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2.
For the seven months terminating on 17 August 1980, primary sewage effluent was discharged into Newark Bay. From 22 July to 6 October 1980, we collected physical, chemical and biological data in the Newark Bay estuary from the lower Passaic River to New York Harbor. During the period of maximum discharge, the Passaic River and much of Newark Bay were anoxic or nearly so. Recovery of the Newark Bay water following sewage abatement took approximately 30 days. During most of the study period, a bloom of blue-green algae characterized the ‘Passaic River water’. This water was also characterized by chlorophyll-a values as high as 73 mg m ?3. Chlorophyll concentration almost always increased up the bay, along with decreasing salinity, increasing temperature, increasing phosphate-P and decreasing nitrate-N. The decrease in nitrate, however, was associated with an increase in ammonia-N and total N during the period of sewage discharge. 相似文献
4.
In order to evaluate the health status of fish inhabiting Port Phillip Bay, Australia, southern sand flathead (Platycephalus hassensis, N = 133) were collected at six stations throughout the Bay. Fish had a similar serum sorbitol dehydrogenase (SDH) activity level (p = 0.12), indicating that they were not experiencing hepatocellular injuries. Ethoxyresorufin-O-deethylase (EROD) activity was generally lower in the non-urbanized and non-industrialized southern part of the Bay. The highest EROD activity was observed in Hobson Bay, the closest station from Melbourne city. Naphthalene-type biliary metabolites were also highest in Hobson Bay with intermediate levels found in Corio Bay where refineries are present. An opposite trend was observed with the pyrene-type bile metabolites, the highest levels being observed in Corio Bay while intermediate levels were found in Hobson Bay. The ratio of naphthalene-type to benzo(a)pyrene (B(a)P)-type metabolites indicate that relatively to other sites sampled in Port Phillip Bay, Corio Bay is subjected to enriched petroleum hydrocarbons of pyrolytic origin. Temporal trends indicate that the availability of xenobiotics to fish remained unchanged over the 1990s. 相似文献
5.
For the first time during a significant oil spill, aircraft were used in preference to surface vessels to apply chemical dispersants, following the tragic accident to the French registered tanker in Bantry Bay, south-west Eire. In this particular case, with an ideally situated landing strip, close to the source of the spill of fresh crude oil, the response proved to be highly effective and prevented the vast majority of the oil lost after the 6th day from reaching the nearby shorelines. The ability of the pilot of the spray aircraft to rapidly locate and to select for treatment only those slicks or parts of slicks posing a significant threat also resulted in the minimum amount of dispersant being used to maximum effect. 相似文献
6.
This paper presents the results of an 11-year study into mudflat elevation changes within the intertidal zone at Stert Flats in Bridgwater Bay, Somerset. This site is located in the outer Severn Estuary/inner Bristol Channel which is a macro-hypertidal regime dominated by physical processes, characterized by strong tidal currents, high turbidity and a significant degree of exposure to wind generated waves. Two transects of stakes were installed perpendicular to the coast, extending seawards 300 m from the edge of the saltmarsh onto the mudflats, against which variations in accretion or erosion could be measured. The mudflats themselves consisted of an underlying consolidated clay of Holocene age and a surface veneer of fluid mud and/or mobile sand patches which varied both spatially and temporally. Mudflat development was recorded over both short-term (monthly/seasonal) and medium-term (inter-annual) timescales. The results display a significant degree of scatter over all timescales. Such variability in response may be expected in such a dynamic system where noise can be attributed to a combination of factors such as the mobility of surface fluid mud and sand patches and the migration of the underlying ridge–runnel drainage network. Despite this, the expected short-term variations related to neap–spring tidal conditions and seasonal influences were observed at a number of locations on the transects although these were weakly expressed. The over-riding feature of the profiles is a consistent long-term trend of erosion which appears to be masking shorter term trends within the dataset. Viewed over the 11-year period, the changes in mudflat elevation closely match the pattern of the index of the North Atlantic Oscillation (NAO) during the 1990s, suggesting a strong climatic control over mudflat development on a medium-term/decadal scale. Most profiles display a strong erosional trend during the early 1990s when the NAO index was positive. The erosional trend peaked in 1995 at a time during which the values for monthly winter mean significant wave height were notably high. Between 1996 and 2001 the profiles generally record accretion and the data display significant variability. This corresponds with a shift to a strongly negative and then weakly positive NAO index phase. The fact that such a general atmospheric factor correlates so closely with medium timescale elevation change is attributed to relative weakness of biological binding and burrowing at this site, and more-so to the overwhelming dominance of the physical regime, especially the tidal current and the wind–wave regime. Both the background erosional trend and the influence of the index of the NAO in controlling mudflat evolution have important implications relating to coastal management. These are discussed in relation to coastal defence measures, morphological response to major civil engineering projects (e.g. Severn Tidal Power Barrage) and the prospect of climate change, sea-level rise and a possible increase in strength of NAO conditions in the future. 相似文献
8.
