Mercury in Feathers of Audouin's Gull (Larus audouinii) Chicks from Northeastern Mediterranean Colonies

Feathers of Audouin's gull chicks from three Aegean island areas (north Dodecanese, Cyclades, Kythera) Greece, were sampled in 1997 and 1998 and analyzed for mercury. Mean concentrations varied from 0.94 μg/g (Lipsos, Dodecanese, 1998) to 2.14 μg/g (Paros, Cyclades, 1998). Significant differences between years occurred in some regions (Lipsos, Fourni) but not in others (Paros). Within each year, especially in 1998, mean mercury concentrations differed among colonies. Results did not support the prediction that mercury levels would be higher in the north Dodecanese area due to the proximity of the polluted Menderes delta. There was no relationship between estimated chick age and feather mercury contents (r =−0.04, NS). Detected mercury levels do not seem to pose any toxic hazard to the Aegean Audouin's gull populations. However, the ease of sampling from gulls indicates that they may be a useful biomonitor of mercury contamination in this region. Received: 2 November 1999/Accepted: 10 March 2000     

Inter- and Intraclutch Variability in Heavy Metals and Selenium Levels in Audouin's Gull Eggs from the Ebro Delta, Spain

Heavy metal (Zn, Cu, Mn, Cd, Pb, Hg) and Se concentrations were analyzed in 57 Audouin's gull (Larus audouinii) eggs belonging to different clutch sizes. Inter- and intraclutch variability in metal concentrations was investigated as a potential source of bias in the assessment of pollution levels. Moreover, we analyzed the relationship between metal levels in the shell and in the contents, to evaluate the reliability of museum eggshells as indicators of historical changes of these pollutants. An outstanding female effect and/or a laying order effect underlies egg Hg levels; the fact that eggs in a clutch are not independent observations needs to be taken into account both when designing sampling strategies and when performing any analysis or interpretation of the results. The relationship between Hg in shells and contents is not sufficiently accurate to allow the use of egg-shell concentration as a reliable predictor of egg-contents concentration. However, if changes in the ecosystems are large enough it could be used to trace gross historical trends of these pollutants. Received: 10 June 1996/Revised: 28 October 1996     

Mercury Concentration in 3 Species of Gulls, Larus ridibundus, Larus minutus, Larus canus, From South Coast of the Caspian Sea, Iran

In this study, the mercury concentrations of liver, breast feathers and tail feathers in three species of Gull; Black-headed Gull (Larus ridibundus), Common Gull (Larus canus) and Little Gull (Larus minutus) from the South coast of the Caspian Sea in Iran were assayed. Mercury accumulation in liver, breast feathers and tail feathers of species were 1.69–3.16, 2.88–7.18 and 2.09–5.66 mg/kg, respectively. Mercury concentration hierarchy in tissues we tested was as follows: breast feather > tail feather > and liver. We found that despite its small size, Little Gull had highest (3.85–8.05 mg/kg) and Common Gull lowest (1.69–2.88 mg/kg) level of Hg in their bodies. An inverse relationship between body size and Hg levels in these Gulls was detected. Mercury in Little Gull and Black-headed Gull exceeded the 5 ppm threshold for adverse effect.     

Age Differences in Metals in the Blood of Herring (Larus argentatus) and Franklin's (Larus pipixcan) Gulls

Concentrations of heavy metals and selenium were measured in the blood of adult and young herring (Larus argentatus) and Franklin's (Larus pipixcan) gulls collected during the same breeding season in colonies in the New York Bight and in northwestern Minnesota, respectively. Concentrations were expected to be higher in young herring gulls collected in an urban, industrialized area, compared to young Franklin's gulls collected in a relatively pristine prairie marsh. Exposure is similar for the fledgling and adult gulls because by the time the blood of young gulls is drawn both adults and young have been eating foods from the surrounding region for two months; leading to the prediction that metal levels should be similar in adults and young. However, young Franklin's gulls had significantly higher levels of arsenic, cadmium, and manganese than adults; adults had significantly higher levels of mercury and selenium. Young herring gulls had significantly higher concentrations of arsenic and selenium, but lower levels of lead than adult herring gulls. Interspecific comparisons indicated that young Franklin's gulls had significantly higher levels of cadmium than young herring gulls, and adult Franklin's gulls had higher levels of selenium and chromium than adult herring gulls, but for all other comparisons herring gulls had higher levels of metals in their blood. Young herring gulls chicks had higher arsenic, manganese, and selenium levels and lower cadmium and lead levels in 1993 than in 1994. Overall, the levels in the two species were usually within an order of magnitude. Received: 11 November 1996/Accepted: 16 April 1997     

