Biomagnification of organochlorines along a Barents Sea food chain

To trace the biomagnification of organochlorines in marine food chains near Svalbard, which may lead to the high organochlorine concentrations in top predators from the area, we compared concentrations and patterns of organochlorines in selected taxa. The pelagic crustaceans, Calanus spp. (copepods), Thysanoessa spp. (euphausiids), Parathemisto libellula (amphipod), and the fish species, Boreogadus saida (polar cod) and Gadus morhua (cod) were selected to represent the lower trophic levels in the food web. Four seabird species were chosen at the higher trophic levels, Uria lomvia (Brünnich's guillemot), Cepphus grylle (black guillemot), Rissa tridactyla (black-legged kittiwake) and Larus hyperboreus (glaucous gull). We found low concentrations of the organochlorines sigma hexachlorocyclohexanes (sigma HCHs), hexachlorobenzene (HCB), sigma Chlordanes, sigma DDTs and sigma polychlorinated biphenyls (sigma PCBs) in crustaceans (11-50 ng g-1 lipid wt.) and fish (15-222 ng g-1 lipid wt.). In seabirds, the organochlorine concentrations biomagnified one to three orders of magnitude dependent on species and compound class. Glaucous gulls had the highest concentrations of all organochlorines. The organochlorine levels in all taxa except glaucous gull were comparable to those recorded in similar species in the Canadian Arctic. The organochlorine pattern changed from crustaceans and fish to seabirds. Moving up the food chain, the relative contribution of sigma HCHs, HCB and sigma Chlordanes decreased, and the relative contribution of sigma DDTs, sigma PCBs, persistent compounds and metabolites increased. The results reflected trophic transfer of organochlorines along the food chain as well as different elimination potentials due to direct diffusion in crustaceans and fish, and higher contaminant metabolic activity in seabirds.     

Organochlorine pesticides and hexachlorobenzene along the central coast of New South Wales: multi-scale distributions using the territorial damselfish Parma microlepis as an indicator.

Concentrations of 10 organochlorine pesticides and hexachlorobenzene (HCB) were determined in the territorial damselfish Parma microlepis at three urban locations and three reference locations centred on the Sydney region. Dieldrin, HCB and DDE were the most frequently detected organochlorines, occurring in 70-100% of samples collected. Alpha and gamma chlordane were also reasonably common and occurred in more than 30% of the samples. Each organochlorine compound investigated had a distinct spatial pattern of distribution. Related chemicals such as alpha and gamma chlordane, and DDT, DDE and DDD tended to have similar patterns of distribution. There were clear differences in patterns of distribution in organochlorines between urban and reference locations shown using non-parametric multivariate techniques. Relative variability of samples from urban locations was higher than at reference locations in 1993, but there was no consistent pattern of differences in the dispersions of samples among urban and reference locations in 1994. Age and condition indices (K) showed no association with total concentrations of organochlorine residues in fish. Significant, but weak associations were found between organochlorine residues and size, gonad somatic and liver somatic indices.     

Persistent organochlorine residues in northern fur seal from the Pacific coast of Japan since 1971

The present study was conducted to determine the residue levels of persistent organochlorines such as PCB homologues, DDT and its metabolites, and HCH isomers in the ventral blubber of female northern fur seal (Callorhinus ursinus) collected off Sanriku, the Pacific coast of northern Japan, since 1971. Among the organochlorines examined, the concentrations of PCBs and DDTs were found to be high in all samples. The residue levels of these two contaminants showed a drastic reduction following maturity and then a slight increase after the retirement from pregnancy/menopause. Temporal variation of PCB and DDT residues showed maximum levels around 1976 and then decreased, whereas HCH residue levels revealed a very slow declining pattern. Considering the concentrations and compositions of the residues, the northern fur seal is likely to be exposed to organochlorine contamination deriving from global terms. In this context, continuous contamination has been foreseen with regard to PCB and HCH residues. The pattern of organochlorine residues indicated that the northern fur seal has higher metabolic capacity than Dall's porpoise, while it is comparable to those of larga seal and Steller sea lion.     

