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滨海电厂温排水停止排放以及季节更替、寒潮来袭等现象会引起海水温度降低,从而对鱼类等变温生物产生冷冲击效应。本研究通过模拟水温骤降情形,以孵化率、死亡率、畸形率等为指标,探讨了温度骤降对大黄鱼早期发育阶段(鱼卵和仔鱼)的冷冲击作用。研究发现,大黄鱼仔鱼(3日龄)对温度骤降的敏感性略高于鱼卵。在大黄鱼鱼卵和仔鱼的适温范围内,当水温由22 ℃骤降至19 ℃或16 ℃时,鱼卵的孵化率和死亡率无明显变化,而胚胎发育和仔鱼的生长发育均减缓,仔鱼的死亡率提高;水温超出适温范围,由22 ℃骤降至13 ℃或10 ℃时,对鱼卵和仔鱼造成致命的冷冲击伤害,48 h累积死亡率分别为84.6%~100%和72.1%~98.2%。由此推测:当水温骤降超出适温范围后,大黄鱼的早期发育阶段遭受致命的冷冲击伤害,从而影响种群补充和年龄结构。 相似文献
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P. L. Smart T. C. Atkinson I. M. S. Laidlaw M. D. Newson S. T. Trudgill 《地球表面变化过程与地形》1986,11(3):249-261
The relative advantages of fluorescent dyes and Lycopodium spores as tracers are discussed. The major advantage of fluorescent dyes is that they may be detected quantitatively. Thus, in combination with discharge measurements, a dye mass balance can be prepared for tracer tests in karst conduits, which permits elucidation of the underground network. The advantages of this procedure are illustrated by comparison of the networks derived from non-quantitative (Lycopodium and dye) and quantitative (fluorescent dye) tracer methods in the Traligill Basin, Scotland. These tests also suggest that Lycopodium does not give a true indication of travel time, due to sedimentation underground. This could also cause contamination problems in later tests. For non-quantitative tracer tests, sensitive methods are necessary if incorrect inferences on conduit networks are to be avoided. In general, however, quantitative tests give much less ambiguous results, and are therefore to be preferred. 相似文献
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S. T. Trudgill 《水文研究》1987,1(2):149-170
Three fluorescent dyes (Rhodamine WT, Lissamine FF and Amino G Acid) are compared for use in soil water tracing. Severe limitations are evident, but practical applications are possible. Background fluorescence, adsorption, desorption, pH and other non-adsorptive effects are reviewed in the contexts of soil column work and field tracing of soil water. Lissamine FF and Amino G Acid are to be preferred for soil column work because of their lower adsorption; Rhodamine WT exhibits higher adsorption but is useful in field situations where organic fluorescence backgrounds are high. Semi-quantitative work may be undertaken in soil columns once a priming and flushing procedure has been adopted. 相似文献
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综述了国内外工业废水与城市综合废水的监控和环境风险管理进展。与发达国家比较,化学监测法是目前我国工业废水和城市综合污水监控的唯一手段,而且主要有赖于COD等极少参数,并不能有效监控复合有毒有机污染物的排放。采用生态毒性检测法,可弥补这一缺陷,满足环境风险管理要求。毒性鉴别评价鉴别出导致废水/污水生态毒性的关键有机毒物,是降低其环境风险的核心。还对生态毒性检测法应用于我国废水/污水排放的监控和环境风险管理前景做了评述。 相似文献
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Pettersson M Hahlbeck E Katsiadaki I Asplund L Bengtsson BE 《Marine pollution bulletin》2007,54(12):1868-1880
The potential for endocrine disruption close to sewage treatment plant and pulp mill effluent discharge points along the Swedish Baltic Sea coast was explored using a dual survey strategy employing two stationary fish species. The levels of vitellogenin and spiggin as biomarkers of endocrine disruption were determined in juvenile three-spined sticklebacks (Gasterosteus aculeatus L.) together with the sex ratios and the presence of intersex. As an indication of exposure, estrogenic and androgenic substances were analysed by GC–MS in bile from perch (Perca fluviatilis L.). Spiggin and vitellogenin levels in juvenile three-spined sticklebacks were generally low, and, for most sampling sites no deviation in gonad type ratios were observed. No remarkable levels of natural or synthetic estrogens or androgens were observed in bile fluid from perch, while bisphenol A and 4-nonylphenol were detected in perch from both reference sites and exposed sites. Taken together, the results did not indicate estrogenic or androgenic disruption in the investigated waters. 相似文献
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M. Thangarajan 《Environmental Geology》1999,38(3):209-222
Palar River Basin, a crystalline rock region in North Arcot District (Tamil Nadu), India, possesses vast groundwater potential
along and near the river course and its lands are fertile. Serious contamination of both surface water and groundwater has
been reported in this basin as a result of uncontrolled discharge of untreated effluents by the tanning industries for the
last three decades. The health of the rural farming community and people working in the tanning industries has been seriously
affected and they are suffering from occupational diseases such as asthma, chromium ulcers and skin diseases. About an 11000
hectares area of fertile land has lost its fertility. Total dissolved solids (TDS) concentration in groundwater at some pockets
varies from 3000 to 10000 mg/l. As the discharge of effluents is continuing, a prognosis of further pollutant migration is
carried out using a mathematical model. A numerical model of the Upper Palar River Basin was developed using the finite difference
technique coupled with method of characteristics and used to predict TDS migration for the next 20 years. Sensitivity analysis
was carried out to identify the parameters which are influencing the contaminant migration. Sensitivity analysis shows that
advection and not dispersion is the predominant mode of solute migration in Palar Basin. Prognosis using the model confirms
that the polluted area zone as well as the concentration of pollutants in the groundwater will continue to increase in future.
The study also indicated that even if the pollutant sources are reduced to 25% of the present level, the TDS concentration
level in the groundwater, even after 20 years, will not be reduced below 50% of its 1992 level.
Received: 20 June 1998 · Accepted: 26 October 1998 相似文献
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