Spatial Patterns in a Bioindicator: Heavy Metal and Selenium Concentration in Eggs of Herring Gulls (Larus argentatus) in the New York Bight

Concentrations of selenium and five heavy metals (lead, cadmium, mercury, chromium, and manganese) in the eggs of herring gulls (Larus argentatus) were studied at six breeding colonies in the New York Bight to detect locational differences and to explore their use as a bioindicator of point source or nonpoint source pollution. The herring gull is widespread in North America, Europe, and Asia, and has urban-adapted counterparts in the southern hemisphere as well. We anticipated that the chromium contamination at Jersey City and high levels of manganese in industrial releases to the Passaic River would be reflected in the nearest colony (Shooter's Island), and that lead contamination from bridge remediation would be apparent in the Jamaica Bay colonies. There were significant locational differences in all metal levels, although the patterns were not the same for all metals. Shooter's Island in Newark Bay ranked first or second for five of the elements, but inexplicably had the lowest mercury level. Cadmium levels were highest at Canarsie Pol in Jamaica Bay, but mercury levels were highest at the relatively isolated Lavallette colony in northern Barnegat Bay. Chromium and manganese levels were indeed highest at Shooter's Island, but the lead levels in Jamaica Bay were only intermediate. We predicted that the essential trace elements, manganese, chromium, and selenium, which are known to be present at relatively high concentrations in various animal species, would have relatively low coefficients of variation, reflecting homeostatic mechanisms. This was confirmed. In conclusion, herring gull egg contents can be used to monitor metal concentrations at nearby colonies to indicate areas of concern for particular metals. They may confirm suspected associations or identify hitherto unsuspected problems. Received: 22 June 1996/Accepted: 14 October 1996     

Isolation, Cryopreservation, and Mitogenesis of Peripheral Blood Lymphocytes from Chickens (Gallus domesticus) and Wild Herring Gulls (Larus argentatus)

Monitoring the toxicity of environmental contaminants on the physiologic function of wild birds often includes measures of immune function. The purpose of this study was to apply methods of isolation, cryopreservation, and cell culture of chicken lymphocytes to blood samples from herring gulls, which are a sentinel species for biomonitoring studies in the Great Lakes and northern North America. Slow-spin centrifugation and density gradient isolation of lymphocytes were compared using chicken blood. Significant thrombocyte contamination of density gradient isolated samples (40% to 77% thrombocytes) led to the use of slow-spin centrifugation (2% thrombocytes) for blood from herring gulls. Cryopreserved blood samples were collected from adult and prefledgling herring gulls at sites of low environmental contamination around the Great Lakes and the Bay of Fundy between 1999 and 2002. Cryopreservation decreased the viability of lymphocytes from wild birds, but a high proportion of samples yielded enough live lymphocytes to assess function in culture. Cryopreserved lymphocytes from herring gulls proliferated in response to phytohemagglutinin (PHA), concanavalin-A, phorbol myristate acetate (PMA), PHA plus PMA, and lipopolysaccharide stimulation. Weber and Roswell Park Memorial Institute medium (RPMI) 1640 media were compared for culture of lymphocytes. Weber medium better supported chicken B-lymphocyte proliferation than RPMI 1640 and supported chicken T-lymphocyte proliferation of a similar magnitude as RPMI. Proliferation responses for lymphocytes from prefledgling herring gulls were stronger in Weber medium than RPMI medium, especially for PHA, for which there was no stimulation in RPMI. Proliferation responses of lymphocytes from adult herring gulls were up to twofold greater than that for prefledgling herring gulls. The magnitudes of proliferation responses were similar to that for chicken lymphocytes. These methods have subsequently proven useful in ecotoxicology studies that involve species in remote locations.     