Geographical distribution of persistent organochlorines in air, water and sediments from Asia and Oceania, and their implications for global redistribution from lower latitudes

Persistent organochlorines in air, river water and sediment samples were analysed from eastern and southern Asia (India, Thailand, Vietnam, Malaysia, Indonesia) and Oceania (Papua New Guinea and Solomon Islands) to elucidate their geographical distribution in tropical environment. The concentrations of organochlorines in these abiotic samples collected from Taiwan, Japan and Australia were also monitored for comparison. Atmospheric and hydrospheric concentrations of HCHs (hexachlorocyclohexanes) and DDTs (DDT and its metabolites) in the tropical developing countries were apparently higher than those observed in the developed nations, suggesting extensive usage of these chemicals in the lower latitudes. CHLs (chlordane compounds) and PCBs (polychlorinated biphenyls) were also occasionally observed at higher levels in the tropics, implying that their usage area is also expanding southward. Distribution patterns of organochlorines in sediments showed smaller spatial variations on global terms, indicating that the chemicals released in the tropical environment are dispersed rapidly through air and water and retained less in sediments. The ratios of organochlorine concentrations in sediment and water phases were positively correlated with the latitude of sampling, suggesting that persistent and semivolatile compounds discharged in the tropics tend to be redistributed on a global scale.     

Comparison of residue levels of persistent organochlorine compounds in butter from Spain and from other European countries

Commercially available butter from Spain (n = 36) and from other European countries (n = 20) has been analyzed by high resolution gas chromatography with an electron capture detector for organochlorine contaminants. The results showed that both groups of samples have a similar pattern of these pollutants, but in all cases where significant differences in concentrations were found, Spanish samples presented higher values. This was especially notable for lindane (median values 11.6 vs. 3.0 ng/g wet weight), hexachlorobenzene (6.4 vs. 0.5) and beta-hexachlorocyclohexane (3.1 vs. 1.2). Total PCBs showed no differences (5.4 vs. 6.6), but detailed analysis of congener composition indicated a higher presence in Spanish samples of the most persistent chlorinated PCBs. No sample presented levels of concern for any single organochlorine compound. It is interesting to note that consumption of butter in Spain is low so, although levels of organochlorines are higher than those found in other countries, consumers are less exposed through this foodstuff than in other European countries. These results also confirm the fact that environmental pollution by organochlorines is more important in Spain than in the rest of Europe.     

Comparison of residue levels of persistent organochlorine compounds in butter from Spain and from other European countries

Abstract

Commercially available butter from Spain (n=36) and from other European countries (n=20) has been analyzed by high resolution gas chromatography with an electron capture detector for organochlorine contaminants. The results showed that both groups of samples have a similar pattern of these pollutants, but in all cases where significant differences in concentrations were found, Spanish samples presented higher values. This was especially notable for lindane (median values 11.6 vs. 3.0 ng/g wet weight), hexachlorobenzene (6.4 vs. 0.5) and ß‐hexachlorocyclohexane (3.1 vs. 1.2). Total PCBs showed no differences (5.4 vs. 6.6), but detailed analysis of congener composition indicated a higher presence in Spanish samples of the most persistent chlorinated PCBs. No sample presented levels of concern for any single organochlorine compound. It is interesting to note that consumption of butter in Spain is low so, although levels of organochlorines are higher than those found in other countries, consumers are less exposed through this foodstuff than in other European countries. These results also confirm the fact that environmental pollution by organochlorines is more important in Spain than in the rest of Europe.     

