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Long-term seafloor monitoring at an open ocean aquaculture site in the western Gulf of Maine, USA: Development of an adaptive protocol Полный текст
2014
Grizzle, R.E. | Ward, L.G. | Fredriksson, D.W. | Irish, J.D. | Langan, R. | Heinig, C.S. | Greene, J.K. | Abeels, H.A. | Peter, C.R. | Eberhardt, A.L.
The seafloor at an open ocean finfish aquaculture facility in the western Gulf of Maine, USA was monitored from 1999 to 2008 by sampling sites inside a predicted impact area modeled by oceanographic conditions and fecal and food settling characteristics, and nearby reference sites. Univariate and multivariate analyses of benthic community measures from box core samples indicated minimal or no significant differences between impact and reference areas. These findings resulted in development of an adaptive monitoring protocol involving initial low-cost methods that required more intensive and costly efforts only when negative impacts were initially indicated. The continued growth of marine aquaculture is dependent on further development of farming methods that minimize negative environmental impacts, as well as effective monitoring protocols. Adaptive monitoring protocols, such as the one described herein, coupled with mathematical modeling approaches, have the potential to provide effective protection of the environment while minimize monitoring effort and costs.
Показать больше [+] Меньше [-]Assessment of traffic-generated gaseous and particulate matter emissions and trends over Delhi (2000–2010) Полный текст
2014
Sindhwani, Rati | Goyal, Pramila
Development and urbanization over the past decade has led to rapid increase in the population of Delhi, the metropolitan city of India. Consequently, there has been a tremendous increase in the number of vehicles, which are causing very high levels of air pollution. Vehicular emissions are becoming most predominant source of air pollution in Delhi. An annual emission inventory of road transport emissions of pollutants including carbon monoxide (CO), methane (CH4), nitrogen oxides (NOX), sulfur dioxide (SO2), volatile organic compounds (VOCs), particulate matter (PM10), lead (Pb) and hydrocarbon (HC), organic carbon (OC) and black carbon (BC) has been developed (for the period 2000–2010), for the Delhi region. Emissions have been estimated using emission factor and activity–based approach recommended by IPCC. The emissions of CO and NOX have increased nearly 77% and 29% respectively over 2000 to 2010, whereas contribution of SO2 has greatly reduced (~21%) due to phasing out of diesel driven buses and implementation of Bharat Stage–III norms to commercial vehicles. An appreciable increase in NOX emissions has been observed after 2005, which might be due to the use of CNG fuel. Emissions of PM10, OC and BC have decreased in 2001 and 2002, however these are continuously increasing after 2002 due to rapid rise in the annual rate of growth of registered vehicles in Delhi. Two wheelers (2Ws), which constitute 60% of total registered vehicles, have been found to be major contributors towards emissions of the pollutants considered in the present study.
Показать больше [+] Меньше [-]The 2013 severe haze over the Southern Hebei, China: PM2.5 composition and source apportionment Полный текст
2014
Wei, Zhe | Wang, Li–Tao | Chen, Ming–Zhang | Zheng, Yan
PM2.5 samples were collected and analyzed for the first time in Handan City, which was listed in the top 4 polluted cities in China, during December 2012 to January 2013 when the record–breaking severe haze pollution happened. Positive Matrix Factorization method (PMF) was applied to understand major sources to the severe haze pollution over this city. The daily average concentration of PM2.5 was 160.1μg m–3, which was 2.1 times of the National Ambient Air Quality Standards of China (Class II, Annual Average Level) for daily average PM2.5 of 75μg m–3. SO42– was the most abundant ion (15.4%), followed by NH4+ and NO3–. They accounted for 39.5% of PM2.5. Eight factors were identified by positive matrix factorization (PMF) model. The major sources were coal combustion source (25.9%), secondary source (21.8%), industry source (16.2%), Ba, Mn and Zn source (12.7%), motor vehicle source (7.7%), road dust source (10.9%), K+, As and V source (6.3%) and fuel oil combustion source (2.5%).The mean value of extinction coefficient (Bext) was 682.1Mm–1 and the largest contributor to Bext was ammonium sulfate with the mean value of 221.0Mm–1, accounted for 32.4% of the Bext.
