排序方式： 共有8条查询结果，搜索用时 31 毫秒
1
1.
Photo-protective functions were investigated in phytoplankton assemblages at Kongsfjorden, Svalbard in spring, using their UV-absorbing compounds (mycosporine-like amino acids (MAAs)), xanthophyll pigments (diadinoxanthin (DD) and diatoxanthin (DT)) and < beta >- dimethylsulphoniopropionate (< beta >-DMSP). The dominant phytoplankton species in the inner bay were dominated by Phaeocystis spp. and nanoflagellates, while the offshore waters were dominated by Thalassiosira spp. In the inner bay, UVabsorbing compounds and xanthophyll pigments exhibited higher ratios of MAA to chlorophyll a (MAA:chl a ratio), and both DD and DT to chlorophyll a (DD:chl a ratio and DT:chl a ratio), respectively. Thus, the photoprotective-pigments such as DD and DT appear to complement MAAs in the natural phytoplankton assemblage. However, the ratio of < beta >-DMSP to chlorophyll a (< beta >-DMSP:chl a ratio) did not show a distinct spatial distribution according to environmental factors or interspecies differences. In this study, we found that photoprotective compounds occurred in a manner dependent on the phytoplankton species composition in Kongsfjorden Bay, where Phaeocystis is the dominant species. 相似文献
2.
Simultaneous stabilization of arsenic, lead, and copper in contaminated soil using mixed waste resources 总被引：1，自引：0，他引：1
Keun-Young Lee Deok Hyun Moon Sang-Ho Lee Kyoung-Woong Kim Kyung-Hoon Cheong Jeong-Hun Park Yong Sik Ok Yoon-Young Chang 《Environmental Earth Sciences》2013,69(6):1813-1820
In the present study, stabilization treatment using waste resource stabilizers was performed for soil contaminated with As and heavy metals (Pb and Cu). Calcined oyster shell (COS) and coal mine drainage sludge (CMDS) were used as a mixed stabilizing agent for a wet-curing duration of 28 days. After the stabilization treatment, the treatment process efficiency was evaluated by the results of various batch- and column-leaching tests. Neutral and weak acid extraction methods, such as water-soluble extraction and SPLP, did not exhibit satisfactory results for heavy metal stabilization, even if they showed very low leachability. On the other hand, TCLP and 0.1 M HCl extraction showed that the stabilizers significantly reduced the amount of heavy metals leached from the soil, which strongly supports the thesis that the stabilization treatment is efficient in the acidic leaching conditions that were explored. Specifically, in the 0.1 M HCl extraction, the reduction efficiencies of As, Pb, and Cu leachings were more than 90 %, compared with control experiments. This study demonstrates that the application of waste resources for the stabilization of As and heavy metals is feasible. However, some limitations observed in the experiments should be considered in future studies, such as the mobilization of alkali-soluble elements, and in particular, exchangeable fractions of Cu. In addition, the treatment efficiency can be evaluated by different leaching methods, which suggests that multidirectional approaches are required for the proper evaluation of stabilization treatment. 相似文献
3.
Ocean Science Journal - The carbon isotopic compositions (δ13C) of n-alkanes in various environmental samples have been previously proposed as suitable fingerprints for assessing the origin of... 相似文献
4.
Sun-Yong Ha Hyong-Min Joo Sung-Ho Kang In-Young Ahn Kyung-Hoon Shin 《Journal of Oceanography》2014,70(1):1-10
We investigated the effects of ultraviolet-B (UV-B) radiation on the natural phytoplankton assemblage in Marine Cove on King George Island, Antarctica, in December 2005. The amount of newly synthesized phytoplankton polyunsaturated fatty acids (PUFAs) was lower with exposure to full irradiation (PAR+UV-A+UV-B) than without such exposure (exposed instead to PAR+UV-A radiation) in an in situ incubation under the light conditions in two different types of incubation bottles: quartz bottles transmitting all light wavelengths including UV-B and polycarbonate bottles with no UV-B transmission and 20 % reduced PAR compared to the quartz bottle. However, the amount of newly synthesized saturated fatty acids was greater with than without UV-B radiation. Thus, UV-B radiation may have a significant influence on fatty acid synthesis in phytoplankton. In particular, the production of eicosapentaenoic acid [20:5(n-3)] and docosahexaenoic acid [22:6(n-3)] was reduced during incubation under the natural solar radiation including UV-B. To understand the indirect influence of UV-B on herbivores (the secondary producer), we conducted feeding experiments with amphipods fed in situ on the natural phytoplankton assemblage. The amphipods fed on the phytoplankton with the low PUFA values also exhibited a low PUFA accumulation rate, which could negatively affect their growth, development, and reproduction. Consequently, the diminished rate of essential fatty acid synthesis [especially 20:5(n-3) and 22:6(n-3)] in primary producers caused by UV-B exposure could affect the structure and function of the Antarctic marine ecosystem. 相似文献
5.