Organochlorine pesticide and polychlorinated biphenyl residues in foodstuffs from Bangkok, Thailand

Raw foodstuffs collected from Bangkok, Thailand, were analysed for the presence of PCBs, DDTs, HCHs (BHCs). HCB, aldrin, dieldrin, heptachlor and heptachlor epoxide. Residues of PCBs and organochlorine pesticides were detected in all the samples analysed. Concentrations of PCBs did not reach the tolerance limit set forth by the US Food and Drug Administration (FDA). The concentrations of SigmaHCH were higher than those of SigmaDDT in all the farm products while the levels of SigmaDDT were greater in fishes including fish flakes and fishmeal. Meat samples recorded higher concentrations of SigmaDDT and dieldrin than SigmaHCH. Comparing the levels of organochlorines in foodstuffs from Bangkok, considerable levels of aldrin and dieldrin indicate the need for concern from the food safety point of view because of their much higher toxicity than DDT and other organochlorines. However, the levels did not exceed the Maximum Residue Limit (MRL) recommended by FAO/WHO. Food contamination by HCB, heptachlor and heptachlor epoxide is comparatively lower.     

Accumulation features of persistent organochlorines in resident and migratory birds from Asia

Concentrations of organochlorine contaminants including polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs), hexachlorobenzene (HCB) were determined in the resident and migratory birds, which were collected from India, Japan, Philippines, Russia (Lake Baikal) and Vietnam. Accumulation patterns of organochlorine concentrations in resident birds suggested that the predominant contaminants of each country were as follows: Japan--PCBs Philippines--PCBs and CHLs, India--HCHs and DDTs, Vietnam--DDTs, and Lake Baikal--PCBs and DDTs. The migratory birds from Philippines and Vietnam retained mostly the highest concentrations of DDTs among the organochlorines analyzed, indicating the presence of stopover and breeding grounds of those birds in China and Russia. On the other hand, migratory birds from India and Lake Baikal showed different patterns of organochlorine residues, reflecting that each species has inherent migratory routes and thus has exposure to different contaminants. Species which have breeding grounds around the Red Sea and Persian Gulf showed high levels of PCBs, indicating the presence of areas heavily polluted by PCBs in the Middle East.     

Organochlorine and organotin compounds in Caspian seals (Phoca caspica) collected during an unusual mortality event in the Caspian Sea in 2000

Polychlorinated biphenyls (PCBs), organochlorine pesticides and organotin compounds were determined in the blubber and liver of Caspian seals (Phoca caspica) found stranded on the coast of the Caspian Sea during an outbreak of canine distemper virus (CDV) in 2000. Among organochlorines analyzed, DDTs were the most dominant contaminants with concentrations ranging from 6.3 to 470 microg/g on a lipid-weight basis. Caspian seals collected in 2000 during the epizootic had higher concentrations of organochlorines than healthy individuals sampled in 1998. However, the blubber layer was generally thinner in the seals collected in 2000 than those in the previous surveys. Although compositions of organochlorine pesticides in seals suggested that the contamination status in the Caspian Sea is improving, the levels found in Caspian seals in 2000 were comparable to those in other marine mammals that have suffered from epizootics. This implies that the present status of contamination found in Caspian seals poses a risk of immunosuppression. Concentrations of butyltin compounds in livers of seals ranged from 0.49 to 17 ng/g on a wet-weight basis and octyltin compounds were below limit of detection in all the samples analyzed, suggesting less contamination by organotin compounds in the Caspian Sea.     

Pesticide residues in freshwater and marine zooplankton: a review

A review of the scientific literature on pesticide residues in freshwater and marine zooplankton indicates that despite the great number of pesticides in current use, only residues of the persistent organochlorine insecticides, many of which have been restricted or removed from general use in North America, have been determined. Much of this information is outdated. In addition, with the exception of the Great Lakes on which limited information is available, reports on residues in freshwater zooplankton are rare. Information on residues of the newer, less persistent but heavily used pesticides is lacking. As an alternative to field sampling and chemical analysis of endemic populations of zooplankton, scientists have modeled the bioaccumulation of pesticides in zooplankton using either laboratory microcosms or mathematical equations. However, the extent and importance of trophic transfer to higher food levels through this intermediary group of organisms is still controversial. In addition, the relationship between accumulation of pesticides and toxicity to zooplankton remains unresolved.     