Geographic Variation in Hematological Variables in Adult and Prefledgling Herring Gulls (Larus argentatus) and Possible Associations with Organochlorine Exposure

The objectives of this study were (1) to describe variation in hematological values found in adult and prefledgling herring gulls (Larus argentatus) over a large geographic area, (2) to investigate relationships between hematological variables and other physiological indices, and (3) to examine potential associations between exposure to organochlorines and hematological variables. During 1991–93, we sampled 160 breeding adult gulls from 13 colonies and 101 4-week-old gulls from 11 colonies. All colonies were in the Great Lakes ecosystem, except for two colonies on Lake Winnipeg and the Atlantic coast. The hematological values measured in this study were similar to published values for herring gulls and related species. Significant intersite differences were found in hematological variables. Sex had little or no influence on leukocyte variables. Adults had lower total leukocyte counts and higher heterophil to lymphocyte ratios than chicks. PCV was lower in adult females than males. In adults, total leukocyte and total heterophil numbers were negatively associated with liver activity of ethoxyresorufin-O-deethylase (EROD) and concentrations of highly carboxylated porphyrins (HCPs), two biomarkers of organochlorine exposure. Total leukocyte and total heterophil numbers were positively associated with liver concentrations of DDE (1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene), and total lymphocytes were associated positively with PCB (polychlorinated biphenyl) and HCP concentrations. The heterophil to lymphocyte ratio was negatively associated with liver EROD activity and HCPs. In chicks, there was a positive association between the heterophil to lymphocyte ratio and HG-TEQs (dioxin toxicity equivalents calculated using herring gull–specific equivalency factors). PCV was associated with some measures of contaminant exposure in adults and chicks. Additional research is needed to elucidate causal relationships between hematological indices and such factors as contaminants, disease, and nutrition. Received: 11 March 1999/Accepted: 26 August 1999     

Mercury levels in Bonaparte's gulls (Larus Philadelphia) during autumn molt in the Quoddy region,New Brunswick,Canada

No significant between sex differences were detected in Hg concentrations in primary feathers, pectoral muscle, brain, liver, and kidney tissues of fall migrating juvenile and second-year Bonaparte's gulls (Larus Philadelphia) collected in the Quoddy region. Adults showed sexual differences only in the first 5 primary feathers, and in muscle, kidney and brain. Differences in Hg concentrations among age groups were reflected in the primary feathers and body tissues, but as the molt progressed, Hg concentrations decreased as they converged toward a minimum asymptotic Hg level for each tissue. This suggests that the body burden of Hg was reduced through its redistribution from the body tissues into the growing feathers. Mercury concentrations in premolt head feathers (pre-egg-laying) did not vary significantly between adult females and males, whereas Hg concentrations in postmolt feathers (post-egg-laying) were significantly lower in females, suggesting that egg-laying was also a route for Hg elimination. After the completion of the molt, the new feathers contained most of the body burden of Hg (93.0% in adults).     

Trace Element Concentrations (Mercury, Cadmium, Copper, Zinc, Lead, Aluminium, Nickel, Arsenic, and Selenium) in Some Aquatic Birds of the Southwest Atlantic Coast of France

Trace elements (mercury [Hg], cadmium [Cd], copper [Cu], zinc [Zn], lead [Pb], aluminium [Al], nickel [Ni], arsenic [As], and selenium [Se]) were investigated using inductively coupled plasma–mass spectrometry in liver, kidney, muscle, and feather of aquatic birds wintering or inhabiting the wetlands situated on the Southwest Atlantic coast of France. A majority of greylag geese, red knots, and grey plovers were collected from among hunter-shot animals. The relation between residue concentrations, age (juvenile vs. adult), and sex was investigated. Trace elements were lower than threshold levels of toxicity, except for Pb. Greylag geese sampled could be considered Pb-poisoned. These consequential levels of contamination could be the result of the ingestion of Pb-shot from ammunition used in hunting areas they crossed during migration. Cd accumulation increased with age, whereas Pb levels in feathers were lower in adult birds in connection with moulting. As was influenced by sex. Female birds displayed higher concentrations in liver and feathers than did male birds.     

Mercury Concentrations in Invasive Burmese Pythons (Python bivitattus) of Southwest Florida

Bulletin of Environmental Contamination and Toxicology - We determined mercury (Hg) concentrations in various tissues of Burmese pythons (Python bivitattus; n = 227) caught in southwest...     

