PCB Levels and Trends Within the Detroit River-Western Lake Erie Basin: A Historical Perspective of Ecosystem Monitoring

An international workshop held in the spring of 2002 convened a group of technical experts to address monitoring, modeling, and management of PCBs within the Detroit River-Western Lake Erie basin. Participants shared and discussed a diverse set of research data bases pertaining to PCB levels within the region, discussed observed changes within different components of the local ecosystem, and identified several primary issues impacting future PCB management strategies. Results presented at the workshop indicate dramatic reductions in PCB contamination levels have been observed in much of study area between the late 1970s and mid-1990s. Estimates of loadings attributable to water and atmospheric sources have generally declined, as have PCB concentrations in herring gull eggs, smelt and walleye. Nevertheless, additional improvements have not been observed during recent years and elevated contamination levels remain a concern within local hot spots, particularly in the lower Detroit River and Trenton Channel. A primary recommendation broadly supported by workshop participants is the need to maintain, support, and coordinate a comprehensive ecosystem monitoring program for the Detroit River-Western Lake Erie basin, one that incorporates both near-field and far-field monitoring elements. Such a program is crucial to provide necessary data in support of understanding ecosystem trends, calculating annual mass loadings to the system, assessing impacts of remediation actions, developing improved modeling frameworks, and formulating cost-effective management strategies for the future.     

Temporal and Spatial Trends in Chlorinated Hydrocarbon Concentrations of Mink in Canadian Lakes Erie and St. Clair

Mink (Mustela vison) carcasses were collected from local commercial trappers from fall 1998 to spring 2003 from tributaries and marshes within 4.8km from the shores of Lakes Erie and St. Clair, including the Wheatley Harbour and St. Clair River Areas of Concern (AOCs), as well as from inland sites (8 to 40km from shore). Liver concentrations, on a lipid weight basis, of chlorinated hydrocarbons were measured and compared among sites and to tissue concentrations of mink from two previous collections from similar sites over the past 25 years. Mink from the western Lake Erie sites, which included the Wheatley Harbour AOC, had significantly higher concentrations of sum PCBs and PCB Aroclors than those from the St. Clair corridor or inland sites, with concentrations from the rest of Lake Erie being intermediate. Dieldrin concentrations were also significantly higher in western Lake Erie than many other sites, and those of oxychlordane and mirex also tended to be higher (0.05 < p < 0.1). There were no differences in contaminant concentrations between the St. Clair River AOC and the downstream non-AOC Lake St. Clair site, with the exception of slightly higher levels of octachlorostyrene (OCS). Concentrations of PCBs and other chlorinated hydrocarbons in mink showed a general decrease over the past two decades. In contrast, PCBs and some organochlorine pesticides tended to increase, significantly so with oxychlordane, in western Lake Erie mink over the same time period. DDE declined at all sites. Currently, mink liver PCB concentrations are within the range associated with reproductive impairment, as determined from captive mink studies, in 11.7% of all animals collected from the Lakes Erie and St. Clair basin overall, but in almost 40% of individuals from western Lake Erie.     

Application of a Sediment Quality Index to the Lower Laurentian Great Lakes

A sediment quality index (SQI) was developed using an equation incorporating three elements; scope--the % of variables that did not meet guidelines; area frequency--the % of failed tests divided by the total number of tests in a group of sites; and amplitude - the magnitude by which failed variables exceeded guidelines. The SQI calculation produces a numerical score with a maximum value of 100 representing the highest sediment quality. A modified SQI was also developed using only the scope and amplitude elements, which computed a score per site with no grouping. The SQI was applied to assessment of sediment quality in Lakes Erie and Ontario using Canadian Federal and Ontario Provincial guidelines for 34 compounds, Spatial trends in sediment quality in both lakes reflected overall trends for most individual contaminant classes, including mercury and polychlorinated biphenyls. In Lake Erie, there was a trend toward lower SQI values from the eastern basin to the western basin, and from the northern area to the southern area of the central basin. Sediment quality in the eastern basin and the northern area of the central basin was classified as excellent (>95); sediments in other areas of Lake Erie ranged from fair to good. In Lake Ontario, the poorest sediment quality was associated with the three major depositional basins; sediment quality among the three basins was quite consistent. The SQI values based on all three elements (scope, frequency and amplitude) for the Niagara basin. Mississauga Basin and Rochester Basin were 67 (fair), 65 (fair) and 70 (fair), respectively. Comparison of SQI values for all lower lake basins showed generally poorer sediment quality in Lake Ontario, compared to Lake Erie.     

