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Biological effects of gold mine tailings on the intertidal marine environment in Nova Scotia,Canada 总被引：1，自引：0，他引：1
From 1861 to the 1940s, gold was produced from 64 mining districts in Nova Scotia, where mercury amalgamation was the dominant method for the extraction of gold from ore until the 1880s. As a result, wastes (tailings) from the milling process were contaminated by mercury and were high in naturally occurring arsenic. In 2004 and 2005, sediments, water and mollusc tissues were collected from 29 sampling stations at nine former gold mining areas along the Atlantic coastline and were analysed for arsenic and mercury. The resulting data were compared with environmental quality guidelines. Samples indicated high potential risk of adverse effects in the intertidal environments of Seal Harbour, Wine Harbour and Harrigan Cove. Arsenic in Seal Harbour was bioavailable, resulting in high concentrations of arsenic in soft-shell clam tissues. Mercury concentrations in tissues were below guidelines. This paper presents results of the sampling programs and implications of these findings. 相似文献
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The present study established an experimental marine food chain of three levels (microalgae → zooplankton → fish) to investigate the effect of feeding selectivity on the transfer of methylmercury (MeHg) through the food chain. Total Hg concentrations in Chlorella sp., Nitzschia closterium and Isochrysis galbana exposed to 1 μg L−1 MeHg for three days were 27.91, 32.74 and 40.03 μg g−1 respectively and were significantly different (p < 0.05) between species. Moina mongolica and Artemia sp. primarily selected Chlorella sp. as the sole diet, though the Artemia sp. partly grazed on I. galbana as well. Harpacticus uniremis, however, preferred to graze N. closterium and I. galbana and avoided Chlorella sp. The varying concentration of Hg in the microalgae species as well as the selectivity of zooplankton to the algal diet resulted in varying Hg accumulation in three zooplankton species (M. mongolica < Artemia sp. < H. uniremis with total Hg concentrations of 0.14, 0.66 and 0.82 μg g−1, respectively). Scophthalmus maximus and Paralichthys olivaceus mainly preyed on H. uniremis and partly on M. mongolica, while Fugu rubripes primarily preyed on M. mongolica and secondarily on Artemia sp. Thus, similar reasoning as above could explain the significant difference in Hg accumulation in the fish (S. maximus > P. olivaceus > F. rubripes with total Hg concentrations of 0.0042, 0.0031 and 0.0020 μg g−1, respectively). These investigations suggested feeding selectivity plays a key role in the transfer of MeHg along marine food chains. 相似文献
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Samples of the polychaete Chaetopterus variopedatus, worm tubes, commensal crab Polyonyx gibbesi and sediments were collected in eight sites in Todos os Santos Bay, Brazil, in order to evaluate the potential use of the polychaetes and crabs as biomonitors and to assess the relationships and accumulation of trace and major elements in different benthic compartments. Trace and major elements were determined by ICP OES. Organic carbon, total nitrogen and sulfur were determined by CNS elemental analyser. Tubes, crabs and polychaetes were important in the retention of trace and major elements. Metals that presented the highest accumulation in polychaetes (i.e. Mg > Al > Fe > Zn > Mn > Co > Cu > Ba > Cr) where the same for crabs (i.e. Mg > Al > Fe > Mn > Co > Zn > Cu > Ba > Cr). High concentrations of Al, Ba, Cr, Mn and Fe, from terrigenous sources, were observed in tubes, which presented accumulation factors up to 81.5 for Mn. Sedentary polychaetes are seen as good biomonitor alternatives for metal contamination studies, because they are one of the most abundant taxon in the benthic system, live in direct contact with sediments, are present in broad distributions and can also handle relatively high concentrations of metals ensuring chronic exposition. The possibility to work with not only the polychaete but also its tube offers advantages compared to bivalves that generally do not accumulate certain metals in very high levels. 相似文献
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1 INTRODUCTION While wastewater discharge regulations have significantly reduced water column pollution, historical and accidental releases of organic pollutants and heavy metals continue to pose an ecological threat as these contaminants have become 搃n-place?sediment pollutants. It had been previously assumed that natural attenuation processes, such as burial or biodegradation, would decrease the contamination levels in surface sediments and, thus, diminish the environmental impact of t… 相似文献