2007年4月25日起太湖梅梁湾暴发了大规模藻类水华暴发时间比过去提前近1个月.根据中国科学院太湖湖泊生态系统国家野外科学观测研究站的监测,5月2日梅梁湾所有测点藻类叶绿素a含量全部超过40μg/L,其中三山-鼋头渚水域达179μg/L;5月27日的卫星影像图片显示,太湖北部的竺山湾和贡湖湾以及整个西部湖区均发生了大面积的蓝藻水华;随后5月28日晚,无锡贡湖湾口南泉水厂发生污水团进入水厂取水口恶化水源水质事件,给人民的日常生活带来了短暂的影响. 相似文献
9.
This paper describes measurements of suspended sediment fluxes at a total of 32 stations situated on four reference sections in the turbid estuary of Chignecto Bay, Bay of Fundy, Canada. The purpose of the study was to determine the sediment budget (sources, transport paths and sinks) and the seasonal variations in particulate fluxes. The major sources of sediment are the eroding cliffs surrounding the bay (1.0 × 10 6 m 3 y −1) and the seabed (6 × 10 6 m 3 y −1. There are no present-day sinks within the estuary; sediment is principally moved in suspension to the wider part of the Bay of Fundy. Residuals in sediment mass transport are strongly affected by storms. These disrupt the logarithmic longitudinal sediment concentration profile which is normally present, and cause sediment to be transported out of the estuary. Well-defined turbid ribbons occur which meander unpredictably through the sampling sites; estimates of sediment mass transport are thus dubious. 相似文献
10.
Summary In July and at the beginning of August 1997 a study was undertaken in the Gulf of Gdańsk and Pomeranian Bay to follow the
immediate effects of the flood which occurred within the Polish rivers — Wisla and Odra — drainage areas. The study included
measurements and observations of meteorological and hydrodynamic parameters, basic physico-chemical variables, certain persistent
organic pollutants as well as heavy metals and the level of sanitary pollution. The paper presents an overview of environmental
conditions in the bays, based on hydrochemical data, subsequent to the inflow of the flood crests. Results of biological investigations,
carried out solely in the Pomeranian Bay, on phytoplankton abundance, biomass, species composition and Zooplankton diversity
are also presented in the paper. The results of measurements were evaluated in comparison with long-term (1979–1996) monitoring
data and control measurements carried out in the last decade of August. It was found out that the impact of flood water was
restricted to internal areas of both bays and the negative environmental effects appeared only locally.
