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1.
In this study, 36 fish species were collected from three coastal cities in Korea to investigate levels and patterns of six arsenicals (arsenite: As (III), arsenate: As (V), arsenocholine: AsC, arsenobetaine: AsB, monomethylarsonic acid: MMA, and dimethylarsinic acid: DMA). The levels of ∑6 As in the different fish species varied substantially, ranging from 0.02 μg As/g ww (Islaeli carp) to 9.65 μg As/g ww (Skate ray) with a median of 0.40 μg As/g ww. All the arsenicals in marine fishes showed higher levels than those in freshwater fishes due to fish feed living in saline water. Overall, marine carnivorous fishes seem to be more contaminated with arsenic. For all the fish samples, AsB (mean fraction: 90.6%) was dominant among the six arsenicals, indicating biomethylation of inorganic arsenic and accumulation of AsB. Fish species with high water contents showed elevated levels of As (III), but there was no further significant correlations between arsenicals and water/lipid contents. Concentrations of As (V) were significantly lower than those of As (III), which implies that As (V) is reduced during biomethylation of inorganic arsenic. Consequently, we hypothesize that the toxicity of arsenic (mainly derived from As (III)) can be increased by the reduction of As (V), especially for the fish species with higher water contents. 相似文献
2.
Dennis G. Waslenchuk 《Marine Chemistry》1978,7(1):39-52
The concentrations of arsenic species in continental-shelf waters of the southeastern U.S. are controlled mainly by simple physical mixing of shelf waters and Gulf Stream intrusions. The biota mediate redox reactions which result in a disequilibrium of arsenic species; up to 20% of the total arsenic (averaging 1.1 μg/l) occurs as unstable arsenite [As (III)] and dimethylarsenic, the remainder consists of thermodynamically favored arsenate [As (V)]. Uptake of arsenic by the biota has a minor effect on arsenic distribution in offshore waters, producing a deep-water arsenate maximum, and minima for arsenite and dimethylarsenic. Riverine and atmospheric arsenic inputs to the shelf waters are relatively insignificant. Southeastern rivers contain only about 0.3 μg/l dissolved arsenic, and the atmosphere adjacent to continental shelf waters contains about 1.7 ng/m3 of As (V), exclusively associated with the particulate fraction. 相似文献
3.
Total arsenic, arsenate and arsenite concentration profiles for the water column of Saanich Inlet, an intermittently anoxic fjord located on Vancouver Island, B.C., Canada, were measured using independent analytical techniques for total arsenic and arsenic speciation to evaluate the accuracy of the speciation technique in both oxic and anoxic marine environments. Total arsenic profiles indicate a mid-depth minimum of about 1.0 ppb above the oxic—anoxic interface and an enrichment in the anoxic zone to about 2.0 ppb. This minimum may be due to either advection of arsenic-poor water into Saanich Inlet at mid-depth or arsenic incorporation onto solid phases within a bacteria- and manganese-rich particulate layer located immediately above the oxic—anoxic interface and subsequent removal via sinking particulate material. Ratios of total arsenic to phosphorus in the deep, anoxic waters of the basin are similar to those reported for marine algae, suggesting that the enrichment of total arsenic within the anoxic bottom layer may be due to its release upon organic matter decomposition.Arsenate and arsenite concentration versus depth profiles indicate a rapid (but incomplete in a thermodynamic sense) response to the oxic—anoxic interface. The arsenate/ arsenite concentration ratio is 15/1 in the oxic region of the water column and 1/12 in the anoxic zone. Arsenate—arsenite interconversion occurs at a depth shallower than ferric-ferrous but deeper than MnO2 —Mn2+ interconversions.Measurements of arsenite oxidation rates at near-ambient arsenite concentrations and temperatures using an 74As3+ radioactive tracer technique indicate that arsenite oxidation is initially ten times faster in seawater taken from the manganese-rich particulate layer at 165 m depth than in seawater collected near the surface at 50 m depth. Addition of antibiotics to seawater from 165 m depth initially suppressed the rate of arsenite oxidation, indicating that it may be partially microbially mediated. 相似文献
4.
