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1.
Jobos Bay, located on the southeastern coast of Puerto Rico, contains a variety of habitats including mangroves, seagrass meadows, and coral reefs. The watershed surrounding the bay includes a number of towns, agricultural areas, and the Jobos Bay National Estuarine Research Reserve (NERR). Jobos Bay and the surrounding watershed are part of a Conservation Effects Assessment Project (CEAP), involving the Jobos Bay NERR, the US Department of Agriculture, and the National Oceanic and Atmospheric Administration (NOAA) to assess the benefits of agricultural best management practices (BMPs) on the terrestrial and marine environments. As part of the Jobos Bay CEAP, NOAA collected sediment samples in May 2008 to characterize over 130 organic chemical contaminants. This paper presents the results of the organic contaminant analysis. The organic contaminants detected in the sediments included polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls, and the pesticide DDT. PAHs at one site in the inner bay near a boat yard were significantly elevated; however, all organic contaminant classes measured were below NOAA sediment quality guidelines that would have indicated that impacts were likely. The results of this work provide an important baseline assessment of the marine environment that will assist in understanding the benefits of implementing BMPs on water quality in Jobos Bay.  相似文献   

2.
The distribution of trace metals (spatial and temporal) and sedimentary fractions were investigated to identify the concentrations and sources of trace metals within Kogarah Bay, NSW, Australia. A total of 59 surface sediments and six subsurface samples from core of the sediment were collected. The contamination factor and pollution load index indices used to evaluate environmental effects of trace metals. The study area was found to be uncontaminated with Cr and Ni, moderately contaminated with As and considerably contaminated with Cu, Zn and Pb. The concentrations of Cr and Ni were below both effect range low and effect range median, while As, Cu, Zn and Pb were slightly above effect range low. The highest concentrations of these trace metals such as Cu, Zn and Pb were found in the north, northwest and southeast of the bay, close to discharge points, stormwater outlets and around boatyards and watercrafts. The spatial distributions of metals were strongly related to muddy particles and organic matter. The temporal sediments of metals declined with increased sediment depth, which reflects accumulation of trace metals since European settlement in this area. Furthermore, the source of the trace metals was found to be stormwater outlets, gasoline fumes, boatyards and other human activities.  相似文献   

3.
The contents of heavy metals (Fe, Mn, Pb, Cu, Cd, and Hg) dissolved in water and suspended solids of Gökova Bay—partly and fully sampled in 2005 and 2006, respectively—are quite higher than the average values encountered in uncontaminated sea water. The high concentrations are associated with terrestrial inputs from the mining zones and anthropogenic (domestic + industrial) sources. Moreover, the distribution of Fe and Cu is affected by primary production because these elements function as nutrients in biological activities. The Cr, Ni, and Fe concentrations of surface sediments are above the shale average. The Cr and Ni contents of surface sediments representative of river mouths strongly correlate with total phosphorus contents. In a sulfide-poor environment, Pb and Cu were concentrated at a higher ratio in surface sediments than Cd, probably due to higher stabilities of their surface complexes with amorphous iron oxides and clay minerals existing as major components in the sediments. The exceptional enrichment of Zn may be attributed to double oxide formation with amorphous iron oxides in sediments. The high metal values are most probably caused by terrestrial inputs from anthropogenic sources and the mining zones at the southeast part of the bay. The Al, Mn, Pb, Cu, Zn, and Hg contents are below the shale average. The low values have possibly originated from the coarse-grained sandy sediments having a low affinity for metals. There are no distinct differences in the metal distributions in water and suspended matter between the years 2005 and 2006 in the bay, probably due to low sedimentation rates.  相似文献   

4.
Spatial and temporal variations of sediment quality in Matanzas Bay (Cuba) were studied by determining a total of 12 variables (Zn, Cu, Pb, As, Ni, Co, Al, Fe, Mn, V, CO3 2?, and total hydrocarbons (THC). Surface sediments were collected, annually, at eight stations during 2005–2008. Multivariate statistical techniques, such as principal component (PCA), cluster (CA), and lineal discriminant (LDA) analyses were applied for identification of the most significant variables influencing the environmental quality of sediments. Heavy metals (Zn, Cu, Pb, V, and As) and THC were the most significant species contributing to sediment quality variations during the sampling period. Concentrations of V and As were determined in sediments of this ecosystem for the first time. The variation of sediment environmental quality with the sampling period and the differentiation of samples in three groups along the bay were obtained. The usefulness of the multivariate statistical techniques employed for the environmental interpretation of a limited dataset was confirmed.  相似文献   

