Sources and factors influencing the spatial distribution of heavy metals in a coastal lagoon adjacent to the San Quintín volcanic field, Baja California, Mexico     

Gutiérrez-Galindo EA  Muñoz-Barbosa A  Daesslé LW  Macías-Zamora JV  Segovia-Zavala JA 《Marine pollution bulletin》2007,54(12):1985-1989

  相似文献   

Influence of salinity and fish species on PAH uptake from dispersed crude oil     

Ramachandran SD  Sweezey MJ  Hodson PV  Boudreau M  Courtenay SC  Lee K  King T  Dixon JA 《Marine pollution bulletin》2006,52(10):1182-1189

The use of chemical oil dispersants to minimize spill impacts causes a transient increase in hydrocarbon concentrations in water, which increases the risk to aquatic species if toxic components become more bioavailable. The risk of effects depends on the extent to which dispersants enhance the exposure to toxic components, such as polycyclic aromatic hydrocarbons (PAH). Increased salinities can reduce the solubility of PAH and the efficiency of oil dispersants. This study measured changes in the induction of CYP1A enzymes of fish to demonstrate the effect of salinity on PAH availability. Freshwater rainbow trout and euryhaline mummichog were exposed to water accommodated fractions (WAF), and chemically-enhanced water accommodated fractions (CEWAF) at 0 per thousand, 15 per thousand, and 30 per thousand salinity. For both species, PAH exposure decreased as salinity increased whereas dispersant effectiveness decreased only at the highest salinity. Hence, risks to fish of PAH from dispersed oil will be greatest in coastal waters where salinities are low.  相似文献   

Short-term effects of the prestige oil spill on the peregrine falcon (Falco peregrinus)     

Zuberogoitia I  Martínez JA  Iraeta A  Azkona A  Zabala J  Jiménez B  Merino R  Gómez G 《Marine pollution bulletin》2006,52(10):1176-1181

We have monitored the distribution, population status, breeding success, turnover rate and diet of a Peregrine Falcon population in Bizkaia (North of Spain) since 1997. On the 13th November 2002, the tanker Prestige sunk off La Coruña (NW Spain) causing an oil spill that affected the whole of the Cantabrian Coast and the Southwest of France. The total number of birds affected by the Prestige oil spill was expected to be between 115,000 and 230,000, some of them raptors. The loss of clutches during the incubation period increased significantly and was correlated with the loss of females. Moreover, the turnover rate of the population increased from 21% to 30%. The polycyclic aromatic hydrocarbon concentrations in the eggs, collected from five nests after they were deserted, ranged from 21.20 ng/g to 461.08 ng/g, values which are high enough to cause the death of the embryos and poisoning of adult birds. The effects of pollution reached inland since some inland-breeding falcons prey on shorebirds that use rivers during their migratory flights. As the Prestige oil spill has clearly resulted in increased rates of adult mortality and reduced fertility, we suggest that the environmental authorities urgently undertake measures aimed at protecting the Peregrine Falcon in Bizkaia.  相似文献   

冷泉区底栖有孔虫研究进展   总被引：1，自引：0，他引：1  

向荣  刘芳  陈忠  颜文  陈木宏 《地球科学进展》2010,25(2):193-202

海底冷泉区是海洋能源和生物资源同时富集的一类特殊区域。底栖有孔虫群落及其地球化学组成是海底冷泉区发育的重要指示标志之一。海底冷泉区的底栖有孔虫及其碳同位素研究,对于探讨冷泉演化、评估古冷泉甲烷排放对全球气候变化的影响有重要的研究意义。综述了全球一些主要冷泉区的底栖有孔虫研究方法及其进展,对比了各冷泉区底栖有孔虫群落结构的主要特征及地域差异,评述了冷泉区底栖有孔虫的碳同位素记录特征、影响因素及其对冷泉活动的潜在指示意义,最后提出了南海北部冷泉活动区底栖有孔虫方面的研究展望。  相似文献   

掺Zn球形氢氧化镍的研究     

黄朝辉  罗方承  陈忠锡  吴江  罗六保 《矿产与地质》2001,15(Z1):552-555

采用化学沉淀法制备球形氢氧化镍,通过对制备条件pH值、添加剂量、搅拌强度的研究,探讨了其对掺Zn球形氢氧化镍  相似文献   

TRACE and Yohkoh Observations of High-Temperature Plasma in a Two-Ribbon Limb Flare     

Warren HP  Bookbinder JA  Forbes TG  Golub L  Hudson HS  Reeves K  Warshall A 《The Astrophysical journal》1999,527(2):L121-L124