Sensitive methods for the determination of arsenate and particulate arsenic (PAs), as well as phosphate and particulate phosphorus (PP), in seawater are described. The method for arsenate and phosphate was established by applying automated liquid waveguide spectrophotometry. Because the reaction time for the formation of the arsenate-molybdate complex is longer than that for the phosphate-molybdate complex, a long Teflon tube submerged in a heating bath was installed in the conventional phosphate flow system. The arsenate was quantified as the difference between absorbances of molybdenum blue dyes with (only phosphate) and without (phosphate + arsenate) arsenate reduction treatment. Contamination was observed in the reagent for arsenate reduction and must be corrected. Linear dynamic ranges up to 1000 nM were confirmed for arsenate and phosphate. The detection limits for arsenate and phosphate were 5 and 4 nM, respectively. Freezing was a reliable sample preservation technique for both arsenate and phosphate. The method for PAs and PP was established by combining conventional persulfate oxidation of PP and the automated liquid waveguide spectrophotometry of arsenate and phosphate. The digestion efficiencies of organic As analogs were >93%. Contamination in the glass fiber filter was negligible. Field tests confirmed that the coefficients of variation (CVs) of 10–19 nM arsenate and 4–151 nM phosphate were 7–20 and 1–25%, respectively, while the CVs of 0.9 nM PAs and 10.2 nM PP were 11 and 4%, respectively. 相似文献
5.
6.
James G. Sanders 《Marine environmental research》1980,3(4):257-266
The arsenic cycle in productive, near-shore marine systems is complex, involving both geochemical inputs and outflows and biological mediation. The major input to the Georgia Bight is intrusion of subsurface Gulf Stream water; in other marine systems, river run-off and atmospheric deposition may provide a large percentage of the arsenic input. Indiscriminate biological uptake is responsible for changes in arsenic speciation, involving approximately 20% of the dissolved arsenate pool and resulting in measurable concentrations of reduced and methylated arsenic species. The overall cycle is similar to the phosphate cycle; however, regeneration time for arsenic is much slower. 相似文献
7.
An unusual feature has been observed in polychaetes regarding their capacity to accumulate high levels of relatively toxic forms of arsenic in specific tissues. Basal levels of arsenic and distribution of its compounds were investigated in tissues of the Mediterranean polychaete Sabella spallanzanii. Particularly high concentrations were measured in the branchial crown (1036+/-136 microg/g d.w.) and chemical speciation revealed that the predominant form was the relatively toxic dimethylarsinate (DMA). These data suggest a potential role of As as anti-predatory strategy in polychaetes. 相似文献
8.
Axenic cultures of the microalgae species, Dunaliella tertiolecta and Phaeodactylum tricornutum were grown at arsenic (As) concentrations typically found in uncontaminated marine environments ( 2 µg L− 1) under different phosphorus concentrations. D. tertiolecta accumulated higher arsenic concentrations (mean: 13.7 ± 0.7 µg g− 1 dry mass) than P. tricornutum (mean: 1.9 ± 0.2 µg g−1 dry mass). Media phosphorus concentrations (0.6–3 mg/L) had little influence on microalgae growth rates or arsenic accumulation. Arsenic was present as lipid bound (29–38%; 4.2–9.5%), water-soluble (20–29%; 26–34%) and residue bound (41–45%; 57–69%) arsenic species in D. tertiolecta and P. tricornutum respectively. Hydrolysed lipids contained mostly glycerol arsenoribose (OH- ribose), dimethylarsinate (DMA) and inorganic arsenic (As(V)) moieties. Water-soluble species of microalgae were very different. D. tertiolecta contained inorganic arsenic (54–86%) with variable amounts of DMA (7.4–20%), arsenoriboses (5–25%) and traces of methylarsonate (MA) ( 1%). P. tricornutum contained mostly DMA (32–56%) and phosphate arsenoribose (PO4-ribose, 23–49%) and small amounts of OH-ribose (3.8–6.5%) and As(V) (9–16%). Both microalgae contained an unknown cationic arsenic species. The residue fractions of both microalgae contained predominately inorganic arsenic (99–100%). These results show that at natural seawater arsenic concentrations, both algae take up substantial amounts of inorganic arsenic that is complexed with structural elements or sequestered in vacuoles as stable complexes. A significant portion is also incorporated into lipids. Arsenic is metabolised to simple methylated species and arsenoriboses. 相似文献
9.