Organochlorine contaminants in eggs of the yellow-legged gull (Larus cachinnans michahellis) in the North Eastern Mediterranean: is this gull a suitable biomonitor for the region?

Levels of eight PCB congeners and thirteen organochlorine pesticides were measured in eggs sampled at four yellow-legged gull colonies from the Aegean Sea (NorthEastern Mediterranean) in 1997. There were no significant differences among colony areas in the median concentrations in any of the pollutants whereas cluster analyses did not generally reveal reasonable pollution patterns. The maximum concentrations of four congeners were found at Kinaros colony and of nine compounds were found at Lipsos colony. Fingerprints in both groups were similar in all areas. Of PCBs, congener 28, 118, 138, 180 and of pesticides beta-BHC and 2,4'-DDD were prominently dominant suggesting a particular pollution pattern in this region. Statistically significant correlations were found between most of the higher PCBs in all areas studied. The DDT metabolites correlated mostly with other OCs. We suggest that regional pollution by both groups is not adequately reflected in the eggs of this gull probably due to its extensive scavenging habits and, though information is needed from more colonies, it seems to be a poor biomonitor for organochlorines in this region.     

Organochlorine pesticides and hexachlorobenzene in tissues of fish and invertebrates caught near a sewage outfall

Concentrations of organochlorine pesticides and hexachlorobenzene (HCB) were determined in 16 fish, 1 mollusc and 1 crustacean species living near a cliff-face sewage outfall. For the 15 organochlorine compounds scanned, HCB, chlordane, dieldrin and SigmaDDT were recorded in highest concentrations. There was considerable variation in concentrations between muscle and liver and between species. Livers had higher concentrations of organochlorines and a higher percentage lipid than muscle. The highest concentrations were recorded in livers of the elasmobranch and tetraodontiform fishes. Organochlorines were only recorded at low concentrations in muscle, often at or near detection limits. No organochlorines were detected in the two invertebrate species.     

Organochlorine contaminants in the estuarine and coastal marine environments of the Fiji Islands

No information has been published on the presence of organochlorine pesticides and polychlorinated biphenyls in the Fiji Islands. This paper reports the first data on the concentration of a range of organochlorine compounds in sediments and shellfish in the estuarine and coastal marine environment around Fiji. Twenty-three sediment and two shellfish samples were analysed for 22 pesticides and related residues, and PCBs. While a significant number of organochlorines (20 pesticide related species and PCBs) was detected, the concentrations were generally very low (< 10 ng g), indicative of a relatively 'less contaminated' marine environment. Relatively high concentrations were observed only near the two major ports (Suva and Lautoka), with Suva harbour samples having the largest number of detectable species and the largest total concentrations of organochlorines (up to 91 ng g). No PCBs were detected in areas away from major industrial centres. The variations in the concentrations found, and the possible sources and movement of the organochlorine contaminants are discussed.     

Disposition of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in two Norwegian epibenthic marine food webs

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are a group of halogenated hydrocarbons, comprising 210 different, theoretically possible congeners. They are relatively hydrophobic and persistent to biodegradation, thereby rendering them subject to bioaccumulation. This study was conducted in Frierfjord and Eidangerfjord in the Grenland fjord system, Norway, heavily polluted by PCDD/PCDF discharges from the magnesium production at Herøya from 1951 to 2001. Pooled samples of surface-sediments and the following organisms were collected for the Frierfjord and Eidangerfjord study areas: common shrimp (Crangon crangon), polychaetes (mainly Nereis diversicolor), shore crab (Carcinus maenas), cod (Gadus morhua), flounder (Platichthys flesus), trout (Salmo trutta), herring (Clupea harengus), benthic amphipods and zooplankton. Concentrations of 2,3,7,8-PCDD/Fs were quantified in pooled samples for all species. The relative abundances of stable isotopes of nitrogen (δ¹⁵N) were evaluated in the organisms as a measure of chemically-derived trophic level. Contrary to earlier studies on other persistent organochlorines, it was found that the concentrations of PCDD/Fs declined with increasing trophic level. Principal Component Analysis (PCA) also showed differences between species in the pattern of PCDD/Fs. Higher chlorinated congeners constituted lower percentages of the PCDD/F-concentrations higher in the food chain as compared to lower trophic levels. In general, congener patterns did not differ between fjords. Infauna (polychaetes) and zooplankton had congener patterns most similar to the pollution source. The results indicate lower accumulation of higher chlorinated congeners in species at higher trophic levels (fish), presumably due to low membrane permeability (high molecular size) and possibly slow transport through intestinal aqueous phases because of low aqueous solubility.     