Metals Associated with Suspended Sediments in Lakes Erie and Ontario, 2000–2002

Sediment traps were deployed in the three major basins of Lake Erie, and the central (Mississauga) basin of Lake Ontario, and refurbished seasonally over the period 2000–2002. In Lake Ontario, sediment down-flux rates and corresponding contaminant down-flux rates were highest in winter during periods of unstratified thermal conditions, and generally increased with depth due to the influence of resuspended bottom sediments during all sampling periods. Lake Ontario suspended sediments exhibited the highest concentrations of metals; concentrations of mercury and lead frequently exceeded guideline values for bottom sediments. Contaminant levels in Lake Ontario suspended sediments were similar to concentrations in bottom sediments in the same area. There was a spatial trend toward higher suspended sediment metals concentrations from the eastern basin to the western basin of Lake Erie, which is similar to the trend in bottom sediment contamination. In the eastern basin of Lake Erie, which is the deepest area of the lake, there was no trend in down-flux rate with depth in 2001; however, down-flux rates increased with depth in 2002. Suspended sediments in the western basin of Lake Erie were determined to be largely resuspended bottom sediments; all western basin samples collected in the study exceeded the guideline value for mercury (0.486 μg/g).     

Assessment of water quality of Rawal Lake by long-time monitoring

Water quality of rivers, natural lakes, and reservoirs in developing countries is being degraded because of the contaminated inflows. There is a serious need for appropriate water quality monitoring for future planning and management of clean water resources. Quality of water in Rawal Lake Pakistan has been investigated in this paper. Flows from the upstream of Rawal Lake and its surrounding villages are highly polluted. Lake water quality parameters like pH, turbidity, alkalinity, calcium, nitrite, sulfate, biological oxygen dissolved, dissolved oxygen, chloride, total dissolved solids (TDS), and coliforms were investigated. Samples of water from different locations of Korang River were collected and tested. Most of the data was collected by field sampling and field visits. However, long-term information was taken from different departments. Statistical parameters (standard deviation, maximum, minimum, mean, mode, kurtosis, skew, and Euclidean distance) of variables were determined. A distinct parameter based on the difference of the maximum value the variable and maximum allowable value of that variable defined by World Health Organization was used for analysis. Grouping and clustering of elements was made on the basis of this parameter. Trend of increasing or decreasing of values of variables over a long time was also taken into account for grouping the variables. It was concluded that the concentration of seven contaminants was higher as compared to the permissible limits under environmental standards. These variables need immediate attention. The environmentally bad conditions of Rawal Lake can only be rectified by appropriate lake environmental supervision, watershed management, and implementation of environmental legislation.     

Lake Ontario sediments in monitoring pollution

An investigation was carried out to select locations for long-term monitoring of inputs of contaminants into Lake Ontario using fine-grained bottom sediments as an historical record of pollution. The sediment sampling program was designed to determine sediment heterogeneity in the western, central and eastern depositional basins of the lake. Surficial sediments and sediment cores were collected in each basin to obtain information on horizontal distribution and concentration profiles of major and trace elements in the sediments (Si, Al, Ca, Mg, Fe, Na, K, Ti, Mn, P, As, Co, Cu, Cr, Ni, Pb and Zn). The results of the investigation indicated that fine-grained sediments in three Lake Ontario depositional basins are homogeneous to a high degree, and that only a few sediment cores need to be collected within each basin for the long-term monitoring of inputs of contaminants to the lake.     