本文综合2000～2003年期间9个航次的研究结果，讨论了总溶解态无机砷（TDIAs，[TDIAs]=[As^5＋]＋[As^3＋]）和亚砷酸盐（As^3＋）在黄、东海的分布和季节性变化。调查海区覆盖了黄、东海不同水文和化学性质的区域，研究重点放在自长江口向东南琉球群岛沿伸的PN断面以讨论陆源输送的物质对中国陆架边缘海的影响。利用氢化物发生原子荧光光谱法（HG-AFS）分析砷的不同形态（TDIAs，As^3＋）。TDIAs受河流陆源输送的影响在近岸区域含量较高，并随着离岸距离的增加含量逐步下降。在东海陆架坡折带的近底层水中也存在TDIAs的高值中心，此区域具有低温、高盐、低悬浮颗粒物含量的特征，显示出入侵陆架的黑潮水是陆架区TDIAs另一个主要的源。TDIAs的季节性变化趋势受到长江冲淡水水量及黑潮入侵陆架强度的季节及年际变化共同影响。研究区域中As^3＋的分布特征与TDIAs相反，其含量、分布及季节性变化受到浮游植物活动的影响，表现出与叶绿索含量存在正相关关系。夏季东海陆架PN断面中As／P的化学计量比值约为2×10^3。黄、东海溶解态砷的含量与世界其它海区相近，表明其未受到明显人为活动的影响。 相似文献
10.
《Oceanologica Acta》1998,21(2):325-333
The arsenic (As) cycle in the marine environment is known to be sensitive to biological activity. Within the scope of the National Coastal Oceanography Program, we undertook a specific study of the behaviour of this element in a water column on the continental shelf of the Bay of Biscay off the Gironde estuary during two oceanographic cruises conducted in May 1994 and May 1995. Various chemical forms were measured: arsenate (As3), arsenate (As5), monomethylarsenic (MMA), dimethylarsenic (DMA) and dissolved total As after ultraviolet mineralization. The net flux of total As from the Gironde estuary was evaluated as well as its effect on the concentration in surface marine waters. The vertical profiles in the coastal zone during a period of active primary production confirmed a certain analogy between arsenates and phosphates as well as the formation of As3 and DMA. The importance of organoarsenic species not directly accessible to the formation of volatile hydrides is demonstrated. Their presence modifies assessments, reducing the deficit of dissolved total As in the euphotic layer to just 5%. For particles, the As content in phytoplankton was estimated at 6 μg·g−1 compared to 20 to 30 μg·g−1 in iron- and aluminium-rich terrigenous particles. These results do not invalidate the role of phytoplankton in the speciation of dissolved As but indicate that their involvement in vertical transfers was apparently not predominant in the zone under study. 相似文献
11.
Shiro Gohda 《Journal of Oceanography》1974,30(4):163-167
The content and the oxidation state of arsenic and antimony in coastal seawater were determined coupled with chemical separation and neutron activation method. The contents of arsenic and antimony in coastal seawater were estimated to be 1.56–2.73g As/l, 0.25–0.57g Sb/l. Most parts of these elements exist as soluble ionic species, passing through 0.45 pore-size membrane filter, and at surface, 80–97% of arsenic occurs as arsenate and 70–94 % of antimony may occurs as antimonate. The vertical distribution of arsenite and arsenate is almost constant from the surface to 1,200 m depth. However the distribution of Sb(III) and Sb(V) is much more complicated with depth. 相似文献
12.
Marine Mangrove Fungi 总被引：5，自引：0，他引：5
Abstract. Driftwood, prop roots and other mangrove samples were collected from the intertidal regions of Brillant and Anse Boileau mangrove stands, in the Seychelles. This material was examined for the presence of higher marine fungi. Forty seven species of marine fungi were collected (37 Ascomycotina , 1 Basidiomycotina, 9 Deuteromycotina) , with Halocypluna villosu the most common fungus, while Aniptodera mungrovii, Antennospora quudricorruita, Halosarpheia marina , Ascomyccte sp. (4), and Lulworthiu grandispora were collected frequently. The mycota of the two mangrove stands arc compared. A list of fungi recorded from mangroves is compiled. 相似文献
13.