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Following the oil spill from the Russian tanker Nakhodka in 1997 in the Sea of Japan, polycyclic aromatic hydrocarbons (PAH) were monitored for three years in some molluscs from the Mikuni-cho shore in Japan. Total PAH concentrations in marine organisms except for spiny top shell, ranged from 5.3 to 32.7 ng/g wet weight, but no trends were evident. Total PAH concentration in spiny top shell (Turbo cornutus) was 44 ng/g w.w. in the first month after the oil spill. However, it rapidly decreased to less than 5.4 ng/g w.w. from the second month. Spiny top shell, which was exposed to dietary Nakhodka heavy fuel oil, concentrated benzo(a)pyrene to 17.1 ng/g w.w. after two weeks of exposure and then rapidly eliminated it during an elimination phase. These results suggest that spiny top shell accumulates PAHs because of their low ability to metabolize PAH, but it can excrete parent PAHs rapidly when removed from the source of contamination. Thus it is suitable as an indicator organism in monitoring oil contamination. It can also be inferred from these field and laboratory investigations that, in three years, organisms from the Mikuni-cho shore seem to have adequately recovered from the Nakhodka oil spill contamination. 相似文献
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Douglas H. Adams 《Marine pollution bulletin》2010,60(1):148-151
Wahoo, Acanthocybium solandri, are predatory oceanic fish that occur and are harvested in all tropical and subtropical oceans. Total mercury concentrations analyzed in dorsal muscle tissue of 208 wahoo from offshore waters of the southeastern United States and the Bahamas ranged from 0.021 to 3.4 mg/kg (wet weight), with a mean of 0.50 mg/kg (± 0.595 SD). Analyses indicated significant positive linear relationships between mercury and length, as well as, age of wahoo. The piscivorous nature, generally high trophic position, fast growth rate, and associated high metabolism of wahoo within tropical offshore pelagic environments may lead to comparatively higher concentrations of mercury over relatively short time periods. Mercury in wahoo, a highly mobile species consisting of one world-wide population, is regionally influenced by large-scale spatial differences in available mercury in selected prey fish species - many of which have been found to contain relatively high concentrations of mercury. 相似文献
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This study was undertaken to determine the cadmium removal efficiency of Lemna minor when it was used for treatment of wastewater having different characteristics, i. e., pH, temperature and cadmium concentration. Plants were cultivated in different pH solutions (4.5–8.0) and temperatures (15–35°C) in the presence of cadmium (0.1–10.0 mg/L) for 168 h. The amount of biomass obtained in the study period, the concentrations of cadmium in the tissues and in the media and net uptake of cadmium by Lemna have been determined for each condition. The percentages of cadmium uptake (PMU) and bioconcentration factors (BCF) were also calculated. The highest accumulation was obtained for the highest cadmium concentration of 10.0 mg Cd/L as 11.668 mg Cd/g at pH 6.0, and as 38.650 mg Cd/g at 35°C and pH 5.0. The cadmium accumulation gradually increased with initial concentration of the medium, but the opposite trend was observed for the PMU. However, the maximum PMU was obtained as 52.2% in the solution with the lowest concentration of 0.1 mg Cd/L. A mathematical model was used to describe the cadmium uptake and the equation obtained was seen to fit the experimental data very well. 相似文献
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《Marine pollution bulletin》2014,78(1-2):51-55
Strategies to control invasive lionfish in the western Atlantic and Caribbean are likely to include harvest and consumption. Until this report, total mercury concentrations had been documented only for lionfish from Jamaica, and changes in concentrations with increasing fish size had not been evaluated. In the Florida Keys, total mercury concentrations in dorsal muscle tissue from 107 lionfish ranged from 0.03 to 0.48 ppm, with all concentrations being less than the regulatory threshold for limited consumption. Mercury concentrations did not vary consistently with standard lengths or wet weights of lionfish. In 2010, lionfish from the upper Keys had mean concentrations that were 0.03–0.04 ppm higher than lionfish from the middle Keys, but mean concentrations did not differ consistently among years and locations. Overall, total mercury concentrations in lionfish were lower than those in several predatory fishes that support commercial and recreational fisheries in Florida. 相似文献