5.
为探究燃煤电厂周边大气环境中重金属的污染特征与来源,对广东某山区燃煤电厂周边地区环境和污染源的重金属进行测定,分析其污染特征,采用因子分析法和Pb同位素示踪法对环境中的重金属进行来源解析。结果表明,研究区域室内积尘中重金属浓度水平明显高于土壤重金属,污染空间分布与当地气象条件相关。环境空气TSP中重金属主要来自2个污染源,Cd、Pb、As主要来自电厂燃煤,Ca、Mn、Al、Mg主要来自土壤扬尘。TSP、降尘、积尘样品所含的Pb均与电厂采集的煤、炉渣、粉煤灰样品所含的Pb具有同源性,与其他污染源同源性不明显,说明研究区域大气中Pb污染主要来自电厂燃烧所排放的烟尘,其他污染源影响不大。  相似文献   

6.
In this study, bioaccumulation of the heavy metals (Fe, Zn, Cd) in the liver, gill, gonad and muscle tissues of Dicentrarchus labrax, Mugil cephalus and Sparus aurata were investigated seasonally. Camlik is the important fisheries lagoon located in The Iskenderun Bay, Mediterranean coast of Turkey. Due to heavy industrial and agricultural activities in the region, the bay has the polluted coastal waters of Turkey. Therefore, the levels of cadmium, zinc, iron were determined in the muscle in each species because of its importance for human consumption and also the liver, gill, gonad were analysed since these organs tend to accumulate metals. Heavy metal levels were found generally higher in the liver and gill than the gonad and muscle tissues in three species; the levels of all metals in a given tissue were generally higher in Mugil cephalus than the other two species. Data collected in this study suggest that Camlik lagoon is affected by a relatively metal pollution. The concentrations of Zn concentrations in the muscle tissues exceeded the acceptable levels for a food source for human consumption and other metals in the edible parts of the investigated fish were in the permissible safety levels for human uses.  相似文献   

7.
Twenty-one surface sediment samples were collected from Akkaya Dam. Heavy metal concentrations (Mo, Cu, Pb, Zn, Ni, Co, Mn, Fe, Cr, As, V and Cd), grain size, organic carbon and carbonate contents were studied in order to assess the extent of environmental pollution and to discuss the origin of these contaminants in sediments of dam. The sediments in the study area are mostly very fine sands. However, mud was observed in the northeast of the dam. Sediment pollution assessment was carried out using enrichment factor. The calculation of enrichment factors showed that Mo is depleted by 1.0 whereas Cu, Pb, Zn, Ni, Co, Mn, As, V, Cr and Cd are enriched by 3, 5.4, 7, 2.7, 2.2, 3.4, 42.3, 2.1, 1.8 and 7.2, respectively. Relatively high concentrations heavy metals occurred in north (textile industry area) and east (Karasu River) due to enrichment controlled by anthropogenic wastes. The results of correlation analysis show low–medium positive and negative correlations among metals, grain size, carbonate contents and organic carbon and indicate that heavy metals in sediments of the Akkaya Dam have different anthropogenic sources.  相似文献   

8.
The geochemistry of the suspended particulate matter (SPM) collected during the monsoon was determined to identify the sources of SPM and to understand the physicochemical processes in the Mandovi and Zuari river estuaries. The concentrations of SPM decrease seaward in both estuaries, but are relatively high at bay stations. Kaolinite is the most dominant clay mineral in the upstream of both rivers. Smectite increases seaward in both estuaries and is abundant in the bay. Upstream stations of Mandovi, where ore deposits are stored on the shore, exhibit high Fe, Mn, total rare earth elements (∑REE), and middle REE- and heavy REE-enriched patterns. Channel stations of both estuaries exhibit middle REE- and light REE-enriched patterns, which gradually changed seaward to middle REE- and heavy REE-enriched patterns. Canal stations exhibit the highest concentrations of major and trace metals. High metal/Al ratios occur at stations in the upstream of Zuari and at the confluence of canals in the Mandovi estuary. Enrichment factors of metals indicate that Mn is significantly polluted while other metals are moderately polluted. The δ 13C and δ 15N of organic matter indicate that the terrigenous organic matter at the upstream is diluted seaward by marine organic matter. Organic matter at bay stations is largely marine and altered-type. The compositions of SPM are controlled by the particulates from ore dust, the geology of the drainage basins, and the physicochemical processes in the estuaries. Particulates resuspended from the bay are dominated by ore dust, which are advected into the channels of both estuaries during the lull periods of the monsoon.  相似文献   