The ability of the Transition Region and Coronal Explorer (TRACE) to image solar plasma over a wide range of temperatures (Te approximately 104-107 K) at high spatial resolution (0&farcs;5 pixels) makes it a unique instrument for observing solar flares. We present TRACE and Yohkoh observations of an M2.4 two-ribbon flare that began on 1999 July 25 at about 13:08 UT. We observe impulsive footpoint brightenings that are followed by the formation of high-temperature plasma (Te greater, similar10 MK) in the corona. After an interval of about 1300 s, cooler loops (Te<2 MK) form below the hot plasma. Thus, the evolution of the event supports the qualitative aspects of the standard reconnection model of solar flares. The TRACE and Yohkoh data show that the bulk of the flare emission is at or below 10 MK. The TRACE data are also consistent with the Yohkoh observations of hotter plasma (Te approximately 15-20 MK) existing at the top of the arcade. The cooling time inferred from these observations is consistent with a hybrid cooling time based on thermal conduction and radiative cooling.  相似文献   

难回收硫化物金矿的生物氧化预处理     

Brie.  JA 赵珉 《云南地质科技情报》1993,(2):74-82

  相似文献   

Esterase activities in the bivalve mollusc Adamussium colbecki as a biomarker for pollution monitoring in the Antarctic marine environment     

Bonacci S  Browne MA  Dissanayake A  Hagger JA  Corsi I  Focardi S  Galloway TS 《Marine pollution bulletin》2004,49(5-6):445-455

Marine environments are continuously being threatened by a large number of xenobiotics from anthropogenic sources. Even in sparsely populated and relatively pristine areas, such as Antarctica, hazardous chemicals can pose a serious environmental problem. The main aims of the present study were to (1) validate and optimize an analytical technique utilizing a microtitre-plate photometer to ascertain background levels of esterase activities in the Antarctic bivalve Adamussium colbecki, (2) carry out in situ monitoring of esterase activities to assess any potential environmental impacts of the Italian Scientific Antarctic Base "Terra Nova Bay" on the surrounding marine area. Results showed the presence of organophosphorous-sensitive cholinesterase (ChE) and carboxylesterase (CbE) activities in the gills of A. colbecki and optimal assay conditions were comparable with those found for bivalve species from temperate areas. A higher sensitivity of ChE versus acetylthiocholine activity in A. colbecki to chlorpyrifos compared to species from temperate areas may also be inferred. The in situ study indicated no differences in the environmental quality of the three study sites located around the Italian Base.  相似文献   

Hydraulics of recirculating well pairs for ground water remediation   总被引：1，自引：0，他引：1  

Cunningham JA  Hoelen TP  Hopkins GD  Lebrón CA  Reinhard M 《Ground water》2004,42(6-7):880-889

Recirculating well pairs are a proven means of implementing bioremediation and may also be useful for applying other in situ ground water remediation technologies. A bromide tracer test was performed to characterize the hydraulic performance of a recirculating well pair installed at Moffett Field, California. In particular, we estimate two important properties of the recirculating well pair: (1) the fraction of captured water that is recycled between the wells, and (2) the travel-time distribution of ground water in the induced zone of recirculation. We also develop theoretical estimates of these two properties and demonstrate they depend upon a dimensionless pumping rate, denoted xi. The bromide breakthrough curve predicted from theory agrees well with that determined experimentally at Moffett Field. The minimum travel time between the wells is denoted t(min). In theory, t(min) depends inversely on Q, the pumping rate in the recirculating wells, and is proportional to a2, the square of the distance between the wells. Both the experimental and theoretical travel-time distributions indicate that at least half the recirculating water travels between the wells along fast flowpaths (travel time < 2*t(min)). Therefore, when designing recirculating well pairs, engineers should ensure that t(min) will be sufficiently high to allow biologically mediated reactions (or other in situ remediation processes) sufficient time to proceed.  相似文献   

Organochlorine contaminants in sea turtles from the Eastern Pacific     

Gardner SC  Pier MD  Wesselman R  Juárez JA 《Marine pollution bulletin》2003,46(9):1082-1089

We measured organochlorine residues in three species of sea turtles from the Baja California peninsula, Mexico. Seventeen of 21 organochlorine pesticides analyzed were detected, with heptachlor epoxide and gamma-hexachlorocyclohexane the most prevalent (14 (40%) and 11 (31%) of the 35 tissue samples, respectively). PCBs were detected in all but one of the 9 turtles studied, with congener 18 the most commonly detected (8 (23%) of the samples). The dioxin-like congeners 118 and 180 were detected in 4 (11%) and 3 (9%) of the samples, respectively. Percent contribution of congeners was negatively correlated to their octanol-water partition coefficients, with kidney and muscle containing more lower-chlorinated congeners than liver or adipose samples. Levels of organochlorines detected in the present study were low, potentially attributable to the feeding habits of the predominant species collected in this study (herbivorous) and/or the samples obtained in an unindustrialized region.  相似文献