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1.
厦门潮间带泥滩和虾池小型底栖动物类群的丰度   总被引:12,自引:4,他引:12  
1996年对厦门三处潮间带和两口虾池的小型底栖动物进行了调查。结果表明,小型底栖动物主要类群自由生活海洋线虫。此外,还有底栖桡足类、多毛类和寡毛类。三处潮间带海洋线虫的平均密度为60.13个/cm^2,占小型底栖动物平均密度的94.46%。除了鸡屿中潮区和低潮区外,其他潮漳带海洋线虫与底栖桡足类丰度比度多在16.3以下,表明厦大海边和大屿潮间带未受明显污染。刚放虾苗的虾池,小型底栖动物贫乏,随着时  相似文献   
2.
Many beaver ponds in the Rocky Mountains, that have been described in the literature, are in‐channel ponds that are relatively small and short‐lived. This paper describes floodplain beaver ponds on low‐gradient deltas in glacial finger lakes in Glacier National Park, Montana. These ponds are distinctly larger, probably fed by hyporheic flow, and stable and long‐lived. Ponds examined were, with one exception, 44 years old. Glacial discharge is present in each valley where beaver ponds occupy low‐gradient deltas, and this discharge likely sustains pond water level over the course of the summer. As glaciers recede and disappear, deltaic beaver ponds dependent on hyporheic flow may be negatively affected. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
3.
初步研究了在海参养殖池塘中,不同养殖方式下,大型海藻海黍子(Sargassum muticum)的生长特性及对水体中氨氮和活性磷的去除作用。2012年3~5月,在山东莱州试验养殖海黍子60d,结果发现其长度最大从43.8cm增长到81.3cm,增长85.6%,日增长率(SGR)在14℃时最大,达到5.0%;每绳的平均质量从0.74kg增到2.59kg,增长3.5倍,SGR在12℃时最大,达4.3%;水体氨氮平均下降了25.9%,活性磷下降了37.5%。实验证明海黍子能在适合的池塘中养殖,并且能有效的去除水体中的氨氮和活性磷,是有效的近海生境修复大型工具种海藻。  相似文献   
4.
采用池塘中设置生物膜净水栅对比实验的方法,在8口土池开展生物膜"细菌-藻类"协同系统改良池塘养殖水质与沉积物的效果、对苗种培育效果的影响及其相关机理等的研究。结果表明,在142d的养殖期间,处理组比对照组节水减排达65.1%,具有极显著差异(P0.01);处理组水质的p H、总氮和亚硝酸盐氮分别极显著低于对照组3.7%、31.3%和38.7%(P0.01),氨氮、总磷、活性磷和硫化物分别显著低于对照组25.6%、41.6%、37.8%和27.9%(P0.05);弧菌数和藻类密度极显著低于对照组63.1%和51.3%,硅藻相对密度极显著高于对照组93.7%;细菌总数显著高于对照组50.8%,蓝藻相对密度显著低于对照组16.6%;处理组的藻类生物均匀度指数显著高于对照组8.9%;生物膜上的细菌总数高达1.30×109 CFU/g,而弧菌数为零;处理组池塘沉积物的氧化还原电位显著高于对照组30.5%,硫化物浓度显著低于对照组47.0%;草鱼苗种起捕规格、成活率、产量和生长速度分别显著高于对照组24.6%、4.3%、29.8%和28.6%,饲料系数极显著低于对照组15.6%,处理组每公顷池塘培育草鱼大规格鱼种可增加净利润约1.92万元。  相似文献   
5.
虾池生态系能流结构分析   总被引:2,自引:1,他引:2  
阐述虾池生态系的能流结构,将虾池生态系分为两个亚系统:浮游亚系统与底栖亚系统,在浮游亚系统中有3个功能群,底栖亚系统中有5个功能群。系统的能量来源为人工投饵和太阳光。研究分析两个亚系统中各个生物状态变量的公式表达及其在系统中的功能,阐明了能量在系统中的流动方向和公式表达。浮游亚系统与底栖亚系统通过POC的沉降过程以及营养盐在沉积物中的生物地化循环再生后,经由水/底界面进入水体而耦合。  相似文献   
6.
厦门同安西柯对虾养殖池的细菌数量动态   总被引:10,自引:0,他引:10  
本文研究了对虾养成期间养殖池生态系中细菌的数量动态,探讨其变化规律与虾病的关系。结果表明,总细菌、弧菌和发光细菌在水体、底质和虾体中的数量变化各异。在水体各菌数与其环境因子的关系中,除了总菌数与COD存在着正相关外,其它的不存在相关性。虾体的总细菌、弧菌和发光细菌的数量(以细胞计)可以用来预报虾病,三者的阅值分别为107个 /g(湿重)、105个/g(湿重)和104介/g(湿重)。通过对对虾的细菌学跟踪监测,可以及时采取有效的应急防治措施。  相似文献   
7.
