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101.
双酚A(BPA)和三氯生(TCS)是两种受广泛关注的典型环境内分泌干扰物,而长江口-杭州湾是我国最主要的海产品生产海域之一,因此,长江口-杭州湾海洋生物中BPA和TCS的污染特征应引起重视。检测了长江口-杭州湾26种海洋生物体(17种鱼类、6种软体动物、3种甲壳类)肌肉组织中BPA和TCS的浓度分布特征,结果显示:所有海洋生物样品中都可检出BPA,其浓度为0.14~18 ng/g(平均5.2 ng/g);73%的海洋生物样品中含有TCS,其浓度为P<0.01);鱼类、软体动物、甲壳类中BPA和TCS的平均浓度分别为5.8、5.2、2.3 ng/g和12、15、28 ng/g;据估算,浙江普通居民通过食用海洋生物对BPA和TCS的每日摄入量均值分别为5.6 ng/kg和15 ng/kg。  相似文献   
102.
Spatial Extent of Sediment Toxicity in U.S. Estuaries and Marine Bays   总被引:1,自引:0,他引:1  
Acute, laboratory toxicity tests were performed by the National Oceanic and Atmospheric Administration (NOAA) on 1543 surficial sediment samples collected during 1991 through 1997 throughout 25 estuaries and marine bays. Selected areas were sampled along the Atlantic, Gulf of Mexico, and Pacific coasts. The toxicity of each sample was determined with 10-day amphipod survival tests performed with solid-phase (bulk) sediments. Collectively, the 1543 samples tested through 1997 represented a total area of approximately 7300 km2. Toxicity was observed with the amphipod survival tests in samples that represented approximately 6% of the combined area. Using similar tests conducted on samples collected in different, but overlapping, study areas, the U.S. Environmental Protection Agency (EPA) estimated that approximately 7% of the combined estuarine area sampled was toxic. Generally, toxicity was most severe in northeastern and southwestern estuaries and least prevalent in southeastern and northwestern areas. However, considerable portions of the Pacific coast have not been tested with the same methods. In tests of CYP1A enzyme induction (n=464), samples were toxic that represented about 5% of the combined study areas. Toxicity was much more widespread, however, when the results of two sub-lethal tests were analyzed. Significant results occurred in samples that represented approximately 25% and 39% of the study areas in tests of sea urchin fertilization (n=1309) and microbial bioluminescence (n=1215), respectively.  相似文献   
103.
Benthic algal assemblages, water chemistry, and habitat were characterized at 25 stream sites in the Willamette Basin, Oregon, during low flow in 1994. Seventy-three algal samples yielded 420 taxa — mostly diatoms, blue-green algae, and green algae. Algal assemblages from depositional samples were strongly dominated by diatoms (76% mean relative abundance), whereas erosional samples were dominated by blue-green algae (68% mean relative abundance).Canonical correspondence analysis (CCA) of semiquantitative and qualitative (presence/absence) data sets identified four environmental variables (maximum specific conductance, % open canopy, pH, and drainage area) that were significant in describing patterns of algal taxa among sites. Based on CCA, four groups of sites were identified: streams in forested basins that supported oligotrophic taxa, such as Diatoma mesodon;small streams in agricultural and urban basins that contained a variety of eutrophic and nitrogen-heterotrophic algal taxa; larger rivers draining areas of mixed land use that supported planktonic, eutrophic, and nitrogen-heterotrophic algal taxa; and streams with severely degraded or absent riparian vegetation (> 75% open canopy) that were dominated by other planktonic, eutrophic, and nitrogen-heterotrophic algal taxa. Patterns in water chemistry were consistent with the algal autecological interpretations and clearly demonstrated relationships between land use, water quality, and algal distribution patterns.  相似文献   
104.
An investigation of the impacts from elevated intertidal Pacific oyster culture in a New Zealand estuary showed enhanced sedimentation beneath culture racks compared with other sites. Seabed elevation beneath racks was generally lower than between them, suggesting that topographic patterns more likely result from a local effect of rack structures on hydrodynamic processes than from enhanced deposition. Compared with control sites, seabed sediments within the farm had a greater silt/clay and organic content, and a lower redox potential and shear strength. While a marked trend in macrofaunal species richness was not evident, species composition and dominance patterns were consistent with a disturbance gradient, with farm effects not evident 35 m from the perimeter of the racks. Of the environmental variables measured, sediment shear strength was most closely associated with the distribution and density of macrofauna, suggesting that human-induced disturbance from farming operations may have contributed to the biological patterns. To evaluate the taxonomic sufficiency needed to document impacts, aggregation to the family level based on Linnean classification was compared with an aggregation scheme based on `general groups' identifiable with limited taxonomic expertise. Compared with species-level analyses, spatial patterns of impact were equally discernible at both aggregation levels used, provided density rather than presence/absence data were used. Once baseline conditions are established and the efficacy of taxonomic aggregation demonstrated, a `general group' scheme provides an appropriate and increasingly relevant tool for routine monitoring.  相似文献   
105.
