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191.
太湖梅梁湾沉积物中多环芳烃的生态和健康风险   总被引:12,自引:4,他引:8  
持久性有机物引起的水质安全性问题日益受到广泛的关注.利用生态和健康风险评价的原理和方法,对太湖梅梁湾水源地沉积物中的多环芳烃可能导致的负面效应进行了分析.首先采用商值法筛选出该地区沉积物中具有潜在风险的多环芳烃,再进一步用建立在暴露浓度分布和物种敏感度分布上的概率法定量表征风险.结果表明,太湖梅梁湾水源地沉积物的多环芳烃中,菲、荧蒽、芘、苯并[a]蒽、屈、苯并[a]芘、二苯并[a,h]蒽7种具有潜在风险;在保护95%的物种水平下,菲的风险最小,而荧蒽和芘风险较高,达20%.健康风险分析表明,美国EPA提出的7种具有遗传毒性的多环芳烃其致癌风险在梅梁湾沉积物中均在10-5水平以下.  相似文献   
192.
This study was undertaken to determine the importance of riparian buffers to stream ecology in agricultural areas. The original Maryland Biological Stream Survey (MBSS) data set was partitioned to represent agricultural sites in Maryland's Coastal Plain and Piedmont regions. ANOVA, multiple linear regression (MLR), and CART regression tree models were developed using riparian and site catchment landscape characteristics. MBSS data were both stratified by physiographic region and analyzed as a combined data set. All models indicated that land management at the site was not the controlling factor for fish IBIs (FIBI) at that site and, hence, using FIBI to evaluate site-scale factors would not be a prudent procedure. Measures of instream habitat and location in the stream network were the dominant explanatory factors for FIBI models. Both CART and MLR models indicated that forest buffers were influential on benthic IBIs (BIBI). Explanatory variables reflected instream conditions, adjacent landscape influence, and chemistry in the Coastal Plains sites, all of which are relatively site specific. However, for Piedmont sites, hydrologic factors were important, in addition to adjacent landscape influence, and chemistry. Both Coastal Plain and Piedmont CART models identified several hydrologic factors, emphasizing the dominant control of hydrology on the physical habitat index (PHI). Riparian buffers were a secondary influence on PHI in the Coastal Plain, but not in the Piedmont. Between 40% and 70% of the variation in FIBI, BIBI, and PHI was explained by the “easily obtainable” variables available from the MBSS data set. While these are empirical results specific to Maryland, the general findings are of use to other locations where the establishment of forest buffers is considered as an aquatic ecosystem restoration measure.  相似文献   
193.
A multivariate approach was used to test the value of intertidal communities as a bioindicator of environmental conditions at Algeciras Bay, southern Spain. The study area is located in the Strait of Gibraltar and it is subjected to a variety of anthropic impacts. Eight localities (5 inside and 3 outside the bay) were selected, and four transects were undertaken in each locality to characterise the fauna and flora. The spatial distribution of the intertidal species reflected the physico-chemical conditions of Algeciras Bay. The stations located outside the bay, characterised by high hydrodynamism and dissolved oxygen and low sedimentation and turbidity, had a higher diversity and species richness than the inner stations. According to the BIO-ENV procedure and CCA, water turbidity was the factor which best correlated with the intertidal assemblages. SIMPER showed that the molluscs Chtamalus stellatus, Mytilus cf edulis, Littorina neritoides and Balanus perforatus, and the algae Gelidium pusillum, Corallina elongata, Asparagopsis armata, Colpomenia sinuosa and Fucus spiralis were the species that most contributed to the dissimilarity between internal and external sites. The present study, based on the spatial distribution of intertidal taxa, yielded similar results to those previously obtained in the area with costly physico-chemical analysis based on complex matrices of subtidal epifaunal communities. Consequently, the intertidal sampling method proposed in this study is presented here as a quick, effective alternative strategy, and can be useful in environmental monitoring programs, since these communities are easily accessible and amenable to sample, and the sessile nature of the majority of the species makes future, long-term monitoring relatively simple.  相似文献   
194.
地理信息系统支持下的区域环境质量现状评价   总被引:4,自引:0,他引:4  
针对我国区域环境现状评价工作中的实际问题,在地理信息系统PURSIS的支持下,作者设计了一种离散点插值或趋势面拟合扩展的方法,将以往侧重于监测点逐点评价扩展为在整个空间区域上进行评价,即通过扩展模型获得评价因于浓度空间分布图,在此基础上进行环境因子单项或综合评价。在福建湄洲湾环境质量现状评价中,用这种方法,可以统计出污染物的超标面积及分布区域,并进行年际比较,取得了更为科学、实用的评价结果。  相似文献   
195.