The near-to-nature approach has been established as best practice for stormwater management. However, pollutant mobility within such systems and its impact on small receiving waters are partly unexplained. The study takes place in an urbanised headwater catchment in south-western Germany with an area of 0.4 km2. Runoff from roofs, roads, parking lots and gardens is collected in wells or trenches and stored in private and public dry detention basins. Accordingly, this study investigates pollutant input to a detention pond, removal efficiency and the associated effects on the receiving water.Grab samples with high temporal resolution of the receiving water (16 flood events with 315 samples and 41 baseflow samples), the three inflows of the detention basin and its outflow (four flood events with 64 samples) were taken. The outflow of the dry pond is recovered in the hydro- and chemographs of the receiving water. Runoff from roads with increased traffic volume caused the highest PAH inputs and runoff from the residential area showed the highest zinc concentrations, which partly infringe European Environmental Quality Standards. Yearly pollutant inputs (DOC, TSS, PAH, nutrients, metals) from the settlement into the tributary are reduced in the detention pond by up to 80%.  相似文献   
8.
Thermal impact of typical high‐density residential, industrial, and commercial land uses is a major concern for the health of aquatic life in urban watersheds, especially in smaller, cold, and cool‐water streams. This is the first study of its kind that provides simple easy‐to‐use equations, developed using gene expression programming (GEP) that can guide the assessment and the design of urban stormwater management systems to protect thermally sensitive receiving streams. We developed 3 GEP models using data collected during 3 years (2009–2011) from 4 urban catchments; the first GEP model predicts event mean temperature at the inlet of the pond; the second model predicts the stormwater temperature at the outlet of the pond; and the third model predicts the temperature of the stormwater after flowing through a cooling trench and before discharging to the receiving stream. The new models have high correlation coefficients of 0.90–0.94 and low prediction uncertainty of less than 4% of the median value of the predicted runoff temperatures. Sensitivity analysis shows that climatic factors have the highest influence on the thermal enrichment followed by the catchment characteristics and the key design variables of the stormwater pond and the cooling trench. The general method presented here is easily transferable to other regions of the world (but not necessarily the exact equations developed here); also through sensitivity and parametric analysis, we gained insight on the key factors and their relative importance in modelling thermal enrichment of urban stromwater runoff.  相似文献   
9.
Chlorophyll pigments (CHL), primary productivity (PP) and particulate nitrogen (Np) in relation to several environmental factors were monitored during planktonic colonization of an aquaculture pond (Layo, Côte d'Ivoire). How interactions between the organisms are established in an initially azoic environment were investigated. From March, 15 (D1) to March, 31 (D16), the system transformation went through three stages. First, a precolonization by heterotrophic microbial community from D1 to D2 (Np < 1 m maximum at D2: 243 mg m–2; CHL around 0). Then, a pioneer microalgal community developped from D3 to D7 (maximum CHL on D6: 19 mg m–2; PP: 1.0 g C m–2 d–1) with a significant contribution of picoplankton (CHL and PP < 3 m: 33 and 23% of the total, respectively). Finally, a second microalgal colonization was noticed from D9 to D12 (maximum CHL: 55 mg m–2, PP: 2.8 g C m–2 d–1), largely dominated by nanoplankton (CHL and PP > 3 m: 95 and 99% of the total, respectively). Overall, photosynthetic activity appeared to be closely linked to algal biomass. The study of autotrophic biomass and activity in different size classes in relation to the other parameters allowed us to precise the origin of the biomass fluctuations. The first bloom appeared to be controlled by selective grazing on small algae. The second algal development ended when N requirement represented at least 69% of N supply (in the N — NH4 form). This control was enhanced by the appearance of rotifers, leading to a more complex equilibrium.  相似文献   
10.
Seismo-tectonic areas of historical strong earthquakes with M S≥7 along Xianshuihe-Xiaojiang fault zone are divided, and their individual fault-pattern and tectonic geomorphology are analyzed. Those strong-earthquake areas are located in some special parts of the fault zone, where the major branch-faults of the fault zone form left stepping, parallel, and fork-like patterns. In the strong-earthquake areas structurally complicated basins are developed, such as pull-apart basins in fork-like area, in double stepping area, and in stepping and fork-like areas. Foundation item: Chinese Joint Seismological Science Foundation (9507424). Contribution No. 2001A003, Institute of Crustal Dynamics, China Seismological Bureau.  相似文献   
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