Показать больше [+] Меньше [-]Are changes in the structure of nematode assemblages reliable indicators of moderate petroleum contamination? Полный текст
2014
Leite, Daniel Silva | Sandrini-Neto, Leonardo | Camargo, Manuela Zeglin | Thomas, Micheli Cristina | Lana, Paulo C.
This study assesses through a multiple before-after-control-impact (MBACI) design the effects of diesel oil on the structure of nematode assemblages in unvegetated tidal flats of a subtropical estuary. Oil-exposed treatments were contrasted with controls for a duration of four successive days before and after an experimental spill in three distinct areas of the Paranaguá Estuarine Complex (Southern Brazil). No significant differences were observed in nematode total density, number of taxa and the overall assemblage structure between the control and impact treatments from before to after the experimental spill. This reinforces the idea that, despite being good indicators of environmental stress, free-living marine nematodes are able to tolerate low concentrations of hydrocarbons and to survive in moderately contaminated areas. We also show that robust experimental designs are useful to avoid confounding expected natural variability with the effects of a mild impact.
Показать больше [+] Меньше [-]The PAH level, distribution and composition in surface sediments from a Mediterranean Lagoon: The Marano and Grado Lagoon (Northern Adriatic Sea, Italy) Полный текст
2014
Acquavita, Alessandro | Falomo, Jari | Predonzani, Sergio | Tamberlich, Francesco | Bettoso, Nicola | Mattassi, Giorgio
The Marano and Grado Lagoon is one of the best conserved transitional environment in the whole Mediterranean area. On the other hand, it suffers from industrial, agricultural and fisheries activities, which could have an important impact on its environmental quality. With the application of the WFD, the sediment chemical status was investigated. In this work, 16 polycyclic aromatic hydrocarbons included by the US EPA within the priority pollutants were considered. PAHs values ranged from non-detectable to 1056ngg−1 showing the highest contamination close to the Aussa-Corno River mouth, which received the industrial inputs. The contamination level was comparable to that observed in low contaminated sites of the Mediterranean region, and lower than the adjacent Gulf of Trieste. The ratios of selected PAHs congeners pointed out the prevalence of pyrolitic sources. Moreover, the application of the ERL/ERM displayed an environment, which should not have a potential biological impact.
Показать больше [+] Меньше [-]Levels of endocrine disrupting compounds in South China Sea Полный текст
2014
Zhang, Li-Peng | Wang, Xin-Hong | Ya, Miao-Lei | Wu, Yu-Ling | Li, Yong-Yu | Zhang, Zu-lin
The occurrence of estrogens in the aquatic environment has become a major concern worldwide because of their strong endocrine disrupting potency. In this study, concentrations of four estrogenic compounds, estrone (E1), 17β-estradiol (E2), 17α-ethynylestradiol (EE2), estriol (E3) were determined with liquid chromatography-tandem mass spectrometry analyses in surface water from South China Sea, and distributions and potential risks of their estrogenic activity were assessed. The estrogenic compounds E1, E2 and E3 were detected in most of the samples, with their concentrations up to 11.16, 3.71 and 21.63ngL−1. However, EE2 was only detected in 3 samples. Causality analysis, EEQ values from chemical analysis identified E2 as the main responsible compounds. Based on the EEQ values in the surface water, high estrogenic risks were in the coastal water, and low estrogenic risks in the open sea.
Показать больше [+] Меньше [-]Variability of the dissolved nutrient (N, P, Si) concentrations in the Bay of Annaba in relation to the inputs of the Seybouse and Mafragh estuaries Полный текст
2014
Ounissi, Makhlouf | Ziouch, Omar-Ramzi | Aounallah, Ouafia
Dissolved inorganic nitrogen (DIN), phosphate (PO4) and silicic acid (Si(OH)4) loads from the Seybouse and the Mafragh estuaries into the Bay of Annaba, Algeria, were assessed at three stations of the Bay over three years. The Seybouse inputs had high levels of DIN and PO4, in contrast to the Mafragh estuary’s near-pristine inputs; Si(OH)4 levels were low in both estuaries. The DIN:PO4 molar ratios were over 30 in most samples and the Si(OH)4:DIN ratio was less than 0.5 in the Seybouse waters, but nearly balanced in the Mafragh. The specific fluxes of Si–Si(OH)4 (400–540kgSikm−2yr−1) were comparable in the two catchments, but those of DIN were several-fold higher in the Seybouse (373kgNkm−2yr−1). The inner Bay affected by the Seybouse inputs had high levels of all nutrients, while the Mafragh plume and the outer marine station were less enriched.