9.
长江下游典型滨海地区农业土壤重金属污染特征   总被引:1,自引:0,他引:1  
为揭示长江下游滨海地区农业土壤重金属污染状况,以滨江临海的南通市为例,网格化布点,采集表层农业土壤样品共计334个,对其重金属Cu、Pb、Cr、As、Hg含量进行了测定分析.结果表明,研究区域表层农业土壤中各重金属含量均已超过其背景值,且以Pb污染最为严重;区域性差异较大,以滨海的如东、海门、启东污染最为严重,且以海门、启东As含量最高;各重金属间相关性不显著,来源途径不止一种.从而提出南通市农业土壤重金属污染的防治应立足于防重于治的方针,着重滨海地区,以Pb、As污染源为主,并对污染土壤进行修复.  相似文献   

10.
Metal concentrations were determined in surface sediments and transplanted mussels in a shallow semi-enclosed bay, Pagassitikos Gulf, Aegean Sea. Cu, Zn, Pb, Hg, and As levels in sediments were enriched close to point sources of pollution, i.e., Volos Port and cement plant. Fe, Mn, Cr, and Ni spatial distributions in sediments were rather uniform with increasing concentrations towards deeper sites, suggesting natural enrichment, whereas levels found in the port, although elevated, were not the highest in the study area. Spatial variations in concentrations of most metals in mussels transplanted nearshore were generally in accordance to those in sediments, with the highest Fe, Mn, Cr, Ni, and Cu levels in the port and the highest Hg levels close to the cement plant. Concentrations of metals in sediments and transplanted mussels were comparable to those reported in Mediterranean areas. Results indicate that pollution point sources contribute to anthropogenic metal enrichment in the study area.  相似文献   

11.
Mining has been carried out upstream of Miyun Reservoir, Beijing, for several decades, and has caused metal emissions to the environment, threatening human health. We conducted a soil survey to assess metal contamination in this area and to determine distribution of heavy metals in the particle size. We attempted to determine the possible sources of the metals and the significance of metals in the fine particle fractions to soil risk assessments. Thirty-four soil samples were collected, and eight samples were partitioned into seven size fractions. Most of the metal concentrations in the soils were higher than the background levels in Beijing, and the metal concentrations and total organic matter (TOC) contents generally increased as the particle size decreased. Each metal except Hg significantly positively correlated with the TOC. The metals in the coarse-grained soils were mainly derived from parent materials, but the metals in the fine fractions were mostly anthropogenic. Statistical analyses showed that there were three metal sources: Cd, Cu, Hg, Pb, and Zn had anthropogenic sources; Co, Cr, Ni, and V had mixed anthropogenic and natural sources; and As and Be had natural sources. The trace metals were primarily in the clay and fine silt fractions, and they might pose health risks through the inhalation of resuspended soil particles (PM10 and PM2.5). The elevated accumulation factors, enrichment factors, and ecological risk indices for the metals in the fine fractions suggest that risk assessments should be based on the fine particle size.  相似文献   

12.
In this study, the levels of natural and anthropogenic metal contamination (aluminum (Al), iron (Fe), manganese (Mn), arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn)) in surface sediments of three harbors along the Iranian coast of Gulf of Oman were examined and reported for the first time. Effect of grain size, mineralogy, normalization technique using Fe concentrations, and different sediment quality guidelines were discussed. Data from the harbors were compared with other harbors worldwide. Sediments inside the harbors are characterized by moderate and high levels of pollution by trace metals Cu (12–287 μg/g), Pb (11–1,780 μg/g), Zn (38–547 μg/g), Cr (70–2,370 μg/g), and Ni (31–116 μg/g). However, As and Cd did not show considerable pollution inside and outside the harbors. Considering that there is no industrial activity around the study harbors, the major sources of contamination in the harbors are repairing, fueling, greasing, and painting of fishing ships and boats. Mineralogy of sediments in the study area as well as trace metal concentration in reference samples taken from onshore geological units confirmed that natural inputs of Cd, Cu, Pb, and Zn in the harbors are very low while most of Ni and Cr contamination in the study area comes from erosion of ophiolitic mélange units at the North of Makran mountains.  相似文献   

