in livers from white croaker, winter flounder and Atlantic croaker, respectively, suggesting possible species differences in biotransformation of TBT. The concentrations of butyltins in stomach contents indicated that diet can be a significant route of exposure of fish to butyltins. Between 1986 and 1991 butyltin concentrations in sediments and fish generally appeared to be declining; however, no statistically significant temporal trends were observed at individual sites or for the sites overall.

Chemical contaminants in juvenile gray whales (Eschrichtius robustus) from a subsistence harvest in Arctic feeding grounds

Gray whales are coastal migratory baleen whales that are benthic feeders. Most of their feeding takes place in the northern Pacific Ocean with opportunistic feeding taking place during their migrations and residence on the breeding grounds. The concentrations of organochlorines and trace elements were determined in tissues and stomach contents of juvenile gray whales that were taken on their Arctic feeding grounds in the western Bering Sea during a Russian subsistence harvest. These concentrations were compared to previously published data for contaminants in gray whales that stranded along the west coast of the US during their northbound migration. Feeding in coastal waters during their migrations may present a risk of exposure to toxic chemicals in some regions. The mean concentration (standard error of the mean, SEM) of sigmaPCBs [1400 (130) ng/g, lipid weight] in the blubber of juvenile subsistence whales was significantly lower than the mean level [27,000 (11,000) ng/g, lipid weight] reported previously in juvenile gray whales that stranded in waters off the west coast of the US. Aluminum in stomach contents of the subsistence whales was high compared to other marine mammal species, which is consistent with the ingestion of sediment during feeding. Furthermore, the concentrations of potentially toxic chemicals in tissues were relatively low when compared to the concentrations in tissues of other marine mammals feeding at higher trophic levels. These chemical contaminant data for the subsistence gray whales substantially increase the information available for presumably healthy animals.

Estimation of levels of metabolites of aromatic hydrocarbons in fish tissues by HPLC/fluorescence analysis

Aromatic hydrocarbons (AHs) are extensively metabolized into oxidized products by fish and mammals. Some metabolites are more toxic than the parent AHs; however, currently there are no methods to screen tissues of fish or other marine species for the presence of AH metabolites. In the present study, a relatively rapid, semiquantitative method that combines enzymatic hydrolysis, methylene chloride extraction and hexane/potassium hydroxide partitioning with HPLC/fluorescence analysis, was developed for the estimation of the concentrations of polar fluorescent aromatic compounds (polar FACs; e.g., AH metabolites) in fish tissues. Liver and muscle from rock sole (Lepidopsetta bilineata) exposed to Prudhoe Bay crude oil in the laboratory were analyzed. Tissues from English sole (Parophrys vetulus) sampled at two sites (one nonurban reference and one AH-contaminated) in Puget Sound, WA were also analyzed. The concentrations of polar FACs in liver and muscle of PBCO-exposed rock sole were linearly proportional to dose. Also, in both species exposed to contaminants, the concentrations of polar FACs in liver were ∼15 times as great as those in muscle. Polar FACs, however, were not detected in muscle of English sole collected at either the contaminated or reference site, suggesting that polar FACs in naturally exposed animals may be present only at low concentrations unless exposed to high levels of contaminants such as AHs. Thus, the present method can detect, estimate and rank the relative concentrations of polar FACs (e.g., AH metabolites) in tissues, such as liver and muscle of fish. The method augments our ability to assess environmental exposure to potentially toxic contaminants such as AHs.

OIL EXPOSURE AND EFFECTS IN SUBTIDAL FISH FOLLOWING THE EXXON VALDEZ OIL SPILL

ABSTRACT The assessment of oil exposure and resulting biological effects in subtidal fish following marine oil spills is a rather challenging task, due to difficulty in sampling and a lack of metho...

Tributyltin Contamination Of Sediment And English Sole From Puget Sound

Sediment and English sole (Parophrys vetulus) from Puget Sound were analyzed for butyltins using a method developed in our laboratory. This method measures all four butyltin compounds in both sediment and tissues, and includes a number of quality control (QC) procedures. Total butyltin concentrations in sediment from five sites ranged from < 3.3 ng/g to 700 ng/g wet weight as tin. In English sole liver, total butyltins ranged from non-detectable to 250 ngfg wet weight as tin, while the greatest concentration found in muscle was 11 ng/g. A significant difference was observed between the butyltin profiles of muscle and liver. Although tributyltin was the predominant butyltin in muscle (and sediments), over 90% of the butyltins found in liver were present as dibutyltin. Because tributyltin is generally more toxic than dibutyltin, this difference in butyltin profile is potentially significant for fish exposed to butyltins.