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31.
Water and particles from three sites located in Halifax Harbour, near and further away from combined municipal sewage effluents (CMSE) were analysed for parental and alkylated polycyclic aromatic hydrocarbons (par and alkPAH). Bioavailability of PAH was compared for inter-tidal mussels collected at the same sites in April and November. The PAH fingerprint determined over 9 sampling times covering a period of 19 months differed more between phases (water and particles) and seasons, than between sites. In the spring, more alkPAH associated with diesel and gasoline were detected in the soluble phase, along with more bioaccumulation of alkPAH in inter-tidal mussels. A broader number of parPAH were detected in mussels collected in the fall. The mean sum of dissolved alkPAH concentrations was higher in water at the site closer to raw CMSE than at the other two sites and particles of that site. However, lowest bioconcentration factors (BCF) were determined in mussels of this more contaminated site. Similar biota-particle accumulation factors (BPAF) were determined for parPAH in mussels from the three sites, all lower than the BCF of alkPAH. The study indicates that sewage treatment plants will reduce the amount of parPAH especially larger than fluoranthene and pyrene from being deposited in the harbour; that alk naphthalenes and fluorenes present in water will continue to be discharged; that the disturbance of sediments can make particle-bound PAH available to mussels.  相似文献   
32.
日本海南部地区的地质构造可根据海底地形特征及地震反射剖面而了解,因为地形特征和地层的上超和顶超界限被认为与该区的构造运动密切相关。  相似文献   
33.
Hydrophobic contaminants, such as polycyclic aromatic hydrocarbons (PAHs) readily adsorb to organic matter. The aim of this study was to determine the importance of the quality of sedimentary organic matter for the uptake, biotransformation and toxicity of the PAH, fluoranthene (Flu), in the infaunal brittle star Amphiura filiformis. Brittle stars were exposed to a base sediment covered by a 2 cm Flu-spiked top layer (30 microg Flu/g dry wt. sed.), enriched to the same total organic carbon content with either refractory or labile organic matter. The labile carbon source was concentrated green flagellate: Tetraselmis spp. The refractory carbon source was lignin from a paper mill. Tissue concentrations of Flu both in disk and arm-fractions were determined as total Flu, parent Flu (i.e. untransformed), aqueous Flu-metabolites, polar Flu-metabolites and tissue residue Flu (i.e. unextractable). Our results showed that sediment particle ingestion is a pathway by which Flu can enter benthic food webs. Flu toxicity (measured as arm-regeneration), but not net accumulation, was dependent on the nutritional quality of the ingested sediment particles. Flu bioaccumulation could not be attributed solely to equilibrium partitioning between organism lipid content and organic content of the sediment. Biotransformation of Flu by brittle stars was very limited and unaffected by organic matter quality. A. filiformis contributed to the downward transport of Flu from the surface sediment to the burrow lining. The limited breakdown of parent Flu by brittle stars and/or microorganisms was relatively higher in burrows compared to surface sediment, and highest in the presence of labile organic matter. Tissue concentrations were higher in disk than in arms, but the proportion of metabolic products relative to parent Flu was higher in arms than in the disk fraction. We estimate that the yearly mobilization of sediment-associated Flu by arm-regeneration in A. filiformis is in the range of 3.8-29.4 microg total Flu eq. m(-2) year(-1) at a sediment concentration of 30 microg Flu/g dry wt. sed.  相似文献   
34.
1984年海洋学工程的主要措施是在空间建立海洋观察站。新的海军遥控海洋测向系统卫星(NROSS)和欧洲空间站的地球资源卫星(ERS—Ⅰ)已得到政府的批准,列入了预算项目,开展了利用卫星调查内容的计划和操作运行的计划。NROSS 的传感器有用于风的 NASA(国家航空和航天局)的传播计量器;用于水面温度,冰的性质和海冰边端的微波无线  相似文献   
35.
Since 1998, a biomonitoring programme has been implemented to assess the potential impact of chemical mosquito control on macroinvertebrates of the coastal wetlands of Morbihan (Brittany, France). Acetylcholinesterase and carboxylesterases were used as biomarkers to assess the effects of Abate 500e (a.i. temephos) and Vectobac 12 AS (a.i. endotoxins of Bacillus thuringiensis var. israelensis, Bti) in Nereis (Hediste) diversicolor. Esterase inhibition revealed a marked impact of temephos, suggesting preferential contamination of the worms through the food. In Bti-exposed N. diversicolor, random variations of esterase activities were observed, that could not be attributed to the larvicide. However, esterases only reflected indirect physiological effects of Bti, and further investigations are needed to identify biomarkers more specific of Bti endotoxins.  相似文献   
36.
