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Stormwater runoff plumes in the Southern California Bight: A comparison study with SAR and MODIS imagery
2017
Holt, Benjamin | Trinh, Rebecca | Gierach, Michelle M.
Stormwater runoff is the largest source of pollution in the Southern California Bight (SCB), resulting from untreated runoff and pollutants from urban watersheds entering the coastal waters after rainstorms. We make use of both satellite SAR and MODIS-Aqua ocean color imagery to examine two different components of runoff plumes, the surface slick and the sediment discharge. We expand on earlier satellite SAR studies by examining an extensive collection of multi-platform SAR imagery, spanning from 1992 to 2014, that provides a more comprehensive view of the plume surface slick characteristics, illustrated with distribution maps of the extent and flow direction of the plumes. The SAR-detected surface plumes are compared with coincident rain and runoff measurements, and with available measured shoreline fecal bacteria loads. We illustrate differences in the detection of SAR surface plumes with the sediment-related discharge plumes derived from MODIS imagery. A conceptual satellite stormwater runoff monitoring approach is presented.
显示更多 [+] 显示较少 [-]Screening for microplastics in sediment, water, marine invertebrates and fish: Method development and microplastic accumulation
2017
Karlsson, Therese M. | Vethaak, A Dick | Almroth, Bethanie Carney | Ariese, Freek | van Velzen, Martin | Hassellöv, Martin | Leslie, Heather A.
Measurements of microplastics in biota and abiotic matrices are key elements of exposure and risk assessments for this emerging environmental pollutant. We investigated the abundance of microplastics in field-collected biota, sediment and water. An improved sediment extraction method, based on density separation was developed. For analysis of microplastics in biota we found that an adapted enzymatic digestion protocol using proteinase K performed best, with a 97% recovery of spiked plastic particles and no observed degradation effects on the plastics in subsequent Raman analysis. Field analysis revealed that 8 of 9 tested invertebrate species from the North Sea and 68% of analyzed individuals of brown trout (Salmo trutta) from the Swedish West Coast had microplastics in them. Based on the number of plastic particles per kg d.w. the microplastic concentrations found in mussels were approximately a thousand-fold higher compared to those in sediment and surface water samples from the same location.
显示更多 [+] 显示较少 [-]Impacts of Regional Transport on Particulate Matter Pollution in China: a Review of Methods and Results
2017
Sun, Jinjin | Huang, Lin | Liao, Hong | Li, Jingyi | Hu, Jianlin
China has been suffering serious particulate matter (PM) pollution in recent decades. Local emission and regional transport both contribute to PM pollution. Determining the contributions of local emissions vs. regional transport to PM concentrations is crucial in making effective PM control policies. This paper reviews the recent research on the contributions of regional transport to PM pollution in four regions in China, i.e., the northern China, eastern China, southern China, and the western China, respectively. The major findings include (1) HYSPLIT is the most popular methods in studies in all regions and often is used in combination with the CA, PSCF, and CWT techniques to investigate the transport pathways and source origins; (2) during the relatively polluted period, transport contributes over 50% of the PM concentrations in Beijing, Shanghai, Hangzhou, Guangzhou, Hong Kong, and Chengdu. Regional transport is important for PM pollution in major cities of China; and (3) regional transport exhibits clear seasonal variations and long term trends. The findings have important implication for emission control programs in these regions.
显示更多 [+] 显示较少 [-]Trends in nitrogen isotope ratios of juvenile winter flounder reflect changing nitrogen inputs to Rhode Island, USA estuarine systems
2017
Pruell, Richard J. | Taplin, Bryan K. | Miller, Kenneth M.
Nitrogen isotope ratios (δ15N) in juvenile winter flounder, Pseudopleuronectes americanus, were used to examine changes in nitrogen inputs to several Rhode Island, USA estuarine systems. Fish were collected over two three-year periods with a ten-year interval between sampling periods (2002–2004 and 2012–2014). During that interval numerous changes to nutrient management practices were initiated in the watersheds of these estuarine systems including the upgrade of several major wastewater treatment facilities that discharge to Narragansett Bay, which significantly reduced nitrogen inputs. Following these reductions, the δ15N values of flounder in several of the systems decreased as expected; however, isotope ratios in fish from upper Narragansett Bay significantly increased. We believe that low δ15N values measured in 2002–2004 were related to concentration-dependent fractionation at this location. Increased δ15N values measured between 2012 and 2014 may indicate reduced fractionation or that changes in wastewater treatment processes altered the nitrogen isotopic ratios of the effluents.
显示更多 [+] 显示较少 [-]Polycyclic aromatic hydrocarbons (PAHs) in wild marine organisms from South China Sea: Occurrence, sources, and human health implications
2017
Ke, Chang-Liang | Gu, Yang-Guang | Liu, Qi | Li, Liu-Dong | Huang, Hong-Hui | Cai, Nan | Sun, Zhi-Wei
Concentrations of 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) were measured in 15 marine wild organism species from South China Sea. The concentration (dry weight) of 16 PAHs ranged from 94.88 to 557.87ng/g, with a mean of 289.86ng/g. The concentrations of BaP in marine species were no detectable. The composition of PAHs was characterized by the 2- and 3-ring PAHs in marine species, and NA, PHE and FA were the dominant constituents. PAHs isomeric ratios indicated PAHs mainly originated from grass, wood and coal combustion, and petroleum. The human health risk assessment based on the excess cancer risk (ECR) suggested the probability of PAHs posing carcinogenic risk to human beings with consumption of marine organisms were negligible (probability<1×10−6).
