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热带海洋全球大气计划的海气耦合响应试验(COARE)J.S.Godfrey(澳大利亚)1引言1992年11月-1993年2月,在巴布亚新几内亚以东地区进行了热带海洋全球大气计划(TOGM)的海气耦合响应试验(COARE),这是人们已进行的阵容最强的海... 相似文献
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Archaebacterially produced diphytanyl glycerol ether (DPGE) was examined in core sediments from the Orca Basin, an anoxic hypersaline basin in the northwestern Gulf of Mexico, to observe its spatial variability and potential origin. A differential extraction protocol was employed to quantify the isopranyl glycerol ethers associated with unbound, intermediate-bound, and kerogen-bound lipid fractions. Archaebacterial lipids were evident at all depths for the unbound and intermediate-bound fractions. Concentrations of DPGE ranged from 0.51 to 2.91 micrograms/g dry sediment at the surface and showed secondary maxima deeper in basin sediments. Intermediate-bound DPGE concentrations exhibited an inverse relationship to unbound DPGE concentrations. Kerogen-bound DPGE concentrations were normally below detection limits. Earlier studies describing the general homogeneity of lipid components within the overlying brine and at the brine/seawater interface suggest that the large-scale sedimentary DPGE variations observed in this study result from spatial and temporal variations in in situ production by methanogenic or extremely halophilic archaebacteria. 相似文献
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Previous studies showed that adult and 6-month-old young-of-year Fundulus heteroclitus from a polluted site have enlarged thyroid follicles and (in adults) higher thyroxine levels compared to fish from an unpolluted reference site. This study's purpose was to discover when in development these differences begin to appear. For 15-20 mm fish, the average follicle size of the polluted population was significantly larger than that of the reference population, similar to the pattern found in older fish. However, for the smaller size (12-14.5 mm), the average follicle size of fish from the polluted site was significantly smaller. Although not statistically significant, radioimmunoassay measurements of thyroxine levels were consistent with follicle differences: in larger sizes (20-25 and 15-20 mm) fish from the polluted site had higher thyroxine levels but the smaller size (12-14.5 mm) had lower levels. Therefore, the thyroid abnormalities seen in adults begin when the fish are approximately 15-20 mm long. However, the follicle size reversal for the 12-14.5 mm range may also indicate abnormality at that developmental stage. 相似文献
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Thorsson MH Hedman JE Bradshaw C Gunnarsson JS Gilek M 《Marine environmental research》2008,65(3):264-281
Settling organic matter (OM) is the major food source for heterotrophic benthic fauna. The high sorption affinity of many contaminants for OM implies that OM can influence both the distribution and bioavailability of contaminants. Here, we experimentally examine the role of settling OM of various nutritional qualities on the bioaccumulation of cadmium and the flame retardant BDE-99 by three benthic invertebrates; Macoma balthica, Monoporeia affinis and Marenzelleria sp. Contaminants were associated with three types of OM; a microalgae (Tetraselmis spp.), lignin and sediment. Bioaccumulation of Cd was proportional to OM nutritional quality for all three species, and was species-specific in the order Marenzelleria>M. balthica>M. affinis. BDE-99 bioaccumulation was highest in the treatment with the most nutritious OM (Tetraselmis). Consequently, both benthic species composition and the nutritive value of organic matter settling to the seafloor can have a substantial effect on the bioaccumulation of both metals and organic contaminants. 相似文献
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Wang T Lu Y Chen C Naile JE Khim JS Park J Luo W Jiao W Hu W Giesy JP 《Marine pollution bulletin》2011,62(8):1905-1914
Perfluorinated compounds (PFCs) in water, sediment, soil, and biota collected from estuarine and coastal areas of the north Bohai Sea, China, were determined by use of HPLC-MS/MS. Significant concentrations of PFCs were found in water (mean: 18.4 ng/l) and biologic samples (fish: 265 ng/g dw), while concentrations of PFCs in soils and sediments were less. The predominately detected compound was perfluorooctanesulfonate (PFOS), with a maximum concentration of 30.9 ng/l in water and 791 ng/g dw in fish. Concentrations of PFCs were significantly greater in the Liaohe River system than other locations, which suggests point sources in this urbanized and industrialized region. PFOS concentrations in water and biota were both less than the reported threshold concentrations. Detection of PFCs at relatively great concentrations in various environmental matrices from this region suggested that further studies characterizing concentrations of PFCs, their sources and potential risk to both humans and wildlife are needed. 相似文献
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