Umweltuntersuchungen in der Danziger und der Pommerschen Bucht nach der Sommerflut 1997
Zusammenfassung Im Juli und Anfang August 1997 fand in der Danziger und in der Pommerschen Bucht eine Untersuchung mit dem Ziel statt, die
unmittelbaren Auswirkungen der Flut, die sich in den Einzugsgebieten der polnischen Flüsse Weichsel und Oder ereignet hatte,
festzustellen. Die Untersuchung umfa?te Messungen und Beobachtungen meteorologischer, hydrodynamischer und physisch-chemischer
Parameter, bestimmter best?ndiger organischer Schadstoffe sowie Messungen von Schwermetallen und Messungen zum Grad der Verunreinigungen
durch Colibakterien. Die Arbeit gibt einen überblick über Umweltbeeintr?chtigungen in den betroffenen Gebieten im Anschlu?
an den Einstrom des Hochwassers basierend auf hydrochemischen Daten. Ergebnisse biologischer Untersuchungen in der Pommerschen
Bucht, speziell auf den Gehalt an Phytoplankton, Biomasse und deren Zusammensetzung sowie auf Zooplanktonvielfalt, werden
gezeigt. Die Ergebnisse der Messungen wurden im Vergleich mit Daten aus Langzeitreihen (1979–1996) und Kontrollmessungen in
der letzten Dekade des August bewertet. Es wurde festgestellt, da? der Einflu? des Hochwassers sich auf die inneren Gebiete
beider Buchten beschr?nkte und negative Umweltver?nderungen nur lokal auftraten.
相似文献
11.
The long-term effects of marine aggregate dredging on near-shore benthic assemblages are still largely unknown, despite a global increase in demand for, and extraction of, marine aggregates. This study assessed the state of recovery of polychaete assemblages in Botany Bay, temperate NSW, Australia, at sites dredged for aggregate material more than 10 years previously. Sedimentary and faunal samples were collected from impact sites in Botany Bay, and from reference sites in nearby Pittwater estuary. This study was based on, and included data from, a study conducted by the Australian Museum at the same sites in the 2 years following cessation of dredging. Abundance, species richness and evenness of polychaetes, as well as overall polychaete assemblage structure, were compared between localities over time. 相似文献
12.
Unusually warm and saline near-surface inflow was observed in the southern Bay of Biscay (Northeast Atlantic) in autumn–winter 2006–2007. These anomalies were swiftly entrained eastward through the Iberian Poleward Current flowing over the slope and shelf. Here, we present a quasi-synoptic three dimensional view of this event, which started as early as August 2006. In situ hydrological and Lagrangian measurements were used to describe its characteristics. The warm anomaly was surface intensified over the shelf, with surface temperature above 17 °C, a monthly anomaly over 1 °C compared to the 1994–2006 period. The saline anomaly was maximum around 100–200 m deep, over the upper slope, with values above 35.9 psu. Slope and shelf were seen to exhibit a complex structure of eastward (poleward) and westward (equatorward) currents. Maximum currents, observed near surface, over the upper slope in the eastern part of the Bay of Biscay, were determined to exceed 1.3 m s ?1. This current system eventually became unstable, thereby promoting strong exchange of properties between coastal and deep ocean. The event was coincident with abnormal southerly wind conditions west of Iberia in autumn 2006, and with the unusually warm autumn–winter weather over western Europe. A dynamical analysis relying on wind forcing west and north of Iberia is proposed. 相似文献
13.
The fate of polycyclic aromatic hydrocarbon (PAH) contamination in a mangrove swamp (Yi O) in Hong Kong after an oil spill accident was investigated. The concentrations and profiles of PAHs in surface sediments collected from five quadrats (each of 10 m×10 m) covering different degrees of oil contamination and the most contaminated mangrove leaves were examined in December 2000 (30 days after the accident) and March 2001 (126 days later). The concentrations of total PAHs in surface sediments ranged from 138 to 2135 ng g −1, and PAHs concentrations decreased with time. In the most contaminated sediments, total PAHs dropped from 2135 (30 days) to 1196 ng g −1 (120 days), and the decrease was smaller in less contaminated sediments. The percentage reduction in sediment PAHs over three months (44%) was less significant than that in contaminated leaves (85%), indicating PAH in or on leaves disappeared more rapidly. The PAH profiles were very similar in sediments collected from quadrats Q1 and Q2 with benzo[a]anthracene and pyrene being the most abundant PAH compounds, but were different in the other three quadrats. The proportion of the light molecular weight PAHs to total PAHs increased after three months, especially phenanthrene. Results suggest that physical and photo-chemical weathering (tidal washing and photo-oxidation) of crude oil in surface sediments and on plant leaves were important processes in the first few months after the oil spill. The PAH contamination in Yi O swamp came from both petrogenic and pyrolytic sources. The petrogenic characteristic in the most contaminated sediment was confirmed with high values of phenanthrene to anthracene ratio (>10) and low values of fluoranthene to pyrene ratio (0.3–0.4). 相似文献
14.