Habitat-specific bioaccumulation of methylmercury in invertebrates of small mid-latitude lakes in North America

We examined habitat-specific bioaccumulation of methylmercury (MeHg) in aquatic food webs by comparing concentrations in pelagic zooplankton to those in littoral macroinvertebrates from 52 mid-latitude lakes in North America. Invertebrate MeHg concentrations were primarily correlated with water pH, and after controlling for this influence, pelagic zooplankton had significantly higher MeHg concentrations than littoral primary consumers but lower MeHg than littoral secondary consumers. Littoral primary consumers and pelagic zooplankton are two dominant prey for fish, and greater MeHg in zooplankton is likely sufficient to increase bioaccumulation in pelagic feeders. Intensive sampling of 8 lakes indicated that habitat-specific bioaccumulation in invertebrates (of similar trophic level) may result from spatial variation in aqueous MeHg concentration or from more efficient uptake of aqueous MeHg into the pelagic food web. Our findings demonstrate that littoral-pelagic differences in MeHg bioaccumulation are widespread in small mid-latitude lakes.     

Environmental contaminants and reproductive success of great blue herons Ardea herodias in British Columbia, 1986-1987

In 1986, eggs were collected and productivity estimated at four great blue heron (Ardea herodias) colonies on the coast of British Columbia. Polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were present in all eggs in a qualitatively similar pattern among colonies. PCDD levels were significantly elevated at a colony near a kraft pulp mill at Crofton on Vancouver Island, although there was no correlation between the number of young raised in a nest and levels of either PCDDs, PCDFs, PCBs, organochlorine pesticides or mercury. In 1987, heron productivity was normal at three colonies, while the colony at Crofton failed to raise any young. A normal complement of eggs were apparently laid in about 57 nests, but during incubation they were destroyed and the broken eggshells were found in and beneath the nests. Analysis of eggs salvaged from nests showed that 2378-TCDD levels were about three times higher in 1987 than in 1986. At a colony in Vancouver, 2378-TCDF levels were significantly higher in 1987 than 1986 eggs. Levels of organochlorine pesticides and total mercury in eggs were generally low; highest residue levels were found in two mainland colonies, particularly at one adjacent to an agricultural area. Total PCB levels were low and did not differ significantly among locations. Analysis of PCB congener ratios indicated different sources of PCBs. Regurgitated prey samples collected in 1986 from four locations had generally low levels of PCDD, PCDF, mercury, lead and cadmium contamination.     

Long-term trends and sources of organochlorine contamination in Canadian tundra Peregrine Falcons, Falco peregrinus tundrius