Expression of superoxide dismutase (SOD) genes from the copper-exposed polychaete, Neanthes succinea
To evaluate the superoxide dismutase (SOD) genes as a potential indicator of environmental stress, we cloned and sequenced the full-length cDNA of a Cu/Zn-SOD and Mn-SOD genes from the marine polychaete, Neanthes succinea. Ns-Cu/Zn- and Mn-SOD expression was measured using quantitative real-time RT-PCR in response to the oxidative stress induced by copper in the form of CuCl2. Ns-Cu/Zn-SOD expression increased in a dose dependent manner but the increase of Mn-SOD expression was evident only at a high concentration of copper. Particularly, Ns-Mn-SOD dramatically increased in the 72 μg/L CuCl2-exposed groups, indicating that both Ns-SOD genes were induced by copper exposure. These results suggest that Ns-Cu/Zn- and Ns-Mn-SOD would play important roles in the detoxification of cellular oxidative stresses in the polychaete, N. succinea. Furthermore, as part of field work, the marine polychaete, N. succineaCu/Zn-SOD mRNA collected from the polluted area was accordingly upregulated in expression but not for NS-Mn-SOD. 相似文献
6.
Polychaetes are suitable organisms for evaluation of impact of sediment pollution. We evaluated toxicity of cadmium and copper and measured metallothionein-like proteins (MTLPs) in the polychaete Perinereis nuntia. At the same concentration ranges copper was unexpectedly more toxic than cadmium. Copper also caused no significant increase in MTLPs in the polychaetes. When P. nuntia and another polychaete species, Cirratulus cirratus were cultured in the contaminated sediments collected from Lake Sihwa (Korea), a high mortality of 80% was observed on day 6 in P. nuntia in the sediment with the highest metal concentration. However, no mortality was observed up to 35 days in C. cirratus in any sediment. MTLP contents between two species also varied. These findings suggest that MTLP induction response in the polychaetes varies with the metal type and species and it may be used as a biomarker of sediment pollution in the polychaetes after further validation and field trials. 相似文献
7.
Characterizing lipid biomarkers in methanotrophic communities of gas hydrate-bearing sediments in the Sea of Okhotsk 总被引：1，自引：0，他引：1
Jin-Yong Yang Kyung-Ho Chung Young-Keun Jin Kyung-Hoon Shin 《Marine and Petroleum Geology》2011,28(10):1884-1898
We studied specific lipid biomarkers of archaea and bacteria, that are associated with the anaerobic oxidation of methane (AOM) in a cold seep environment as well as the origin of sedimentary organic matter on the continental slope off NE Sakhalin in the Sea of Okhotsk. The organic geochemical parameters demonstrated that most of the sedimentary organic matter containing hydrate layers could be derived from marine phytoplankton and bacteria, except for a station (LV39-29H) which was remarkably affected by terrestrial vascular plant. Specific methanotrophic archaea biomarkers was vertically detected in hydrate-bearing cores (LV39-40H), coinciding with the negative excursion of the δ13Corg at core depths of 90–100 cm below the seafloor. These results suggest that methane provided from gas hydrates are already available substrates for microbes thriving in this sediment depth. In addition, the stable isotope mass balance method revealed that approximately 2.77–3.41% of the total organic carbon (or 0.036–0.044% dry weight sediment) was generated by the activity of the AOM consortium in the corresponding depth of core LV39-40H. On the other hand, the heavier δ13C values of archaeol in the gas hydrate stability zone may allow ongoing methanogenesis in deeper sediment depth. 相似文献
8.
To track the diet of minke whale (Balaenoptera acutorostrata) in the East Sea (Japan Sea), a conjoint analysis of fatty acids and C and N stable isotopes was performed on blubber and skin from the whale and its potential prey. The total lipid content in the blubber of minke whales ranged from 37.9% to 82.7% of wet mass (mean ± SD, 63.1 ± 17.2%), with triacylglycerols being the dominant lipids (96.9%–99.2% of total lipids). The lipid and fatty acid (FA) contents were systematically stratified throughout the depth of the blubber layers; contents of the dominant monounsaturated FAs (MUFAs), including 18:1ω9 and 16:1ω7, increased from the innermost layer to the outermost layer, whereas contents of saturated FAs (SFAs) and polyunsaturated FAs (PUFAs) were higher in the innermost layer than in the outermost layer. This stratification is related to the different physiological roles of the blubber layers; e.g., thermoregulation, streaming, and buoyancy. A comparison of the FA compositions of the innermost layer of minke whales with those of potential prey indicates that FA compositions in the whales are similar to those of Pacific herring. In addition, stable isotope ratios (δ13C and δ15N) suggest that minke whale and Pacific herring have the same or similar diets. Therefore, the diets of minke whale from the East Sea (Japan Sea) could be inferred from information on the diet of the Pacific herring, although FA compositions and stable isotope ratios for Pacific herring would not exactly reflect the whale’s diet. Although the very limited number of samples was used in this study, our preliminary findings are very promising to help understand the feeding ecology of minke whales in the East Sea (Japan Sea). 相似文献
1