Comparison of groundwater quality data ten years apart and sampling of shallow level water and soil gas CO 2 indicates that the groundwaters below Birmingham are becoming more acidic. Six potential causes are considered: (1) rise of water level into the carbonate-poor upper levels of the sandstone aquifer; (2) oxidation of the Quaternary deposits overlying the aquifer; (3) inorganic acid spills; (4) other acidic recharge; (5) oxidation of inorganic pollutants; (6) degradation of industrial organic pollutants. Chemical and hydrogeological data suggest that (3), (5) and (6) are dominant in different parts of the city. The rate of fall in pH of 0.6 units over ten years is worrying with regard to increased solubility of toxic metals. 相似文献
16.
Intertidal animals and sediment from Kachemak Bay, Alaska were analysed to determine the concentrations of hydrocarbons. At Coal Point the herbivorous limpet Collisella pelta contained petroleum within its tissues while intertidal algae of the area have previously been shown to accumulate petroleum as a surface coating. At Coal Bay, a locality where both petroleum and coal are present, the filter feeding mussel Mytilus edulis contained petroleum hydrocarbons whereas the deposit feeding clam Macoma balthica contained an array of hydrocarbons suggesting detrital coal as the source. Animals higher in the food web including the gastropod Nucella lima and the urchin Strongylocentrotus droebachiensis showed no evidence of petroleum. All samples contained biogenic hydrocarbons of algal and planktonic origin. 相似文献
17.
The nearshore sediments in the Bay of Naples show a buildup of organic carbon and increased levels of lead, copper and chromium as a result of discharge of domestic and industrial waste water. Twenty to twenty-five square kilometres of bottom area have been contaminated by the buildup of anoxic muds with elevated heavy metal concentrations. 相似文献
19.
Sewage sludge was disposed of in Liverpool Bay for over 100 years. Annual amounts increased from 0.5 million tonnes per annum in 1900 to approximately 2 million tonnes per annum by 1995. Macrofauna and a suite of environmental variables were collected at a station adjacent to, and a reference station distant from, the disposal site over 13 years, spanning a pre- (1990-1998) and post- (1999-2003) cessation period. Univariate and multivariate analyses of the time-series data showed significant community differences between reference and disposal site stations and multivariate analyses revealed station-specific community development post-disposal. Temporal variability of communities collected at the disposal station post-cessation was higher than during years of disposal, when temporally stable dominance patterns of disturbance-tolerant species had established. Alterations of community structure post-disturbance reflected successional changes possibly driven by facilitation. Subtle faunistic changes at the Liverpool Bay disposal site indicate that the near-field effects of the disposal of sewage sludge were small and therefore could be considered environmentally acceptable. 相似文献
20.
An industrial accident resulted in a spillage of aldrin onto an estuarine beach at Hardys Bay, New South Wales. Samples of water and sediment were taken 3 weeks later to measure the level of contamination resulting from the spill. The abundances of some intertidal biota were also determined at the site of the spillage and in other uncontaminated areas. Three weeks after the spill, samples of water were not contaminated by aldrin but samples of sediment from the surface in the vicinity of the drain contained aldrin. In comparison to uncontaminated locations the abundances of crustacea were greatly reduced in the vicinity of the drain but abundances of polychaetes were not significantly different. The field data on the relative susceptibility of the two groups of animals agrees well with laboratory derived LC50 data for crustacea and polychaetes. The study suggests that degree of contamination of water and sediment may not always be an accurate reflection of acute impact on biota, and that different components of the biota can show different reactions to the presence of a toxic chemical. 相似文献
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