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Environmental capacity of nitrogen and phosphorus pollutions in Jiaozhou Bay, China: Modeling and assessing 全文
2011
Han, Hongyan | Li, Keqiang | Wang, Xiulin | Shi, Xiaoyong | Qiao, Xudong | Liu, Jing
In recent years, with the development of society and economy of Qingdao, environment and ecosystem problems, for instance, red ties, become more and more serious in Jiaozhou Bay, China, because of the increasing pollutants discharged into it. In order to solve these problems, an eco-hydrodynamic model is constructed to estimate the marine environmental capacity of nitrogen and phosphorus nutrients in Jiaozhou Bay, whose simulation results are rational for the bay. According to the model, if the target is set to achieve water quality (grade II) in Jiaozhou Bay, the environmental capacity of dissolved inorganic nitrogen and phosphorus in one year are approximately 7800 and 840tons, respectively. Thus our research offers necessary scientific foundation to the total loads control efforts in this area.
显示更多 [+] 显示较少 [-]The marine medaka Oryzias melastigma – A potential marine fish model for innate immune study 全文
2011
Bo, Jun | Cai, Ling | Xu, Jia-He | Wang, Ke-Jian | Au, Doris W.T.
The objective of this study is to develop the marine medaka Oryzias melastigma as a potential marine fish model for innate immune and immunotoxicological studies. Hepcidin plays an important role in innate immune system. Two hepcidin genes (OM-hep1 and OM-hep2) were identified and characterized in the O. melastigma, which were highly conserved with other reported hepcidins. During embryogenesis, significant elevation of OM-hep1 and OM-hep2 transcripts were coincided with liver development in the embryos. In adult medaka, differential tissue expressions of both hepcidin transcripts were evident: high in liver, moderate in spleen and low in non-immune tissues. After bacterial challenge, the two hepcidin mRNAs were rapidly and remarkably induced in liver and spleen, suggesting the two OM-hepcidins in O. melastigma play a complementary role in innate defense. Gender difference in time of induction and extent of the two hepcidin mRNAs elevation in infected O. melastigma should be considered in immunotoxicological studies.
显示更多 [+] 显示较少 [-]Differences in leaf construction cost between alien and native mangrove species in Futian, Shenzhen, China: Implications for invasiveness of alien species 全文
2011
Li, Fenglan | Yang, Qiong | Zan, Qijie | Tam, Nora F.Y. | Shin, Paul K.S. | Vrijmoed, Lilian L.P. | Cheung, S.G.
Construction cost (CC) is a quantifiable measure of energy demand for biomass production, and low CC is hypothesized to give an alien plant growth advantages and increase its potential to be an invader. Comparison of leaf CC and growth traits between alien and native mangroves in Shenzhen Futian Nature Reserve showed CC per unit mass (CCₘₐₛₛ), carbon concentration and gross and ash-free caloric values of alien mangroves were significantly lower than those of native species, while the height and chest circumference were just the opposite. Alien species Sonneratia apetala had the lowest CCₘₐₛₛ while Sonneratia caseolaris had the lowest CCₐᵣₑₐ, and were 8.99% and 32.17% lower than those of native species, respectively. Conversely, specific leaf area (SLA) of these two Sonneratia species was significantly higher than native species. Lower CC and higher SLA make the two Sonneratia species grow and spread faster than other mangroves and enhance their invasive potential.