1987—2016年太湖总氮浓度变化趋势分析

基于可获取的太湖国控监测点位总氮监测数据，分析了1987—2016年太湖总氮浓度变化趋势。结果表明，近30年来，太湖湖体总氮浓度年均值在1.74~3.88 mg/L之间，总体呈先上升、后下降的波动变化趋势，1996年浓度达历史峰值；其变化具体可分为上升期、波动期、下降期三个阶段，约以10年为一个阶段。分湖区分析，西部湖区、北部湖区2000—2016年总氮年均浓度与全湖总氮浓度呈明显的正相关，为影响湖体总氮浓度的主要湖区。总氮多年月均值浓度变化显示，2000—2016年湖体总氮多年月均值年内呈较明显的季节变化规律，月均最大值、最小值分别出现在3月和9月。空间变化分析表明，西部湖区的宜武片区及南部湖区的湖州长兴片区为湖体总氮的两个污染扩散核心。湖体总氮主要受15条主要入湖河流汇入影响，这些河流总氮年均浓度整体高于湖体，是太湖总氮治理的重点。     

Monitoring the Elimination of Persistent Toxic Substances from the Great Lakes; Chemical and Physiological Evidence from Adult Herring Gulls

To assess progress towards virtual elimination of PCBs, DDE, dieldrin and Mirex and their associated physiological effects, we compared their concentrations in pooled livers of adult herring gulls (Larus argentatus) repeatedly sampled at 8 Great Lakes colonies and a reference colony on the Atlantic coast between 1974 and 1993. We measured the relative thyroid mass and concentrations of highly carboxylated porphyrins and retinyl palmitate in the liver of each individual. PCBs, dieldrin and mirex declined in 7 of 8 colonies while DDE decreased in six. The greatest decreases occurred pre-1985. PCBs and DDE did not decrease in gulls from Middle Island in western L. Erie. Middle Island and Saginaw Bay had the highest concentrations of PCBs of 11 Great Lakes colonies in the 1990s. Thyroids of gulls from Great Lakes colonies were slightly enlarged but the degree of enlargement has decreased over time. In 1991, gulls from Great Lakes colonies had slight to moderately elevated concentrations of highly carboxylated porphyrins. In the early 1990s, hepatic stores of retinyl palmitate were very seriously depleted in gulls from the Detroit River, western basin of Lake Erie, and Lake Ontario, reflecting decreased availability and altered storage. We conclude that PCBs and/or other persistent toxic substances in the food of herring gulls have not been virtually eliminated.     

牛栏江流域水污染时空分布与防治对策措施研究

根据昆明市环境监测中心2004～2008年连续5年对昆明辖区牛栏江流域河道及库区水质监测的结果,对牛栏江-滇池补水工程昆明辖区流域的水环境质量现状进行了分析研究,探讨了该流域段水污染的时空分布,就此提出水污染防治对策措施建议.     

滴水湖水质现状及保护初探

滴水湖的水源大治河水质较差,总体为V类。滴水湖生态系统脆弱,水体已呈富营养化,2006年—2008年连续3年的湖水年平均富营养化指数(TLI)均超过了70,透明度呈逐年下降趋势,氮、磷是滴水湖污染最重要的因素。据此,提出了"立法先行、加强监管、污染控制、生态修复、硬件保障、科技创新"的滴水湖水质保护思路。     

太浦河界标断面水质达标综合治理对策

简述了太浦河界标断面2020年水质考核目标以及区域水污染现状。指出,界标断面水质主要超标因子为DO和TP,农业面源污染、工业污染、生活污水处理相对滞后、内源污染、部分黑臭河道河段清淤不彻底是导致区域水污染的主要因素。提出,要推进农业面源污染治理,强化工业污染源治理,加强区域性污染物控制以及生活污染源整治,促进河湖生态系统恢复,加强自动监测站管理工作。     

Investigations of mercury concentrations in walleye and other fish in the Athabasca River ecosystem with increasing oil sands developments