Synoptic data on concentrations of sediment-associated chemical contaminants and benthic macroinfaunal community structure were collected from 1,389 stations in estuaries along the U.S. Atlantic and Gulf of Mexico coasts as part of the nationwide Environmental Monitoring and Assessment Program (EMAP). These data were used to develop an empirical framework for evaluating risks of benthic community-level effects within different ranges of sediment contamination from mixtures of multiple chemicals present at varying concentrations. Sediment contamination was expressed as the mean ratio of individual chemical concentrations relative to corresponding sediment quality guidelines (SQGs), including Effects Range-Median (ERM) and Probable Effects Level (PEL) values. Benthic condition was assessed using diagnostic, multi-metric indices developed for each of three EMAP provinces (Virginian, Carolinian, and Louisianian). Cumulative percentages of stations with a degraded benthic community were plotted against ascending values of the mean ERM and PEL quotients. Based on the observed relationships, mean SQG quotients were divided into four ranges corresponding to either a low, moderate, high, or very high incidence of degraded benthic condition. Results showed that condition of the ambient benthic community provides a reliable and sensitive indicator for evaluating the biological significance of sediment-associated stressors. Mean SQG quotients marking the beginning of the contaminant range associated with the highest incidence of benthic impacts (73–100% of samples, depending on the province and type of SQG) were well below those linked to high risks of sediment toxicity as determined by short-term toxicity tests with single species. Measures of the ambient benthic community reflect the sensitivities of multiple species and life stages to persistent exposures under actual field conditions. Similar results were obtained with preliminary data from the west coast (Puget Sound).  相似文献   
106.
北方深水河流岸边带底栖动物采集方法比较研究   总被引:1,自引:0,他引:1  
深水河流底栖动物的采集比较复杂,采集结果与客观实际往往存在较大的差异,通过2012年-2015年对黑龙江、松花江和乌苏里江等11个断面15个点位的调查、监测,取得81组有效数据,利用统计学方法总结、研究,发现同一采样点不同方法之间的物种数、群落组成和评价结果均存在显著的差异,建议深水河流在应用底栖动物开展水生态评价时,应结合采样点的实际情况,尽量采用多种方法进行底栖动物的采集,合并统计的数据更能准确的代表采集点位的客观情况,是客观、准确评价水生态环境状况的前提.  相似文献   
107.
This study applied biomarkers and benthic indices at an area in North Evoikos Gulf, Greece, affected by metalliferous slag disposal. Biomarkers of antioxidant defense (catalase, glutathione S-transferase), and neurotoxicity (acetylcholinesterase) were measured in crabs Liocarcinus depurator. Iron (Fe), chromium (Cr), nickel (Ni), manganese (Mn), copper (Cu), and zinc (Zn) concentrations in sediments and crabs were also measured. High levels of all metals were found in sediments at the disposal area. Metal levels in the crabs were also higher in the disposal area although spatial differences were not as marked as in the sediments. Accordingly, biomarker responses of crabs in the disposal area were also noted suggesting impact on the antioxidant defense of the organisms against oxidative stress. Benthic indices showed disturbance in the disposal area. The combined approach of measuring biomarkers and contaminant levels in the crabs and sediment was complementary to the benthic indices approach providing indications of metal exposure related effects. Our results support the idea that a twofold monitoring approach of assessing both the benthic community structure shifts and the biomarkers and metal accumulation levels may integrate and capture both the structural and the toxicological effects of dumping onto the benthic communities.  相似文献   
108.
河流连续性概念(rivercontinuumconcept,RCC)将自然河流生态系统视为物理和生物的连续体,河流物理环境的梯度变化决定了生物的演变格局.为探索自然河流系统受人类干扰后大型底栖无脊椎动物的演变规律,作者于2002年5月、8月、11月对安徽省祁门县阊江河1~6级支流的大型底栖无脊椎动物进行了调查,共获7纲57科101属119种,计8813头,并详细记载了各级支流样点的栖境特点.运用“河流连续性概念”理论分析结果表明该河1~6级支流大型底栖无脊椎动物各取食功能团演变趋势符合该理论,但上游至下游的生物区系演替程度明显小于未受干扰的自然河流,1~6级支流各功能团的分布(P/%)梯度变化趋于平缓,仅捕食者数量分布与理论预测模式比较接近.各级支流相同取食功能团的优势类群各异,其种类的耐污能力随河流级别的增加总体呈上升趋势.同级支流各取食功能团的分布(P/%)比例存在季节性差异.图2表3参15  相似文献   
109.
福建东山湾养殖贝类重金属污染状况及健康风险评价   总被引:1,自引:0,他引:1  
为了解东山湾海水养殖贝类重金属污染状况及健康风险水平,2016年11月采集了华贵栉孔扇贝(Chlamys nobills)、菲律宾蛤仔(Ruditapes philippinarum)、鲍(Haliotis sp.)、巴非蛤(Paphia sp.)、牡蛎(Saccostrea sp.)和翡翠贻贝(Perna viridis)等6种常见贝类,对其污染指数、膳食暴露量和健康风险等进行评价。结果表明,东山湾贝类体内Cu、Zn、Pb、Cd、Cr、As和Hg含量(均值)分别为9.69、0.19、43.5、0.65、0.21、0.010和1.69μg·g~(-1),与第一类海洋生物质量标准限值相比,Cu、Pb、Zn、Cd、Cr和As的超标率分别为16.7%、83.3%、33.3%、33.3%、16.7%和100%;但除华贵栉孔扇贝Cd含量超标外,Pb、Cr、Hg和As含量均能满足食品中污染物限量标准要求。尽管东山湾贝类总致癌风险R_c=1.65×10~(-4),存在一定的健康风险,但5种贝类体内重金属含量略低于我国东部-南部沿海贝类的平均水平,且2010—2017年期间东山湾牡蛎体内重金属污染状况没有明显变化(养殖生物质量指数<5%),加上重金属膳食暴露风险较低,总非致癌风险R_n=0.94(<1),总体而言贝类质量状况尚可。  相似文献   
110.
论生物安全与我国生物安全的措施   总被引:3,自引:0,他引:3  
阐述了生物安全的概念;介绍了生物安全所受到的外来威胁;提出了我国生物安全的措施.  相似文献   
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