显示更多 [+] 显示较少 [-]Isolation, characterization of Rhodococcus sp. P14 capable of degrading high-molecular-weight polycyclic aromatic hydrocarbons and aliphatic hydrocarbons 全文
2011
Song, Xiaohui | Xu, Yan | Li, Gangmin | Zhang, Ying | Huang, Tongwang | Hu, Zhong
Rhodococcus sp. P14 was isolated from crude oil-contaminated sediments. This strain was capable of utilizing three to five rings polycyclic aromatic hydrocarbons (PAHs) including phenanthrene (Phe), pyrene (Pyr), and benzo[a]pyrene (BaP) as a sole carbon and energy source. After cultivated with 50mg/L of each PAH, strain P14 removed 43% Phe, 34% Pyr and 30% BaP in 30 d. Four different hydroxyphenanthrene products derived from Phe by strain P14 (1,2,3,4-hydroxyphenanthrene) were detected using SPME–GC–MS. Strain P14 also was capable of degrading mineral oil with n-alkanes of C17 to C21 carbon chain length. Compared with glucose-grown cells, PAHs-grown cells had decreased contents of shorter-chain length fatty acids (⩽C16:0), increased contents of C18:0, Me-C19:0 and disappeared odd-number carbon chain fatty acids. The contents of unsaturated C19:1, Me-C19:0 increased and C18:0 decreased in mineral oil-grown cells. At the same time, the strain P14 tended to float when cultivated in mineral oil-supplemented liquid medium. The degradation capability of P14 to alkane and PAHs and its floating characteristics will be very helpful for future’s application in oil-spill bioremediation.
显示更多 [+] 显示较少 [-]Plant growth and the performance of mangrove wetland microcosms for mariculture effluent depuration 全文
2011
Su, Yung-Ming | Lin, Yingfeng | Jing, Shuh-Ren | Lucy Hou, Ping-Chun
This study established wetland microcosms that were either unplanted or planted in monoculture with native mangrove species in Taiwan (Avicennia marina, Rhizophora stylosa, and Lumnitzera racemosa) for the purpose of receiving high-salinity mariculture effluents; additionally, the microcosms operated at different hydraulic retention times (HRTs). Plant growth and the performance of the microcosms with respect to pollutant removal were investigated. The results showed that seedlings of all three mangrove species survived and grew sufficiently well under continuous flooding. The presence of mangroves consistently improved SS, BOD₅, and TP removal, particularly under short HRT conditions. The mangrove microcosms removed pollutants from the mariculture effluents with efficiencies of 5.7–27.1% (SS), 4.9–36.3% (BOD₅), 18.7–29.9% (TP), 21.2–49.8% (NH₄-N), and 5.4–37.7% (NOₓ-N). A. marina and L. racemosa were more tolerant of continuous flooding than R. stylosa. However, no species displayed consistently superior performance in decreasing all pollutant-related parameters investigated. For all pollutants, microcosms operating at a 2-d HRT exhibited a higher removal efficiency than those operating at a 0.5-d HRT.
显示更多 [+] 显示较少 [-]Analysis of bacterial diversity and metals in produced water, seawater and sediments from an offshore oil and gas production platform 全文
2011
Yeung, C William | Law, Brent A. | Milligan, Tim G. | Lee, Kenneth | Whyte, Lyle G. | Greer, Charles W.
Produced water is one of the largest waste products routinely discharged into the ocean from offshore oil and gas platforms. This study analyzed bacterial communities and metals in the produced water, surrounding seawater, and sediment around the Thebaud platform. The bacterial community within the produced water was different from the seawater (SAB=13.3), but the discharge had no detectable effect on the bacterial communities in the seawater (SAB>97). In contrast, genomic analysis of sediments revealed that the bacterial community from 250m was different (SAB=70) from other locations further from the discharge, suggesting that the produced water had a detectable effect on the bacterial community in the sediment closest to the discharge. These near-field sediments contained elevated concentrations of manganese and iron that are associated with the produced water effluent. The results suggested that the discharge of produced water has influenced the bacterial community structure of sediments adjacent to the platform.
