鄱阳湖河湖交错区软体动物重金属富集与迁移特征分析

河湖交错区是鄱阳湖流域重金属污染物进入湖泊的主要通道,也是重金属富集的场所.本文通过在鄱阳湖河湖交错区采集软体动物样品,分析样品的肌肉和内脏中铁（Fe）、锰（Mn）、铜（Cu）、锌（Zn）、铬（Cr）、镍（Ni）、砷（As）、镉（Cd）、铅（Pb）和锑（Sb）的含量,利用生物-沉积物累积因子和碳氮稳定同位素对鄱阳湖软体动物重金属的富集特征及营养结构和食源关系进行研究,并利用综合目标危险系数进行健康风险评估.结果表明：①鄱阳湖软体动物重金属含量存在显著的种间和组织间的差异,且受体长体重的稀释作用,与所在栖息地的关系不大,但与区域背景环境存在明显的对应关系,均低于水产限量标准值.软体动物对重金属Cu、Zn和Cd具有明显的富集能力,蚌（圆顶珠蚌、三角帆蚌、背瘤丽蚌和褶纹冠蚌）易从环境中富集更多的Mn和Cd,而螺（铜锈环棱螺和大沼螺）则易富集Cu和Zn;②软体动物δ¹³C值为-29.84‰~-21.13‰,δ¹⁵N值为4.09‰~11.51‰,螺和蚌存在明显不同的食物来源.软体动物中的重金属并不随δ¹⁵N值的变化表现出显著的改变,但与δ¹³C值存在显著的线性关系;其中Cu和Zn与δ¹³C值表现为显著的正相关关系,而Mn、Cr、As、Cd、Pb和Sb表现为显著的负相关关系;③健康风险评估结果表明,不论是成人还是儿童,综合目标危险系数（TTHQ） 均大于1,表明鄱阳湖河湖交错区软体动物重金属的富集会对人群食用产生较为显著的健康风险,其中Mn和As是主要的贡献者,且食用蚌的风险略高于螺.研究结果可为鄱阳湖水生态安全、水生生物多样性保护及食品安全评估提供科学依据和理论支撑.     

Molecular biomarkers of energy metabolism in mussels under anthropogenic pollution of Peter the Great Bay, the Sea of Japan

The functional state of the indicator species, the Gray mussel Crenomytilus grayanus (Bivalvia), has been analyzed in five areas of Peter the Great Bay exposed to anthropogenic pollution. The following indices of the state of mussels have been used: molecular biomarkers of energy metabolism—Na⁺,K⁺-ATPase, Mg²⁺-ATPase, and total ATPase activity—as well as the level of lipid peroxidation (LPO) and glutathione concentration in the hepatopancreas, gills, and gonads of mussels. The activity of ATPases, LPO level, and glutathione concentration significantly change in mussels from polluted areas relative to those in mussels from a conventionally unpolluted area (a bay in the Far Eastern State Marine Reserve). The molecular biomarkers used in the study provide reliable information on animal metabolism in impact areas. With consideration of the data obtained, it is concluded that the state of mussels in polluted areas is impaired.     

Assessment of Genotoxicity of Lignin Substances as Risk Factors for Aquatic Ecosystems

The genotoxicity of lignin substances (LSs) isolated from biologically purified wastewaters of the pulp and paper industry was studied in experiments on Baikal endemic mollusks and corn. Both toxicity and mutagenic activity of LSs were revealed, with their levels depending on the physicochemical characteristics of LSs, the test organism, and experimental conditions. These results provide evidence that LSs discharged into water bodies create a genetic hazard to their ecosystems.     

Bivalve mollusks in metal pollution studies: From bioaccumulation to biomonitoring

Contemporary environmental challenges have emphasized the need to critically assess the use of bivalve mollusks in chemical monitoring (identification and quantification of pollutants) and biomonitoring (estimation of environmental quality). Many authors, however, have considered these approaches within a single context, i.e., as a means of chemical (e.g. metal) monitoring. Bivalves are able to accumulate substantial amounts of metals from ambient water, but evidence for the drastic effects of accumulated metals (e.g. as a TBT-induced shell deformation and imposex) on the health of bivalves has not been documented. Metal bioaccumulation is a key tool in biomonitoring; bioavailability, bioaccumulation, and toxicity of various metals in relation to bivalves are described in some detail including the development of biodynamic metal bioaccumulation model. Measuring metal in the whole-body or the tissue of bivalves themselves does not accurately represent true contamination levels in the environment; these data are critical for our understanding of contaminant trends at sampling sites. Only rarely has metal bioaccumulation been considered in combination with data on metal concentrations in parts of the ecosystem, observation of biomarkers and environmental parameters. Sclerochemistry is in its infancy and cannot be reliably used to provide insights into the pollution history recorded in shells. Alteration processes and mineral crystallization on the inner shell surface are presented here as a perspective tool for environmental studies.     