Arsenic geochemistry in Chesapeake Bay: Dependence upon anthropogenic inputs and phytoplankton species composition 总被引：1，自引：0，他引：1
James G. Sanders 《Marine Chemistry》1985,17(4):329-340
Arsenic is not conservative in Chesapeake Bay. Inputs of man-derived arsenic, of the order of 100 kg d−1, cause substantial positive deviation from theoretical dilution. The chemical form of the arsenic varies both seasonally and along the axis of the bay. During winter, arsenic is present only as arsenate. During summer, substantial quantities of reduced and methylated forms are present in different areas, indicative of separate formation processes. Arsenite, present in low-salinity regions, may have been formed by chemical reduction in anoxic, subsurface waters and then mixed into the surface layer. Methylated arsenicals correlate highly with algal standing stocks. One particular form, methylarsonate, is highly correlated with the dominant algal genus, Chroomonas. As both arsenic reactivity and toxicity are altered by transformation of chemical form, the observed variations in arsenic speciation have considerable geochemical and ecological significance. 相似文献
14.
The uptake of polycyclic aromatic hydrocarbons (PAHs) by marine deposit-feeding invertebrates can be determined by screening for PAH-derived metabolites. We identified 1-hydroxypyrene as the only intermediate metabolite in tissue of four species of deposit-feeding polychaetes, Nereis diversicolor, Nereis virens, Arenicola marina, and Capitella sp. I exposed to pyrene spiked sediment. Synchronous fluorescence spectroscopy (SFS) provides a fast and simple method for both qualitative and quantitative analysis of 1-hydroxypyrene in all four species. The SFS assay was validated using HPLC with ultraviolet detection. A good correlation between 1-hydroxypyrene concentrations determined by the two methods was observed. We used HPLC with fluorescence detection combined with enzymatic hydrolysis of conjugated metabolites to investigate species specific metabolite patterns. A tentative aqueous metabolite identification scheme indicates that Nereid polychaetes predominately make use of glucuronide conjugation whereas Capitella sp. I. and Arenicola marina appear to utilize predominantly sulfate and/or glucoside conjugation. The usefulness of 1-hydroxypyrene as a biomarker for PAH exposure in deposit-feeding invertebrates is discussed. 相似文献
15.
The distribution of dissolved and participate concentrations of As, Cr and V was investigated in the mixing area of the Po river in five surveys over the period March 1992-March 1995. The data obtained indicate noticeable contamination of coastal waters of the northern Adriatic with Cr but not As or V. Total dissolved concentrations for As and V were comparable with oceanic levels but were higher by a factor of 4 for Cr. These results suggest either low anthropogenic inputs of As and V, from terrigenous and atmospheric sources, or efficient removal mechanisms. The investigated metals had low reactivity during freshwater-seawater mixing and the distribution of concentrations in the dissolved and solid phases suggests that the dilution process is the main factor controlling the transport of these metals to the sea in low-to-medium solid transport conditions. Further investigations are required to elucidate the behavior of these metals during high solid transport conditions. Significant changes in the speciation of As occurred during the transition between the two end-member matrices. In the coastal waters of the northern Adriatic, the arsenite fraction in winter, and the arsenite and dimethylarsinate fractions in summer increased with respect to riverine waters. Changes in the speciation of chromium were minor, but also showed a small increase in reduced species in marine waters. 相似文献
16.
R.J. Morris M.J. McCartney A.G. Howard M.H. Arbab-Zavar J.S. Davis 《Marine Chemistry》1984,14(3):259-265
Dissolved inorganic arsenic and phosphate levels present in an enclosed experimental ecosystem have been studied during the course of a natural spring diatom bloom. Whilst phosphate levels dropped rapidly to almost zero as the bloom developed, arsenic levels remained constant even when arsenate levels exceeded the dissolved phosphate. Certain diatom species (Thalassiosira spp., Chaetoceras spp. and Skeletonema costatum) therefore appear to be capable of discriminating, either by uptake or excretion, between phosphate and arsenate. The implications of such findings are discussed. 相似文献
17.
