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Total petroleum hydrocarbons and heavy metals in the surface sediments of Bohai Bay, China: Long-term variations in pollution status and adverse biological risk Texte intégral
2014
Zhou, Ran | Qin, Xuebo | Peng, Shitao | Deng, Shihuai
Surface sediments collected from 2001 to 2011 were analyzed for total petroleum hydrocarbons (TPH) and five heavy metals. The sediment concentration ranges of TPH, Zn, Cu, Pb, Cd and Hg were 6.3–535μg/g, 58–332μg/g, 7.2–63μg/g, 4.3–138μg/g, 0–0.98μg/g, and 0.10–0.68μg/g, respectively. These results met the highest marine sediment quality standards in China, indicating that the sediment was fairly clean. However, based on the effects range-median (ERM) quotient method, the calculated values for all of the sampling sites were higher than 0.10, suggesting that there was a potential adverse biological risk in Bohai Bay. According to the calculated results, the biological risk decreased from 2001 to 2007 and increased afterwards. High-risk sites were mainly distributed along the coast. This study suggests that anthropogenic influences might be responsible for the potential risk of adverse biological effects from TPH and heavy metals in Bohai Bay.
Afficher plus [+] Moins [-]Ghost fishing activity in derelict blue crab traps in Louisiana Texte intégral
2014
Derelict crab traps impact the coastal ecosystem through continued catch of target species and species of conservation, economic, or recreational importance. During volunteer-supported crab trap cleanups in 2012 and 2013, we quantified ghost fishing activity in derelict crab traps in coastal Louisiana through a citizen scientist program. Volunteers removed 3607 derelict traps during these events, and over 65% of traps analyzed by citizen scientists were actively ghost fishing. Additionally, volunteers identified 19 species enmeshed in derelict traps, including a combination of fresh and saltwater species. We also detected a significant difference in the number of blue crab in actively ghost fishing derelict traps across removal locations with estimated catches varying between 2.4 and 3.5 crabs/trap. Our instantaneous estimates of ghost fishing activity are greater than those previously thought in Louisiana, further justifying current derelict crab trap prevention and removal extension and outreach programs in Louisiana and throughout the Gulf of Mexico.
Afficher plus [+] Moins [-]Modeling total maximum allocated loads for heavy metals in Jinzhou Bay, China Texte intégral
2014
Li, Keqiang | Shi, Xiaoyong | Bao, Xianwen | Ma, Qimin | Wang, Xiulin
With the recent development of society and economy in the cities of Huludao and Jinzhou, Liaoning Province, China, environment and ecosystem problems have become increasingly serious in Jinzhou Bay, China, because of the increasing amount of heavy metal pollutants being discharged. To solve these problems, a water quality model of heavy metals coupled with a 3D hydrodynamic model is constructed to estimate the environmental capacity (EC) and total maximum allocated loads (TMALs) for Zn and Cd of three river catchments in Jinzhou Bay. According to the model, the ECs for Zn and Cd are approximately 17 and 8tons per month, respectively, if the criterion obtained from HC5 values (fifth percentile of the SSD) is set as the control criterion (8.24μg/L for Zn and 3.83μg/L for Cd) in Jinzhou Bay, and the TMALs of the three river catchments are 4 and 1.7 tons per month.
Afficher plus [+] Moins [-]Comparison of metal accumulation in the azooxanthellate scleractinian coral (Tubastraea coccinea) from different polluted environments Texte intégral
2014
Chan, Isani | Hung, Jia-Jang | Peng, Shao-Hung | Tseng, Li-Chun | Ho, Tung-Yuan | Hwang, Jiang-Shiou
The response of metal accumulation in coral Tubastraea coccinea to various degrees of metal enrichment was investigated from the Yin-Yang Sea (YYS) receiving abandoned mining effluents, the Kueishan Islet (KI) hydrothermal vent field, and the nearshore area of remoted Green Island (GI). The concentrations of most dissolved metals were highest in seawater at YYS, followed by KI, and then GI, showing the effects of anthropogenic and venting inputs on metal levels. Five metals (Co, Fe, Mn, Ni, and Zn) yielded significant differences (p<0.05) among the skeleton samples. We identified similar patterns in the metal–Ca ratios, indicating that the elevated metals in skeletons was a consequence of external inputs. The coral tissues were relatively sensitive in monitoring metal accumulation, showing significant differences among three locations for Cd, Co, Cu, Fe, Pb, Ni, and Zn. Specific bioconcentration factors provided strong support for the differential metal accumulation in skeletons and tissues.