显示更多 [+] 显示较少 [-]Chemical composition of two mineralogically contrasting Arctic bivalves' shells and their relationships to environmental variables
2017
Iglikowska, A. | Bełdowski, J. | Chełchowski, M. | Chierici, M. | Kędra, M. | Przytarska, J. | Sowa, A. | Kukliński, P.
The main goal of this study was to determine the concentrations of trace elements in the mineralogically contrasting shells of two Arctic bivalves: Chlamys islandica and Ciliatocardium ciliatum. Aragonite shells seem to be more susceptible to the binding of metal ions, which is most likely a result of their crystal lattice structure. We suggest that less biologically controlled aragonite mineralization tends to incorporate more metal impurities into the crystal lattice in waters with a lower pH, where metal ions are more available. Higher concentrations of impurities may further increase the lattice distortion causing lower crystal lattice stability and higher susceptibility to dissolution. Calcitic shells seem to be less prone to bind metal ions than aragonite shells most likely because under strict biological control, the uptake of ions from ambient seawater is more selective; thus, the final crystal lattice is less contaminated by other metals and is more resistant to dissolution.
显示更多 [+] 显示较少 [-]Mercury concentrations in dusky grouper Epinephelus marginatus in littoral and neritic habitats along the Southern Brazilian coast
2017
Condini, Mario V. | Hoeinghaus, David J. | Roberts, Aaron P. | Soulen, Brianne K. | Garcia, Alexandre M.
Our study incorporated a comprehensive suite of parameters (i.e., body size, age, diet and trophic position) to investigate mercury concentration in dusky groupers Epinephelus marginatus. This study was carried out in rocky bottoms in littoral and neritic habitats along the Southern Brazilian coast. We also determined spatial variation in mercury concentrations in individuals inhabiting both zones, which may provide insights into how dietary differences or potential pollution sources affect bioaccumulation. A total of 244 dusky groupers was analyzed to determine total mercury concentrations. Our study revealed that when considering similar body sizes, individuals inhabiting littoral rocky habitats had higher concentrations of mercury probably due to proximity to pollution sources associated with human activities in the estuary and its drainage basin. Furthermore, large individuals (>650mm and >8years old) showed mercury contamination levels that are potentially harmful for this endangered fish species and above the acceptable limits for human consumption.
显示更多 [+] 显示较少 [-]Assessment of metallic trace elements in the muscles and fins of four landed elasmobranchs from Kuala Terengganu Waters, Malaysia
2017
Ong, Meng Chuan | Gan, Shi Ling
A study had been carried out to determine Cu, Zn, Cd, Hg and Pb concentrations in the muscle and fins of four elasmobranchs species namely spot-tail sharks, milk sharks, whitespotted bamboo sharks and whitespotted guitarfish from Pulau Kambing LKIM Fishery Complex, Kuala Terengganu, Malaysia. Zinc level was found to have the highest concentration whereas Cd had the lowest concentration in both organs. By comparing both organs, metals concentrations in fins of all elasmobranchs species were higher than muscle. Result obtained was compared with the guidelines set by Malaysian Food Regulation and the provisional tolerable weekly intake was also determined. Current study recommends that the muscle of whitespotted bamboo shark from Kuala Terengganu Waters is likely not to be consumed due to it exceeded the allowable consumption guideline. Finding of this paper is very useful as it provides the baseline data on the pollution status of elasmobranchs in Kuala Terengganu Waters.
显示更多 [+] 显示较少 [-]Spatial and temporal variations of heavy metals in marine sediments from Liaodong Bay, Bohai Sea in China
2017
Liu, Liang | Wang, Lijun | Yang, Zhengxian | Hu, Katherine Fan | Ma, Minghui
An integrated analysis has been carried out using surface sediment monitoring data in order to characterize the spatial distributions and temporal trends of heavy metals within ten years from 2004 to 2013 in the entire Liaodong Bay. Hg, Cd and As were predominant contaminants with their median concentrations of 0.04–0.15, 0.01–0.65, and 1.80–30.3mg/kg respectively. Both areas and levels of Cu and Pb contamination were low. Cd contents exhibited an obvious decreasing trend and As presented a similar law during these 10years. Further, emissions from different sources were analyzed to identify the possible reasons contributing to the metal pollution. Dramatic descending of waste water might be the top reason for Cd and As variations. Local flue gases and smoke emissions might not be the main sources contributing to Hg pollution, whereas atmospheric deposition at a larger scale was supposed to be the leading factor.
显示更多 [+] 显示较少 [-]Macrobenthic communities in Hong Kong waters: Comparison between 2001 and 2012 and potential link to pollution control
2017
Wang, Zhi | Leung, Kenneth M.Y. | Li, Xinzheng | Zhang, Tong | Qiu, Jian-Wen
Macrobenthic communities in 2001 and 2012 were compared across the marine environment of Hong Kong based on sediment grab samples collected from 28 stations. CLUSTER analysis showed in both surveys that the stations could be divided into four groups at 20% faunal similarity. However, there were notable changes in the macrobenthic community structure between 2001 and 2012 in three focal areas of pollution control (i.e., Victoria Harbour, Deep Bay and Tolo Harbour). The potential link between macrobenthos and pollution abatement measures, and the contributions of environmental conditions to the differential responsiveness of macrobenthos were explored. Notably, a reduction in nutrient input to the eastern part of Victoria Harbour might have led to recovery of benthic communities therein.
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