13.
The article presents the distribution and enrichment of acid-leachable heavy metals (ALHMs) Cu, Zn, Pb, Cr, Mn, and Fe in the intertidal sediments collected from Quanzhou Bay, southeast coast of China. The contents of ALHMs along with sediment texture, total organic carbon, S2???, and CaCO3 in surface sediments were analyzed to identify the input of heavy metals from various sources. The enrichment of ALHMs in the sediments is mainly attributed to the intense industrial activities around Quanzhou Bay and to the serried activities of intertidal breed aquatics along the seacoast. The results also illustrate the association between the ALHMs with the finer fractions, organic matter, and Fe oxyhydroxides in the sediments. The above results were very supported by the multivariate statistical analyses, including correlation, principal component analysis, and hierarchical clustering analysis. Comparative results of ALHMs in the intertidal sediments from Quanzhou Bay with those in other domestic bays and estuaries indicate that the study area has been enriched with heavy metals, especially with Zn, Cu, and Pb, during the past few decades. The results of the present study suggest that the authorities should pay attention to the current status and take some measures to control the heavy metal pollution in the study area.  相似文献   

14.
Inland pollution sources of Doam bay were investigated from August to October in 2013. A total of 210 sources including rivers, streams, domestic, agricultural and industrial discharge points were identified along the coast, including 32 sources that had outflow. Agricultural sources were the largest inland pollution sources (139, 66.2%). Fecal coliform concentrations were measured. These data were combined with water discharge data to determine daily loads of pollutants discharged from each source into the bay. Fecal coliform concentrations were the highest in domestic discharges. However, they only had slight influence because their discharge volume was small. The most significant pollution source was Tamjin River (St.85) due to large amount of discharge volume. The influence of St.85 reached almost half of Doam bay. Fecal coliform levels of streams increased after rainfall, but decreased overtime. Domestic pollution sources were not affected upon rain event.  相似文献   

15.
Most wastewater from the city of Chetumal is discharged into the adjoining bay without treatment through a pluvial sewer system. The bay also receives a high volume of vegetal organic material from the River Río Hondo. The average of biochemical oxygen demand (BOD) was 32.26 mg l-1, it was low compared with other reports and should be indicative of self-depuration processes in Chetumal Bay. In the area most used by the public for recreational and fishing activities, concentrations of fecal coliforms above the limit established by Mexican Legislation were shown. The border between Mexico and Belize is Chetumal Bay, which recently was declared a protected area for manatees.  相似文献   

16.
This study presents an integrated k-means clustering and gravity model (IKCGM) for investigating the spatiotemporal patterns of nutrient and associated dissolved oxygen levels in Tampa Bay, Florida. By using a k-means clustering analysis to first partition the nutrient data into a user-specified number of subsets, it is possible to discover the spatiotemporal patterns of nutrient distribution in the bay and capture the inherent linkages of hydrodynamic and biogeochemical features. Such patterns may then be combined with a gravity model to link the nutrient source contribution from each coastal watershed to the generated clusters in the bay to aid in the source proportion analysis for environmental management. The clustering analysis was carried out based on 1 year (2008) water quality data composed of 55 sample stations throughout Tampa Bay collected by the Environmental Protection Commission of Hillsborough County. In addition, hydrological and river water quality data of the same year were acquired from the United States Geological Survey's National Water Information System to support the gravity modeling analysis. The results show that the k-means model with 8 clusters is the optimal choice, in which cluster 2 at Lower Tampa Bay had the minimum values of total nitrogen (TN) concentrations, chlorophyll a (Chl-a) concentrations, and ocean color values in every season as well as the minimum concentration of total phosphorus (TP) in three consecutive seasons in 2008. The datasets indicate that Lower Tampa Bay is an area with limited nutrient input throughout the year. Cluster 5, located in Middle Tampa Bay, displayed elevated TN concentrations, ocean color values, and Chl-a concentrations, suggesting that high values of colored dissolved organic matter are linked with some nutrient sources. The data presented by the gravity modeling analysis indicate that the Alafia River Basin is the major contributor of nutrients in terms of both TP and TN values in all seasons. With this new integration, improvements for environmental monitoring and assessment were achieved to advance our understanding of sea-land interactions and nutrient cycling in a critical coastal bay, the Gulf of Mexico.  相似文献   

17.
Industrial and weathering inputs of Cd and Zn to the Sepetiba Bay and basin were assessed, based on production parameters obtained from local environment and industry authorities, and literature data. The results are compared with similar evaluations from other coastal regions and field data obtained in measuring Zn and Cd transport by rivers, direct run-off and atmospheric deposition in the region. Cadmium and zinc inputs to the bay increased by three orders of magnitude relative to pre-industrial fluxes and presently reach up to 1.6 and 180 tonnes per year for Cd and Zn, respectively, which represents a large input-to-area ratio, and explains the high concentration of these metals previously reported in the estuarine biota and sediments of Sepetiba Bay. Industrial activities, mainly metallurgical and chemical, comprise 94% and 84% of the total Cd and Zn inputs to the Bay. This figure identifies the point sources as being responsible for the environmental contamination and for regional poisoning risks.  相似文献   