Zosteramarina, a monocotyledonous angiosperm, is one of themost important seagrass species. To investigate the salt-tolerancemechanismand discover salt-tolerant genes in Z. marina, a cDNA library was constructed. Single-pass sequencing of the 5' ends of 4 081 clones yielded 4 002 high quality expressed sequence tags (ESTs), which were assembled into 241 contigs and 1 673 singletons, representing 1 914 unigenes. The average length of the ESTs was 582 bp, with sizes ranging from100-1 500 bp. Basic Local Alignment Search Tool (BLASTX) analysis revealed that 1 664 unigenes had significant homology to known genes in the National Center for Biotechnology Information (NCBI) non-redundant (nr) database (E-value≤5-10). Among them, the twomost abundant genes encoded metallothionein (157 ESTs) and chlorophyll a/b-binding protein (38 ESTs), accounting for 7.1% and 1.7% of the total ESTs, respectively. Using Kyoto Encyclopedia of Genes and Genomes (KEGG), 1 462 unigeneswere assigned to 1 161 pathways (E-value≤5-10). A total of 938 unigenes were assigned Gene Ontology (GO) terms based on the GO hierarchy analysis, and InterProScan searches recognized 1 003 InterPro families. Three genes formetallothionein in Z. marina that belonged to Class II was identified. Results of this study will improve understanding of the molecular mechanisms of saline tolerance in Z.marina. 相似文献
18.
九龙江口秋茄和白骨壤的渗透调节剂及其贡献 总被引：9，自引：0，他引：9
于1994年和1995年,在福建省九龙江口龙海市海岸采集秋茄和白骨壤样品,采用原子吸收分光光度法、而定法和比色法分析了其叶片组织中无机和有机渗透调节剂的含量及其贡献。结果表明,秋茄和白骨壤的无机渗透调节剂在总渗透调节中的贡献分别为87.8％和87．4％,有机渗透调节剂的贡献仅分别为12．2％和12．6％。在无机渗透调节剂中,Na 和Cl-占主导地位,其次为K ,而Ca2 、Mg2 和NO3-的贡献很小。在有机渗透调节剂中,可溶性糖占主导地位,游离氨基酸和有机酸的贡献较小。另外,秋茄和白骨壤根据分析的无机和有机渗透调节剂浓度计算出的渗透调节能力均小于实测值,说明存在其它一些未知的渗透调节剂。 相似文献
19.
大叶藻是一种水生单子叶植物,是构成海草床的主要藻类之一。对大叶藻内生放线菌及其活性物质的研究是发现海洋微生物资源和新天然产物的有利途径。通过纯培养的方法,使用2216E等7种培养基,从山东省威海市荣成天鹅湖采集的大叶藻样品中分离出62株内生放线菌,并利用纸片法对金黄色葡萄球菌、白色念珠菌和副溶血性弧菌等7种指示菌进行了抗菌活性筛选,其中RO培养基分离出放线菌的种类和数量都较为丰富。抗菌活性筛选结果表明,48株内生放线菌(占77.42%)至少对1种指示菌表现出一定的抑制作用,36株内生放线菌(占58.06%)抑制2种及2种以上指示菌;并且内生放线菌对革兰氏阳性指示菌(金黄色葡萄球菌和枯草芽孢杆菌)的抗菌效果明显优于革兰氏阴性指示菌。研究结果表明,大叶藻的内生放线菌具有较好的抗菌活性,可以为海洋来源抗生素的研究提供新资源。 相似文献
20.
Gerhardt F. Riedel James G. Sanders Richard W. Osman 《Estuarine, Coastal and Shelf Science》1987,25(6)
From the distribution of dissolved and solid arsenic species in a contaminated estuarine sediment and measured rates of flux of the various arsenic species we propose an empirical model for the cycling of arsenic between sediments and water column. The chemical form of arsenic in the sediment was largely determined by the redox state of the sediment. Arsenite was the dominant dissolved and solid species in the deeper reduced sediment, and arsenate was dominant in the oxidized surface layer. Arsenite in the interstitial water diffused toward the surface layer, where it was mostly oxidized to arsenate prior to leaving the sediments. Some arsenate adsorbed to the surface sediments and produced a surface layer enriched in arsenic. Small concentrations of methyl and dimethyl arsenic were produced in the sediments, and these also diffused into the overlying water.Nereis succinea, a burrowing polychaete, affected distribution and flux of arsenic from the sediments by its production of irrigated burrows. These burrows increased both the effective surface area of the sediment and the diffusion of arsenic by a factor of five. When the relative effects of the activities of Nereis succinea and physical resuspension are compared, results indicate that although physical resuspension can produce large pulses of materials from contaminated sediments, continuous biological activity is likely to be more important in the mobilization of contaminants from sediments in many estuarine environments. 相似文献