以台州(乐清湾)为例,研究了乐清湾海域生物体内多氯联苯(PCBs)的分布,其中以鱼、贝类和虾为主要实验对象,分析了多氯联苯的来源、浓度及各种影响因素。结果表明,鱼肉中∑PCBs 的残留含量为8.61~23.06ng/g,贝类中∑PCBs 的残留含量为11.77~38.04ng/g,对虾中∑PCBs的残留含量为0.38~11.19ng/g。近海生物体内多氯联苯的来源与当地工业排污、航运、PCBs废旧设施非法处置或封存不当等一系列因素有关。  相似文献   
196.
确定自然海岸特征是海岸修复中的重要内容,但是在开发后弃管的无居民海岛却面临缺少历史资料参考的困难。在大连普兰店湾中部前大连岛的研究证明,依据历史影像和现存海岸地质地貌情况可以分析确定原自然海岸位置及性质。1972年KH 卫星影像表明当时的前大连岛仍然保持自然海岸形态,海岸位置在2020年海岸后 方的岛屿陆域内部。结合2020年海岸地质考察结果可以进一步确定1972年的前大连岛东部、西部分布海蚀崖形式的基岩海岸,南部、北部则分布砾石质海岸。1972—2020年,前大连岛自然海岸全部变化为人工海岸,海岸长度也从约2.38 km 增加至约3.12 km。  相似文献   
197.
Evans et al. (Journal of Agricultural and Environmental Ethics, 2008) have attempted to enmesh me in their dispute with the Florida Bureau of Invasive Plant Management about a specific system, Kings Bay/Crystal River. In so doing, they repeatedly mischaracterize my positions in order to depict, incorrectly, invasion biology as monolithic and me as a representative of one extreme of a false dichotomy about management of introduced species. In addition, they introduce an issue irrelevant in this case (extinctions) and cite incorrect data. Proposing to manage people, manatees, introduced plants, and cyanobacteria in Kings Bay by participative adaptive management, they ignore the fact that living organisms can both disperse autonomously and hitchhike. Finally, they present few details on any aspect of their management proposal and do not address the myriad problems that have beset previous attempts at scientific adaptive management, especially at large scales. Until such a management approach is fleshed out and implemented, it is impossible to assess its validity for Kings Bay, and it is very premature to suggest it as a general model for dealing with invasive species disputes.  相似文献   
198.
Our recent paper advocating adaptive management of invasive nonnative species (INS) in Kings Bay, Florida received detailed responses from both Daniel Simberloff, a prominent invasion biologist, and Mark Sagoff, a prominent critic of invasion biology. Simberloff offers several significant lines of criticism that compel detailed rebuttals, and, as such, most of this reply is dedicated to this purpose. Ultimately, we find it quite significant that Simberloff, despite his other stated objections to our paper, apparently agrees with our argument that proposals for alternative management of established INS (i.e., alternatives to minimization/eradication) should not be rejected on an a␣priori basis. We argue that more specific development and application of adaptive approaches toward INS management, whether in Kings Bay or other appropriate case studies, would be facilitated if ecosystem managers and invasion biologists follow Simberloff’s lead on this key point. While Sagoff largely shares (and, indeed, served as a primary source for developing) our general arguments that challenge common moral and scientific assumptions associated with invasion biology, he does question our suggestion that participatory adaptive management provides an appropriate framework for approaching environmental problems in which science and politics are inherently entangled. We attempt to answer this criticism through a brief sketch of what participatory adaptive management might look like for Kings Bay and how such an approach would differ from past management approaches.  相似文献   
199.
Concentrations of total aromatic hydrocarbons and extractable organic matter in the water column and sediment were determined in samples collected in the course of the last 20 years from the Salina Cruz Harbor, México, to assess the degree of organic contamination. In sediments, organic compounds accumulate in shallow areas mostly associated with extractable organic matter and fine fractions. Calculated geocumulation index and enrichment factors suggest that contamination could be derived from anthropogenic activities attributed to harbor and ship scrapping activities, as well as transboundary source. Concentration of total aromatic hydrocarbons (as chrysene equivalents) ranged from 0.01 to 534 μg l−1 in water, and from 0.10 to 2,160 μg g−1 in sediments. Total aromatic concentration of 5 μg g−1 is proposed as background concentration.  相似文献   
200.
为了探究浮游细菌和蓝藻暴发之间的关系,利用实时荧光定量PCR和高通量测序技术,对夏季蓝藻暴发期间太湖竺山湾表层水和底泥中浮游细菌群落结构和多样性进行研究。结果表明,从门水平来看,水样和底泥中平均相对丰度最高的为变形菌门,放线菌门次之,此外蓝藻门也有一定的比例,可为水华暴发提供预警指示;从属水平来看,水样中的优势细菌主要为GpXI和GpIIa,底泥中为Gp6和GpIIa。  相似文献   
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