湛江硇洲岛海域19种贝类食用部位的重金属含量及评价

测定了湛江硇洲岛海域产的17种腹足类足部肌肉和2种双壳类软体部的Cr、Cu、Zn、Ni、As、Cd、Pd和Hg等8种重金属质量分数。通过对比金属污染指数,发现桶形芋螺Conus betulinus、粗糙滨螺Littorinopsis scabra、鳞片扭蚶Trisidos kiyonoi、可变荔枝螺Thais mutabilis和小结节滨螺Nodilittorina exigua受到的污染较严重;以单因子污染指数为标准,无Cu、Zn和Ni污染,Pd和Hg仅少数种轻微污染,Cr污染较严重,Cd和As污染非常严重;以重金属绝对质量分数来衡量,含As、Cr和Cd最高的贝分别是黑凹螺Chlorostoma nigerrina、粒花冠小月螺Lunella corontat和习见赤蛙螺Bursa rana。     

深圳蛇口港及深圳湾潮间带动物的有机锡污染

以异辛烷为萃取剂、四乙基硼化钠为衍生剂对样品进行同步化液-液萃取衍生反应,采用气象色谱-火焰光度检测法,研究了深圳蛇口港及深圳湾海域潮间带动物的有机锡污染状况。结果显示,所有站位采集的双壳类体内普遍检测出三苯基锡、三丁基锡及其降解产物二丁基锡,含量分别为127.1～349.1、6.3～380.8及2.7～99.9ng/g(湿重)。采自赤湾和东角头的渔舟蜒螺体内存在较高含量的三苯基锡567.3～651.6ng/g(湿重)。所有软体动物均未检测出单丁基锡。采自红树林的纹藤壶含127.1ng/g(湿重)的三苯基锡,但未检测出丁基锡。文章结果与国内外已有的相关数据比较表明,蛇口港潮间带动物已经受到较严重的有基锡污染,深圳湾的海洋生物也受到一定程度的污染。深圳湾红树林国家自然保护区对于生物多样性的维持及侯鸟的保护都极其重要,该海区的有机锡污染问题需要引起高度重视。     

Chemical extractions and predicted free ion activities fail to estimate metal transfer from soil to field land snails

This study investigates the relevance of several soil chemical extractions (calcium chloride, acetic acid, citric acid and a four-step sequential procedure) and predicted free metal ion activities in the soil solution to characterise the transfer of trace metals (Cd, Pb, and Zn) from soil to snail soft tissues over a large smelter-impacted area (Metaleurop Nord, Nord-Pas-de-Calais, France). The study was first performed on six snail species together and then specifically on Cepaea sp. and Oxychilus draparnaudi. When the six species were considered together, the accumulation of metals depended mostly on the species. When significant, total or extractable metal concentrations, or the predicted free ion activities, accounted for less than 7% of the variation of the metal concentrations in the snail tissues. Species-specific analyses showed that extractable concentrations explained approximately 25% of the variation of the metal concentrations in O. draparnaudi, and up to 8% in Cepaea snails. When using total soil concentrations and soil properties as explanatory variables, the models were generally slightly better, explaining up to 42% of the variance. The soil extraction procedures and predicted free ion activities used in this study did not accurately estimate the metal transfer from soil to snails and could not be used in risk assessment.     

Heavy metal accumulation by freshwater hydrobionts in a mining area in the south of the Russian Far East

The contents of heavy metals (HMs) were studied in freshwater hydrobionts from the south of the Russian Far East, including the area of wastewater discharge from a lead smelter (the village of Rudnaya Pristan, Primorye). The results showed that most invertebrates disappeared from the ecosystem as the toxicity of the aquatic environment increased. Mollusks of the genus Lymnaea proved to be most tolerant of HM pollution. As the contents of Pb, Mn, Cd, and Zn in bottom sediments increased, the amounts of these metals in mollusk bodies increased as well but to a much lesser extent, with the intensity of HM accumulation decreasing at their higher concentrations in the environment. The range of HM concentrations accumulated in the bodies of limneids noticeably broadened with an increase in technogenic impact. This is evidence for differences in the efficiency of mechanisms regulating the contents of trace elements in individuals of the same species under conditions of extreme pollution.     

Genesis of epizootics involving introduced species of helminths,mammals, and mollusks

The functioning of two foci of helminth diseases caused by trematodes Apophallus muehlingi and Rossicotrema donicum has been studied in the Volga Delta. The origin of these foci is related to the expansion of species ranges of Lithoglyphus snails, intermediate hosts of trematodes. Introduced mammal species, the raccoon dog Nyctereutes procyonoides and American mink Mustela vision, are involved in the circulation of the invasion.     

Use of Stable Nitrogen Isotopes and Permeable Membrane Devices to Study what Factors Influence Freshwater Mollusk Survival in the Conasauaga River

Recent biological inventory data shows severe declines in freshwater mussel abundance and biodiversity in the Conasauga River Basin in Northwest Georgia, USA. Based on assessments of habitat conditions, mussel populations should be sustainable. We conducted a study of sediment and water quality to evaluate the impact of anthropogenic contamination on mussel populations. Permeable membrane devices (PMD), polar organic chemical integrative samplers (POCIS™), conventional water and sediment quality analyses, and stable nitrogen isotope ratio analyses (δ¹⁵N) of snails and sediments were used to assess sediment and water quality at target sites throughout the basin. Ambient concentrations of organic contaminants in water were well below any aquatic life criteria; concentrations of some nutrients were detected above aquatic life criteria levels. Most mussel species in the river are endangered or threatened; therefore, snails were collected for δ¹⁵N analyses. Mean δ¹⁵N values for snails collected at forested upper watershed sites (national forest areas) were significantly lower than δ¹⁵N values from snails in agricultural areas. δ¹⁵N values for raw cow manure and manure-treated soil were similar to δ¹⁵N values for snails collected in agricultural areas. Dissolved nitrate from water samples had elevated δ¹⁵N values similar to the upper range of δ¹⁵N values for snails in agricultural areas. Data, particularly stable nitrogen isotope data, indicates that a land use change from national forest land to agriculture alters nitrogen sources to the basin and snails. Implications of nutrient release on freshwater molluscan reproduction, growth, and survival are discussed.