Показать больше [+] Меньше [-]Vertical profile, sources, and equivalent toxicity of polycyclic aromatic hydrocarbons in sediment cores from the river mouths of Kaohsiung Harbor, Taiwan Полный текст
2014
Dong, Cheng-Di | Chen, Chih-Feng | Chen, Chiu-Wen
Six sediment cores collected at four contaminated river mouths and two harbor entrances in Kaohsiung Harbor (Taiwan) were analyzed to evaluate the sources and potential toxicity of polycyclic aromatic hydrocarbons (PAHs). PAHs presented the wide variations ranging from 369±656 to 33,772±14,378ngg−1 at the six sampling sites. The composition of PAHs presented a uniform profile reflecting the importance of atmospheric input from vehicle exhausts or coal combustion in the river mouths. PAHs diagnostic ratios indicated a stronger influence of coal combustion in the Salt River mouth and the prevalence of petroleum combustion and mixed sources in the other rivers and harbor entrances. PAHs toxicity assessment using the mean effect range-median quotient (m-ERM-q: 0.011–1.804), benzo[a]pyrene-toxicity equivalent (TEQcarc: 22–2819ngTEQg−1), and dioxin-toxicity equivalent (TEQfish: 37–5129pgTEQg−1) identified the Salt River mouth near the industrial area of the harbor as the most affected area.
Показать больше [+] Меньше [-]Baseline concentrations of faecal sterols and assessment of sewage input into different inlets of Admiralty Bay, King George Island, Antarctica Полный текст
2014
Martins, César C. | Aguiar, Sabrina N. | Wisnieski, Edna | Ceschim, Liziane M.M. | Figueira, Rubens C.L. | Montone, Rosalinda C.
The Antarctic region is one of the best preserved environments in the world. However, human activities such as the input of sewage result in the alteration of this pristine site. We report baseline values of faecal sterols in Admiralty Bay, Antarctica. Four sediment cores were collected during the 2006/2007 austral summer at the Ezcurra (THP and BAR), Mackelar (REF) and Martel (BTP) inlets. Concentrations of faecal sterols (coprostanol+epicoprostanol) were <0.16μgg−1, suggesting no sewage contamination and probable “biogenic” contributions for these compounds. Baseline values, calculated using the mean concentration of faecal sterols in core layers for THP, BAR, REF and BTP, were 0.04±0.02, 0.03±0.01, 0.07±0.01 and 0.04±0.02μgg−1, respectively. These results established as natural contributions of faecal sterols, suggesting that these markers can be useful indicators of human-derived faecal input and contributing to monitoring programs to prevent anthropogenic impacts.
Показать больше [+] Меньше [-]Organochlorine pesticide content and distribution in coastal seafoods in Zhoushan, Zhejiang Province Полный текст
2014
Wang, Jie-yu | Yu, Xin-wei | Fang, Li
Thirteen types of seafoods were collected from four counties (districts) of Zhoushan, Zhejiang Province, China and analyzed for organochlorine pesticides (OCPs). The average concentrations of OCPs in seafoods ranged from 258.3ngg−1 (lw) to 3459.6ngg−1 (lw). Hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) were the most abundant compounds in these environments and in total accounted for 8.2–62.2% and 32.1–89.0% of the total OCPs in seafoods, respectively. The total OCP contents were higher in seafoods from Shengsi and Putuo and lower in those from Dinghai and Daishan. The ratios of (DDE+DDD)/DDTs reflected a mixed input of accumulated and fresh DDTs in Shengsi, Putuo. The ratios of o,p′-DDT/p,p′-DDT in seafoods of Shengsi ranged 0.10–0.60 (mean 0.33), indicating that DDTs in seafoods of Shengsi may partly contain dicofol products and other pollutants accumulated in Yangtze Estuary. DDTs are a greater concern for ecotoxicological risk in the study area.
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