Mercury distribution in the soil-plant-air system at the Wanshan mercury mining district in Guizhou, Southwest China

The level of mercury bioaccumulation in wild plants; the distribution of bioavailable Hg, elemental Hg, and total Hg in soil; and the concentration of total gaseous Hg (TGM) in ambient air was studied at three different mining sites (SiKeng [SK], WuKeng [WK], and GouXi [GX]) in the Wanshan mercury mining district of China. Results of the present study showed that the distribution of soil total Hg, elemental Hg, bioavailable Hg, and TGM varies across the three mining sites. Higher soil total Hg (29.4-1,972.3 mg/kg) and elemental Hg (19.03-443.8 mg/kg) concentrations were recorded for plots SK and WK than for plot GX. Bioavailable Hg was lower at plot SK and GX (SK, 3-12 ng/g; GX, 9-14 ng/g) than at plot WK (11-1,063 ng/g), although the TGM concentration in the ambient air was significantly higher for plot GX (52,723 ng/m(3) ) relative to WK (106 ng/m(3) ) and SK (43 ng/m(3)). Mercury in sampled herbage was elevated and ranged from 0.8 to 4.75 mg/kg (SK), from 2.17 to 34.38 mg/kg (WK), and from 47.45 to 136.5 mg/kg (GX). Many of the sampled plants are used as fodder or for medicinal purposes. High shoot Hg concentrations may therefore pose an unacceptable human health risk. Statistical analysis of the recorded data showed that the Hg concentration in plant shoots was positively correlated with TGM and that the Hg concentration in roots was positively correlated with the bioavailable Hg concentration in the soil. The bioaccumulation factor (BAF) in the present study was defined with reference to the concentration of bioavailable Hg in the soil (Hg([root]) /Hg([bioavail])). Three plant species, Macleaya cordata L., Achillea millefolium L., and Pteris vittata L., showed enhanced accumulation of Hg and therefore may have potential for use in the phytoremediation of soils of the Wanshan mining area.     

Levels of Cadmium, Mercury, and Lead in Magellanic Penguins (Spheniscus magellanicus) Stranded on the Brazilian Coast

Cadmium (Cd), mercury (Hg), and lead (Pb) were determined in samples of liver and breast muscles of first-year Magellanic penguins (Spheniscus magellanicus), from two different areas on the Brazilian coast, 35 on the Rio de Janeiro coast and 12 on the Rio Grande do Sul coast. In both areas, Cd concentrations in muscle samples were <0.025 μg/g. However, the Cd and Hg concentrations found in liver and Hg concentrations found in muscle showed a significant difference between the two regions. The geometric mean of the concentrations was higher in the specimens from Rio de Janeiro (Cd—6.8 μg/g; Hg—liver, 1.6 μg/g, and muscle, 0.4 μg/g wet weight) than in those from Rio Grande do Sul (Cd—2.3 μg/g; Hg—liver, 0.9 μg/g, and muscle, 0.1 μg/g wet weight). The site differences could be related to differences in diet influenced by geographic factors. Brazil’s southeastern coast is highly urbanized, and its coastal waters are contaminated by the waste of agricultural and industrial activities. There is a lack of information on the levels of heavy metals in S. magellanicus, however, their wide distribution and top position in the trophic chain make the use of stranded specimens an attractive source of information for monitoring heavy metals in the South Atlantic coast.     

Levels and Variability of Metals in Soils of the Province of Golestan (Iran)

Studying the concentration distribution of metals is necessary for soil pollution monitoring and maintaining environmental quality. To date, very little large-scale research has been performed to investigate metal contamination in developing countries. In this study, the content and spatial distributions of five metals (cadmium [Cd], copper [Cu], nickel [Ni], lead [Pb], and zinc [Zn]) were quantified based on 346 topsoil samples from 12 districts in the province of Golestan (northeast [NE] Iran). The concentration levels (mg/kg) of Cd, Cu, Pb, Ni and Zn varied from 0.02 to 0.36, 9.3 to 93.7, 6.8 to 44, 9.5 to 85.35, and 25 to 417.4, respectively. The average concentrations (mg/kg) obtained were as follows: Cd 0.12 ± 0.07, Cu 23.9 ± 9.07, Ni 34.88 ± 11.59, Pb 15.42 ± 5.81 and Zn 82.08 ± 30.87. Significant differences in the distribution of trace elements among districts were detected. The AzadShahr and BandarGaz districts displayed the highest metal concentrations. Greater metal values were obtained in the central, south, west, and NE areas, although Zn concentration was also high to the north of the province. Values of contamination factor and contamination degree indicated that the metal pollution level was on the order of Zn > Cd > Pb > Cu > Ni and that all of the metals belonged to a low or moderate pollution category. Ni and Cu levels derived from natural sources, whereas Cd, Pb, and Zn derived from anthropogenic activities with greater mean concentrations than reference concentrations.