Afficher plus [+] Moins [-]Monitoring plant response to phenanthrene using the red edge of canopy hyperspectral reflectance Texte intégral
2014
Zhu, Linhai | Chen, Zhongxin | Wang, Jianjian | Ding, Jinzhi | Yu, Yunjiang | Li, Junsheng | Xiao, Nengwen | Jiang, Lianhe | Zheng, Yuanrun | Rimmington, Glyn M.
To investigate the mechanisms and potential for the remote sensing of phenanthrene-induced vegetation stress, we measured field canopy spectra, and associated plant and soil parameters in the field controlled experiment in the Yellow River Delta of China. Two widely distributed plant communities, separately dominated by reed (Phragmites australis) and glaucous seepweed (Suaeda salsa), were treated with different doses of phenanthrene. The canopy spectral changes of plant community resulted from the decreases of biomass and foliar projective coverage, while leaf photosynthetic pigment concentrations showed no significance difference among treatments. The spectral response to phenanthrene included a flattened red edge, with decreased first derivative of reflectance. The red edge slope and area consistently responded to phenanthrene, showing a strong relationship with aboveground biomass, coverage and canopy pigments density. These results suggest the potential of remote sensing and the importance of field validation to correctly interpret the causes of the spectral changes.
Afficher plus [+] Moins [-]Distribution and transfer pattern of Polychlorinated Biphenyls (PCBs) among the selected environmental media of Ny-Ålesund, the Arctic: As a case study Texte intégral
2014
Zhang, Peng | Ge, Linke | Gao, Hui | Yao, Ting | Fang, Xiaodan | Zhou, Chuanguang | Na, Guangshui
Polychlorinated Biphenyls (PCBs) were analyzed in multi-environmental samples collected from Ny-Ålesund, the Arctic to explore their legacy and transfer patterns. PCBs were ubiquitously in the environmental media, within the ranges of 1.73–6.27 and 9.18–141.1pgm−3 in vapor and aerosol, 2.76–10.8, 3.09–8.32, 22.5–56.3, 35.4–51.4 and 31.8–39.6ngg−1 (dry weight) in soil, sediment, plant, bird guano and reindeer faeces, respectively. The spatial distribution patterns exhibited a general southward decline in soil and sediment from the bay entrance to the inner bay. The concentration ratios of plants to soil inferred that no distinguished selective adsorption of PCBs congeners by plants existed and PCBs were mainly attributed to the air deposition on plant surface. The fugacity ratios among vapor, aerosol and soil indicted that the equilibrium status has not been reached and the net transferring direction was air–soil.
Afficher plus [+] Moins [-]Macrobenthic diversity in protected, disturbed, and newly formed intertidal wetlands of a subtropical estuary in China Texte intégral
2014
Lv, Weiwei | Ma, Chang-an | Huang, Youhui | Yang, Yang | Yu, Ji | Zhang, Mingqing | Zhao, Yunlong
In this study, intertidal macrobenthic diversity in protected, disturbed, and newly formed wetlands of Yangtze estuary was assessed using PRIMER 5.2 based on species diversity and species relatedness. We observed high diversity in nature reserves and low diversity in adjacent disturbed and newly formed wetlands. These diversity data were then integrated with historical data to detect the variation in macrobenthic diversity over the past two decades. The integrated data indicated that the intertidal macrobenthic diversity sharply decreased in heavy reclamation tidal flats whereas markedly increased in non-disturbed nature reserve and newly formed wetland. Benthic health was observed with the departure degree of average taxonomic distinctness (Δ+) and variation in taxonomic distinctness (Λ+) from the simulated 95% confidence funnel. All the habitats were subjected to different levels of human interference, except Jiuduansha and Beigangbeisha. The degradation of intertidal wetland in Yangtze estuary was mainly attributed to land reclamation, overgrazing, and overfishing.