18.
In the last three decades, the industrial and human activities in the coastal area of Saudi Arabia have increased dramatically and resulted in the continuous invasion of different types of pollutants including heavy metals. Seven sediment cores were collected from three major industrialized areas; Jeddah, Rabigh and Yanbu, along the coast of Saudi Arabia to determine the spatial and temporal distribution of metals and to assess the magnitude of pollution and their potential biological effects. Sediments were analyzed for texture, calcium carbonate contents, organic matter and metals (Al, Fe, Mn, Cd, Cr, Cu, Ni, Pb and Zn). Some metals like, Cr, Mn, Ni and Zn, were enriched in the upper 15 cm of core samples (recent deposition of sediments). Cadmium concentrations showed high fluctuations with depth and reverse pattern to that for Al, Fe and Mn which indicated land based sources of this element to the studied areas. Elevated concentrations of lead were recorded in the bottom layers of cores in Jeddah that indicated the most dramatic increase in usage of gasoline in early 1970s. The calculated contamination factors (CF's) were found in the following sequences: Cd > Pb > Ni > Cu > Zn > Cr > Mn for all studied areas. Results of Pollution Load Index (PLI) revealed that Jeddah is the most polluted area, followed by Rabigh while Yanbu is the least contaminated area. Except for Ni, the concentrations of most metals in the majority of sediment samples were believed to be safe for living organisms. As no data were available on the concentration of metals in core sediments in the coastal area of Saudi Arabia, the results of this study would serve as a baseline against which future anthropogenic effects can be assessed.  相似文献   

19.
Hurricanes are relatively frequent ecological disturbances that may cause potentially long-term impacts to the coastal environment. Hurricane Katrina hit the Mississippi Gulf Coast in August 2005, and caused a storm surge with the potential to change the trace element content of coastal surface sediments. In this study, surface estuarine and marine sediments were collected monthly following the storm from ten sites along the Mississippi Gulf Coast (Mobile Bay, Grand Bay Bayous Heron and Cumbest, Pascagoula, Ocean Springs, Biloxi Gulf, Back Biloxi Bay, Gulfport Gulf, Gulfport Courthouse Rd, and Gulfport Marina). Concentrations of V, Cr, Mn, Fe, Co, Ni, Zn, As, Cd, and Pb were measured by inductively coupled plasma–mass spectrometry to evaluate their temporal and spatial variations in the year following Hurricane Katrina. Sediments were characterized by pH, particle size distribution and total carbon and nitrogen content. Trace element contents of the sediments were determined in both <2 mm and <63 μm grain size fractions. Results revealed no significant temporal and spatial variability in trace element concentrations, in either size fraction. Potential ecological risk of the sediments was assessed by using NOAA SQuiRTs’ guideline values; most concentrations remained below probable adverse effects guidelines to marine organisms suggesting that trace elements redistributed by Hurricane Katrina would not cause an adverse impact on resident organisms. Instead, the concentrations of trace elements were site-dependent, with specific contaminants relating to the use of the area prior to Hurricane Katrina.  相似文献   

20.
The concentrations of trace metals (Cu, Zn, Mn, Ni, and Fe) from suspended particulate matter (SPM) and biota in Izmir Bay (Eastern Aegean Sea) were studied in order to evaluate the environmental impact of the anthropogenic metals before building of Wastewater Treatment Plant. SPM samples were collected in wet and dry periods from Izmir Bay. Metal concentrations in SPM (Cu, 0.36–2.19; Mn, 0.07–11.3; Ni, 0.43–7.81; Zn, 7.33–269; Fe, 1.00–266 μgdm − 3) were comparable to those reported for other moderately polluted bays. Maximum metal concentrations in SPM were observed during summer season. SPM metal concentrations displayed a clear spatial trend with values increasing with proximity to urban centers. Cu and Zn concentrations in SPM were especially high in the inner bay. SPM were found to be contaminated by Zn. The vertical profile of Mn, Zn, and Ni concentrations in SPM had a maximal value at the upper layer and decreased to minimal value at the bottom layer of the inner bay in summer, in contrast to the observed pattern of Fe and Cu. Maximum Cu concentrations were obtained in Penaeus kerathurus. Also, maximum Zn and Fe concentrations were found in Mytilus galloprovincialis. Relatively high Cu levels were found in Sardina pilcardus and Mullus barbatus than other fish species. Besides, Cu levels were lower in Diplodus annularis and Merluccius merluccius. Finally, metal levels in biota tissues were lower than the limits of European Dietary Standards and Guidelines.  相似文献   

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