Recent studies have reported an increasing trend of mercury concentrations in walleye (Sander vitreus) from the Athabasca River, north eastern Alberta (Canada); these studies were based on three years of comparison and attributed the mercury increase to expanding oil sands developments in the region. In order to conduct a more comprehensive analysis of mercury trends in fish, we compiled an extensive database for walleye, lake whitefish (Coregonus clupeaformis), northern pike (Esox lucius) and lake trout (Salvelinus namaycush) using all available data obtained from provincial, federal, and industry-funded monitoring and other programs. Evidence for increasing trends in mercury concentrations were examined for each species by location and year also considering fish weight and length. In the immediate oil sands area of the Athabasca River, mercury concentrations decreased (p < 0.001) in walleye and lake whitefish over 1984-2011. In western Lake Athabasca and its delta, mercury concentrations decreased (p < 0.0001) in northern pike (1981-2009) although no trend was evident for walleye (1981-2005) and lake trout (1978-2009). Mercury concentrations in lake trout from Namur Lake, a small lake west of the oil sands area, were higher in 2007 than 2000 (p < 0.0001); it is difficult to ascribe this increase to an oil sands impact because similar increases in mercury concentrations have been observed in lake trout from similar sized lakes in the Northwest Territories. While mercury emissions rates have increased with oil sands development and the landscape become more disturbed, mercury concentrations remained low in water and sediments in the Athabasca River and its tributaries and similar to concentrations observed outside the development areas and in earlier decades. Our fish database was assembled from a series of studies that differed in study purpose, design, and analytical methods. Future monitoring programs investigating mercury trends in fish should be more rigorous in their design.     

太湖水环境时空演变及污染特征分析

分析研究太湖30年来的水质演变及近年来的水文径流数据,得出了太湖中存在的主要湖流。同时结合太湖特定的地理条件及水文特点,将大太湖分成湖岸区、过渡区和湖心区,对比分析了各个湖区间水质的相互影响及变化规律,得出了太湖的主要污染特征。     

洪泽湖流域生态环境问题及治理对策

分析了洪泽湖水环境和污染源特征,针对存在的氮磷超标导致湖体富营养化、生态退化以及入境客水污染等主要环境问题,提出制订入湖河流TN标准、控制污染物排放总量、修复湖泊生态、治理客水和强化水质监控等措施,为有效地改善洪泽湖水环境质量,遏制湖泊富营养化趋势提供科学支撑。     

云龙湖水质调查与评价

对云龙湖水质进行了调查与评价.在云龙湖东湖、西湖区各设置3个采样点,监测水体中TN、TP、Imn、NH3-N、DO和SD指标;分别使用模糊识别法和湖泊综合营养指数对水体进行水质评价与富营养化评价,结果表明,云龙湖水质级别为III类,其中TN、TP超标明显,水体呈现中度富营养化;不同功能区水质差异明显,东湖区水质优于西湖...     

滇池东南岸农业和富磷区入湖河流地表径流及污染特征

应用聚类分析与因子分析方法,通过8次常规监测,对滇池东南岸10条以农业面源和受磷矿开采区影响的入湖河流的地表径流及其水质污染特征进行了分析,并探讨了其空间差异性。在南岸选取降雨过程相同的3条河流,开展暴雨径流监测,探讨污染物在降雨过程中的流失特征。结果表明,新宝象河的平均流量为2.6 m3/s,占总入湖流量的26.5%;总氮、总磷、化学需氧量、悬浮物是滇池的主要污染指标,许多河流均已严重超标。河流水质在空间上可分为3类,具有明显的空间差异性。总氮、总磷、溶解磷、硝态氮对水质污染的贡献率达到了53.636%,氮、磷含量是河流水质污染的主要贡献因子。降雨条件下化学需氧量、悬浮物浓度增长迅速,流量、悬浮物与大多数水质指标均有相关性,磷矿开采对河流水质的影响在降雨条件下更加明显,其悬浮物浓度在降雨条件下比只受农业面源影响的河流最高高出1.9倍。     

滇池流域水环境综合管理技术支撑平台构建研究

滇池流域水环境综合管理技术支撑平台以实现水环境数据信息化、支撑多元化、管理智能化为目标,集成水环境多元数据采集传输、融合共享及动态表征技术,突破高原湖泊流域多目标复杂环境综合管理决策控制技术,构建"数据中心-业务系统-信息发布"为主线的综合管理平台,其以水环境数据中心为支撑,以水环境信息系统与水环境专家决策支持系统为核心,以水环境信息发布系统为共享交换媒介,为流域管理提供监控预警、总量控制、预测预报、项目评估及应急决策等技术服务,有效支撑滇池流域水环境监控预警和综合管理。     