显示更多 [+] 显示较少 [-]Plastic contamination in the decapod crustacean Nephrops norvegicus (Linnaeus, 1758) 全文
2011
Murray, Fiona | Cowie, Phillip Rhys
The aim of this study was to determine the extent Nephrops consumes plastics in the Clyde Sea and if this intake occurs through their diet. Plastic contamination was found to be high in Nephrops, 83% of the animals sampled contained plastics (predominately filaments) in their stomachs. Tightly tangled balls of plastic strands were found in 62% of the animals studied but were least prevalent in animals which had recently moulted. No significant difference in plastic load was observed between males and females. Raman spectroscopy indicated that some of the microfilaments identified from gut contents could be sourced to fishing waste. Nephrops fed fish seeded with strands of polypropylene rope were found to ingest but not to excrete the strands. The fishery for Norway lobster, Nephrops norvegicus, is the most valuable in Scotland and the high prevalence of plastics in Nephrops may have implications for the health of the stock.
显示更多 [+] 显示较少 [-]The toxicity and oxidative stress of TiO₂ nanoparticles in marine abalone (Haliotis diversicolor supertexta) 全文
2011
Zhu, Xiaoshan | Zhou, Jin | Cai, Zhonghua
The increasing use of nanotechnology highlights the need to understand and clarify the environmental impacts of nanomaterials. In this study, the acute toxicity and oxidative stress of titanium dioxide nanoparticles (nTiO₂) in mature marine abalone (Haliotis diversicolor supertexta) were assessed. No acute effect was found in any of the treatment groups with nTiO₂ concentration gradients ranging from 0.1 to 10mg/L. However, the activity of an antioxidant enzyme superoxide dismutase (SOD) significantly increased in the group that was exposed to 1.0mg/L nTiO₂. The content of a non-enzymatic antioxidant, glutathione (GSH), significantly decreased in the groups with an nTiO₂ concentration ⩾1.0mg/L. The level of lipid peroxidation (LPO) was found to increase as the nTiO₂ dose increased. Furthermore, NO was produced in excess in abalone. These results demonstrated that, although nTiO₂ is not acutely toxic to abalone, it does exert oxidative stress on abalone.
显示更多 [+] 显示较少 [-]Establishment of numerical beach-litter hindcast/forecast models: An application to Goto Islands, Japan 全文
2011
Kako, Shin’ichiro | Isobe, Atsuhiko | Magome, Shinya | Hinata, Hirofumi | Seino, Satoquo | Kojima, Azusa
This study attempts to establish a system for hindcasting/forecasting the quantity of litter reaching a beach using an ocean circulation model, a two-way particle tracking model (PTM) to find litter sources, and an inverse method to compute litter outflows at each source. Twelve actual beach survey results, and satellite and forecasted wind data were also used. The quantity of beach litter was hindcasted/forecasted using a forward in-time PTM with the surface currents computed in the ocean circulation model driven by satellite-derived/forecasted wind data. Outflows obtained using the inverse method was given for each source in the model. The time series of the hindcasted/forecasted quantity of beach litter were found consistent with the quantity of beach litter determined from sequential webcam images of the actual beach. The accuracy of the model, however, is reduced drastically by intense winds such as typhoons which disturb drifting litter motion.
显示更多 [+] 显示较少 [-]Arsenic and trace metal contents in sediment profiles from the Admiralty Bay, King George Island, Antarctica 全文
2011
Ribeiro, Andreza P. | Figueira, Rubens C.L. | Martins, César C. | Silva, Charles R.A. | França, Elvis J. | Bícego, Márcia C. | Mahiques, Michel M. | Montone, Rosalinda C.
Admiralty Bay (Antarctica) hosts three scientific stations (Ferraz, Arctowski and Macchu Picchu), which require the use of fossil fuel as an energy source. Fossil fuels are also considered the main source of pollution in the area, representing important inputs of major pollutants (organic compounds) and trace metals and metalloids of environmental interest. Accordingly, this work presents the results of As, Cd, Cr, Cu, Ni, Pb and Zn in sediment profiles from Admiralty Bay. The sediment results from Ferraz station were slightly higher than the other sampling sites. The highest contents were observed for Cu and Zn (from 44 to 89mgkg⁻¹). Otherwise, by using enrichment factors and geochronology analysis, the most relevant enrichment was observed for As in the samples collected close to the Ferraz station, indicating that increasing As content may be associated with the activities associated with this site.
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