Afficher plus [+] Moins [-]Review of oil spill remote sensing Texte intégral
2014
Fingas, Mervin F. | Brown, Carl
Remote-sensing for oil spills is reviewed. The use of visible techniques is ubiquitous, however it gives only the same results as visual monitoring. Oil has no particular spectral features that would allow for identification among the many possible background interferences. Cameras are only useful to provide documentation. In daytime oil absorbs light and remits this as thermal energy at temperatures 3–8K above ambient, this is detectable by infrared (IR) cameras.Laser fluorosensors are useful instruments because of their unique capability to identify oil on backgrounds that include water, soil, weeds, ice and snow. They are the only sensor that can positively discriminate oil on most backgrounds. Radar detects oil on water by the fact that oil will dampen water-surface capillary waves under low to moderate wave/wind conditions. Radar offers the only potential for large area searches, day/night and foul weather remote sensing.
Afficher plus [+] Moins [-]Geochemical characteristics of phosphorus in surface sediments of two major Chinese mariculture areas: The Laizhou Bay and the coastal waters of the Zhangzi Island Texte intégral
2014
Zhuang, Wen | Gao, Xuelu | Zhang, Yong | Xing, Qianguo | Tosi, Luigi | Qin, Song
Phosphorus (P) in surface sediments of the Laizhou Bay (LB) and the coastal waters around the Zhangzi Island (ZI) was analyzed. Six forms of P were separated — exchangeable or loosely sorbed P (Ads–P), aluminum-bound P (Al–P), iron-bound P (Fe–P), authigenic apatite plus CaCO3-bound P plus biogenic apatite (Ca–P), detrital apatite plus other inorganic P (De–P) and organic P (OP). The average contents of P in the LB were in the order: De–P>OP>Ca–P>Fe–P>Ads–P>Al–P; in the ZI, the corresponding order was De–P>OP>Fe–P>Ca–P>Ads–P>Al–P. Due to the high nutrient loadings from the surrounding rivers, TP contents in sediments of the LB were higher than in those of the ZI. The potential bio-available P (Ads–P and OP) accounted for 14.7% and 24.2% of TP in sediments of the LB and the ZI, respectively.
Afficher plus [+] Moins [-]Impacts of Macondo oil from Deepwater Horizon spill on the growth response of the common reed Phragmites australis: A mesocosm study Texte intégral
2014
Judy, Chad R. | Graham, Sean A. | Lin, Qianxin | Hou, Aixin | Mendelssohn, I. A.
We investigated impacts of Macondo MC252 oil from the Deepwater Horizon (DWH) spill on the common reed Phragmites australis (Cav.) Trin. ex Steud., a dominant species of the Mississippi River Delta. In greenhouse experiments, we simulated the most common DWH oiling scenarios by applying weathered and emulsified Macondo oil to aboveground shoots at varying degrees of coverage (0–100%) or directly to marsh soil at different dosages (0–16Lm−2). P. australis exhibited strong resistance to negative impacts when oil was applied to shoots alone, while reductions in above- and belowground plant growth were apparent when oil was applied to the soil or with repeated shoot-oiling. Although soil-oiling compromised plant function, mortality of P. australis did not occur. Our results demonstrate that P. australis has a high tolerance to weathered and emulsified Macondo oil, and that mode of exposure (aboveground versus belowground) was a primary determinant of impact severity.
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