Long  D 张莉 《海洋地质》2001,(2):68-80
穿过Barents海“火山口区”的多次调查资料的解释结果提供了该区火山口(大洼地,直径300-500m,深10-30m),与距今大约15000年冰消作用后气体逸出相关联的进一步证据。为山口的位置表明气体的流动受到三叠纪粉砂岩基岩断裂的控制。数个火山口内的地形高处(由棱角状的岩石组成,局部隆升于火山口壁围岩之上),被解释为水合物丘状体,说明了在火山口形成之后气体仍持续不断地流动。这可能是最早报道的在岩化沉积物中存在的水合物丘状体。假定这种气体为甲烷,海底温度与现今的相似,那么,当海底位于海平面之下280-340m时(比现今低10-80m)就会形成水合物丘状体。地化研究为紧邻火山口区海底浅层中气体水合物随季节性温度变化而分解这一论点提供了证据。  相似文献   
37.
Gastropods and bivalves were collected at 15 sites at Vancouver and Victoria, Canada between 24 May and 7 June, 1999, to establish tissue concentrations of butyltin and phenyltin compounds, to record imposex symptoms in gastropods, and to assess the present status of organotin contamination around Vancouver. No neogastropods (such as Nucella lima) were found around Vancouver. Neogastropod populations could have been extirpated by severe TBT contamination in Vancouver, as relatively high concentrations of TBT were detected in tissues of Mytilus trossulus from Vancouver, and the neogastropods distributed in Vancouver might be sensitive to TBT. Recovery from imposex, however, was observed in neogastropod populations from three sites at Victoria and Mission Point. TBT contamination has continued around Vancouver, arising from continuous use of TBT in antifouling paints for vessels larger than 25 m in length; however, TBT has decreased around Victoria and Mission Point. Different patterns of TBT accumulation in tissue were observed among the bivalve species from Vancouver. The highest TBT concentration detected in Tresus capax suggested some possible adverse effects. TBT was the most predominant butyltin component in almost all bivalve specimens surveyed, suggesting a low rate of TBT metabolism. Phenyltin compounds were not detected in any molluscan specimens in this study.  相似文献   
38.
In an attempt to learn more about the cytochrome P450 (CYP) system of mussels, we used protein databases and alignment software to extract highly conserved CYP sequences. From these alignments synthetic peptides were produced and used for rabbit immunisation, which yielded polyclonal antibodies against the CYP families 2 and 4. The antibodies were evaluated with Western Blot and ELISA assays, using digestive gland microsomal samples from the mussel Mytilus edulis. Western Blots revealed immunoreactions for both antibodies. The anti-CYP2 sequence rendered one major immunopositive protein of approximately 49 kDa size, and weak signals for proteins of approximately 41 and 56 kDa size. The anti-CYP4 sequence rendered two major bands of approximately 56 and 59 kDa size, and also a weak immunoreaction with a protein of approximately 43 kDa size. ELISA rendered only weak signals even with a 1:50 dilution of IgG-purified serum. A 10-day exposure to Aroclor 1254 did not appear to affect any of the immunopositive proteins, while total PCBs in soft bodies increased from 14-40 ng/g DW in controls to 373-638 ng/g DW in exposed mussels.  相似文献   
39.
We studied interactions of nitromusk compounds musk ketone and musk xylene and polycyclic musks Galaxolide trade mark (HHCB), Celestolide trade mark (ADBI), Tetralide trade mark (AHTN), and Traseolide trade mark (AITI) with multixenobiotic resistance (mxr) transporters in gill tissue of the marine mussel Mytilus californianus (Conrad, 1837). A competitive substrate transport test with rhodamine B was used to assay modulation of transport activity by musks. All tested musks inhibited the transport activity in the low microm range as indicated by increased accumulation of rhodamine B in the tissue. Compared to known substrates of mxr transporters, the effective concentration range was similar to quinidine and about 100 times higher than verapamil. Musk ketone and musk xylene also inhibited efflux of rhodamine B from gill tissue which was loaded with the dye and subsequently incubated with these compounds. Synthetic musk compounds are persistent environmental pollutants in aquatic environments with a high potential to bioaccumulate. As potent inhibitors of mxr transporters they may also play a role as chemosensitizers that enable toxic mxr substrates to accumulate in cells of aquatic organisms.  相似文献   
40.
一、引 言 由于地形性激发的中尺度重力波的中断,在加拿大气候中心大气环流谱模式中有时候采用了波的曳力效应的参数化。这一参数化的细节以及它在大气环流模式气候模拟中影响的讨论,可见Boer等人(1985)的工作。 最近,人们利用激发重力波次尺度地形的更好的描绘,来修改这一参数化方案。还有,使用Lindzen(1981)的波饱和概念来描述曳力效应。这一关于地形重力波曳力参数化的作法已在加拿大气候中心的大气环流谱模式中广泛试验,在加拿大气象中心的业务的谱数值预报模式中也正在普遍进行试验。本文的目的所在于概述在这些模式中正在普遍使用的波的曳力方案,并且证明这一方案在消除中期预报和大气环流模拟的系统性误差方面的用处。  相似文献   
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