From lake to estuary,the tale of two waters: a study of aquatic continuum biogeochemistry

The balance of fresh and saline water is essential to estuarine ecosystem function. Along the fresh-brackish-saline water gradient within the C-43 canal/Caloosahatchee River Estuary (CRE), the quantity, timing and distribution of water, and associated water quality significantly influence ecosystem function. Long-term trends of water quality and quantity were assessed from Lake Okeechobee to the CRE between May 1978 and April 2016. Significant changes to monthly flow volumes were detected between the lake and the estuary which correspond to changes in upstream management. and climatic events. Across the 37-year period, total phosphorus (TP) flow-weighted mean (FWM) concentration significantly increased at the lake; meanwhile, total nitrogen (TN) FMW concentrations significantly declined at both the lake and estuary headwaters. Between May 1999 and April 2016, TN, TP, and total organic carbon (TOC), ortho-P, and ammonium conditions were assessed within the estuary at several monitoring locations. Generally, nutrient concentrations decreased from upstream to downstream with shifts in TN/TP from values >?20 in the freshwater portion, ~?20 in the estuarine portion, and <?20 in the marine portion indicating a spatial shift in nutrient limitations along the continuum. Aquatic productivity analysis suggests that the estuary is net heterotrophic with productivity being negatively influenced by TP, TN, and TOC likely due to a combination of effects including shading by high color dissolved organic matter. We conclude that rainfall patterns, land use, and the resulting discharges of runoff drive the ecology of the C-43/CRE aquatic continuum and associated biogeochemistry rather than water management associated with Lake Okeechobee.     

Developing an environmental water quality monitoring program for Haraz River in Northern Iran

Water quality management plans are an indispensable strategy for conservation and utilization of water resources in a sustainable manner. One common industrial use of water is aquaculture. The present study is an attempt to use statistical analyses in order to prepare an environmental water quality monitoring program for Haraz River, in Northern Iran. For this purpose, the analysis of a total number of 18 physicochemical parameters was performed at 15 stations during a 1-year sampling period. According to the results of the multivariate statistical methods, the optimal monitoring would be possible by only 3 stations and 12 parameters, including NH₃, EC, BOD, TSS, DO, PO₄, NO₃, TDS, temperature, turbidity, coliform, and discharge. In other words, newly designed network, with a total number of 36 measurements (3 stations × 12 parameters = 36 parameters), could achieve exactly the same performance as the former network, designed based on 234 measurements (13 stations × 18 parameters = 234 parameters). Based on the results of cluster, principal component, and factor analyses, the stations were divided into three groups of high pollution (HP), medium pollution (MP), and low pollution (LP). By clustering the stations, it would be possible to track the water quality of Haraz River, only by one station at each cluster, which facilitates rapid assessment of the water quality in the river basin. Emphasizing on three main axes of monitoring program, including measurement parameters, sampling frequency, and spatial pattern of sampling points, the water quality monitoring program was optimized for the river basin based on natural conditions of the study area, monitoring objectives, and required financial resources (a total annual cost of about US $2625, excluding the overhead costs).     

基于熵权的WQI法在鄱阳湖水质评价中的应用

基于2009—2018年鄱阳湖15个监测点位的水质监测数据,采用基于熵权改进的综合水质指数（WQI）法研究10年间该湖水质年际、季节演变特征及空间分布情况。结果表明：鄱阳湖WQI多年平均值为78.41,水质总体处于差等级,其中氮、磷污染较为严重;该湖水质空间分布差异较小,各湖区WQI较为接近,湖区西北部和东南部污染相对较为严重;该湖夏季水质较好,水质与降水量及湖面风浪强度紧密相关;该湖污染物主要来自入湖河流周边的工、矿、企业的废水及采砂造成的污染物释放,建议控制、治理入湖河流水质,提高鄱阳湖较重污染区水质。