Levels of eggshell thinning, and organochlorine residues in egg contents, blood plasma of adults and juveniles, tissue samples, and prey species were determined for a population of migratory Peregrine Falcons (Falco peregrinus tundrius) breeding in the Canadian Arctic. Temporal trends were assessed by comparing data collected during 1991-1994, with data from 1982-1986, for the same population. Shells (n=54) from 1991-1994 averaged 15% thinner than eggs produced prior to the introduction of DDT. No improvement in shell thickness was detected between decades. Mean DDE residue levels in eggs showed a decline from 7.6 mg kg (1982-1986) to 4.5 mg kg (1991-1994), but there was no significant change in SigmaPCB residues. Moreover, the proportion of clutches with eggs exceeding critical SigmaPCB, DDE, and dieldrin residue levels (10%) did not change between decades. Relative to Greenland and Alaskan populations, F. p. tundrius at Rankin Inlet show high levels of organochlorine contamination and little reduction in residues over the last decade. These Tundra Peregrines continue to be exposed to organochlorines in Latin America; however, results also link relatively high levels in the study population with waterfowl species that do not leave Canada in winter.     

Heavy metals in zooplankton from the Southern Baltic

Samples of zooplankton and suspended matter were collected using a Bongo net (0.33/0.50 mm mesh net), and Nucleopore filters, respectively, from the Southern Baltic off Poland. Major classes of zooplankton, and selected heavy metals (Fe, Co, Ni, Mn, Pb, Cd, Cu, Zn, Cr) were determined in the collected samples. Concentrations of heavy metals in zooplankton were corrected for metals contributed by particulate matter adhering to zooplankton organisms. Heavy metals levels measured in nearshore samples (Bay of Gdańsk, Pomeranian Bay) were higher than those in the samples from the open sea. The only exception was cadmium exhibiting larger concentrations in the offshore as compared to the nearshore samples (0.8 vs. 1.3 microg/g d.w.). This was attributed to decreased concentrations, of both dissolved and particulate cadmium, caused by algal bloom. Larger concentrations of heavy metals in the Bay of Gdańsk in comparison with the Pomeranian Bay (e.g. Cd-1.3 vs. 0.8 microg/g, Cu-20.5 vs. 8.3 microg/g, Pb-12.9 vs. 1.2 microg/g, Cr-12.4 vs. 1.4 microg/g) were attributed to the direct discharge of the Vistula river to the Bay of Gdańsk, while the Pomeranian Bay receives the Odra river runoff indirectly, via the Szczecin Lagoon. The nonlinear estimation of the data set was used to evaluate concentrations of heavy metals in Copepoda and Cladocera. Copepoda proved to be enriched with heavy metals in comparison with Cladocera.     

Organochlorine contaminants in northeast Atlantic minke whales (Balaenoptera acutorostrata)

Blubber samples of 72 minke whales (Balaenoptera acutorostrata) were obtained from the northeast Atlantic in July and August 1992, and evaluated for organochlorine contamination. The following organochlorines were determined: the industrial chemicals PCBs (polychlorinated biphenyls), and the organochlorine pesticides DDTs (dichlorodiphenyltrichloroethanes), HCHs (hexachlorocyclohexaneb), HCB (hexachlorobenzene) and CHLs (chlordanes). The concentrations of SigmaPCB (sum of concentrations of 18 PCB congeners) and SigmaDDT (sum of concentrations of p,p'-DDT, p,p'-DDE, p,p'-DDD, o,p'-DDT and o,p'-DDD) ranged from 0.6-20.8 and 0.5-14.8 microg g(-1) lipid weight, with mean concentrations at 3.8 and 2.5 microg g(-1) lipid weight, respectively. The mean concentrations of HCB, the chlordane metabolites oxychlordane, cis-chlordane and trans-nonachlor, and the HCH isomers (alpha-, beta- and gamma-HCH) were all < 1 microg g(-1) lipid weight. Significantly higher concentrations of the three major pollutants (SigmaPCB, SigmaDDT and SigmaCHL) were found in mature males as compared to mature females and juveniles of both sexes. No such relationship was found for SigmaHCH and HCB. Stomach contents of northeast Atlantic minke whales indicate considerable heterogeneity in the diet when comparing different years, seasons and geographical areas. However, without knowing more about the minke whale migration pattern, or possible geographical segregation with age and sex, the interchemical variation of organochlorines between sampling areas may not reflect true geographical differences.