飞来峡建库蓄水对底栖生物的影响

一、库区底栖生物底栖生物是指长时期栖息于水底的生物,一般指动物,如园形动物、环节动物、软体动物、节肢动物等,它们对人类的关系,除少数种类可供人类食用外,一般常作为鱼饵,在环境监测工作中,常以底栖生物的种群、群量,指示水质的好坏程度.

水体污染与水生生物研究

现在经常提到“生物圈”这一名词。“生物圈”是指地球的有生物居住的气体层、液体层、和固体层而言。由于液体层(即水圈)的化学和物理性质对生物非常有利,所以生物非常丰富。从水体表面一直到一万多公尺深海处都有生物存在。水中有些什么生物呢?有:浮游生物、游泳生物、漂游生物及水底生物;而水底生物、根据它们的生活方式,又可分为底栖生物等很多种。

泥沙与河流水生生境

本文综述了有关泥沙与河流水生生境相互联系的研究成果和研究现状．河流的物理变化主导着水生生境的特性及其变化．采用工程技术方法．可以在一定程度上评估和预测水生生境的状况；根据占主导地位的河道床沙类型——漂卵石、卵砾石、沙质还是细沙．可以对河流及其所维持的水生生境进行分类：推移质级配一旦接近床沙级配，水底生物的物种数量将会减少：泥沙不仅为鱼类提供了庇护和产卵场所。而且还为鱼类的食物生物提供了栖息地；作为鱼类生境特性的一个间接指标。泥沙反映了水深和流速的某种瞬时组合；其它与河流输沙有关的主要生境问题包括：有机物颗粒输移，水质与泥沙相互影响，细颗粒泥沙在粗颗粒淤积物之上和之中淤积，以及主河槽相临缓流区淤积等；大多数河流生物可以忍受短期地处于高含沙水流环境之中，但长期地处于这一环境之中是十分有害的。

Bioturbation Effects of Benthic Fish on Soil Microorganism of Paddy Field

[Objective]The research aimed to explore the bioturbation effects of benthic fish Misgurnus anguillicaudatus on soil microorganism（microflora,biomass,and special physiological groups） of paddy field.[Method]The experiments were conducted locally and quantitatively in field,using plate count and MPN methods.[Result]In the microflora of paddy soil tested,the quantity of bacteria is the largest,followed by actinomycetes and fungus.Compared with the control paddy fields,in rice-fish paddy fields the quantities of bacteria,actinomycetes and fungus were higher,at significance level P 〈0.05,P 〈0.01,and P 〈0.01 respectively.The microbial biomass C and N in rice-fish paddy fields is remarkably higher than those in control paddy fields,both at significance level P 〈0.01;the microbial biomass P in rice-fish paddy fields is higher than that in control paddy fields,but at significance level P 〈0.05.Benthic fish promotes the growth of soil azotobacter,cellulolytic bacteria,nitrobacteria,sulfur bacteria,and ammonifying bacteria,restricts the reproduction of nitrate reducing bacteria and sulfate reducing bacteria.[Conclusion]The benthic fish had important effects on microflora,microbial biomass,and special microorganism physiological groups of paddy soil,improves the living conditions of soil microorganisms,promotes the soil fertility and bio-chemical activity,which is beneficial for improving the supply ability of soil nutrients such as N,P,S,as well as the efficiency of nutrient utilization.

眺望东京湾

日本东京湾的形成,是在大约1.2万年前即冰川时代结束后的时期。今天,东京湾出产的鱼货仍被称为“江户前”。5000年前留存下来的贝冢说明了这一带海区自古以来就盛产海生物,它为人们提供丰富的食物原料。在东京湾,有着面积约70米~2的珊瑚礁。而东京湾的珊瑚礁则是同类中最大的且位于最北端。珊瑚礁分布在近邻东京湾口的千叶县锯南町胜山地区的水深不到10米的沿岸区域,在岸上也能清楚地看到水中珊瑚。

巧用食草 动物除草

植物保护学家近年来研究利用草食动物清除农田杂草的方法,可以节省大量饲料,发展养殖业,可谓一举多得。 南美洲的一些农场主,为了清除棉田杂草,饲养了数以万计的白鹅,把它们赶进棉田。白鹅拼命吃掉棉田杂草而不食一株棉苗,因为白鹅不喜欢棉株的味道,不会伤吃棉株。据实验,5只白鹅可以完成60亩棉田的除草任务。

Studies on the Community Structures of Meiofauna and Marine Nematode at Six Stations in the Southern Yellow Sea,China

Meiofauna (0.031-0.5 mm) were sampled and studied at a grid of six stationsduring the cruise of investigation for over winter ground of anchovy (Engraulis japonicus) in theSouthern Yellow Sea, China in January 2003. Total meiofauna individuals averaged (1.162 ± 0.347) x10^6 ind m^(-2) and the corresponding biomass 1.748 ± 0.72 g dwt m^(-2) with the maximum 2.35 g dwtm^(-2) at Station 9594 and the minimum 0.537 g dwt m^(-2) at Station 11794. A total of fourteentaxa were identified. Free living marine nematodes were the most dominant group with an averageabundance of (1.026 ± 0.206) x 10~6 ind m^(-2), accounting for 88.5% of total numbers, and anaverage of 85.4% lived in the surface layer (0-2cm) of sediments. The individual dry weight wascalculated, which ranges from 0.01 μg to 31.32 μg with an average of 0.261 μg. One hundred andforty two species or taxa of free-living marine nematodes belonging to 89 genera, 24 families and 4orders were identified. Six of them were new species. The common dominant species were Dorylaimopsisrabalaisi, Sphaerolaimus balticus, Sphaerolaimus mini-tus, Metalinhomoeus longicauda,Prochromadorella attenuata., Campylaimus sp. 1, Vasostoma sp. 1, Daptonema nor-mandicum,Paramonohystera riemanni, and Promonhystera sp. 1. According to cluster analysis of Primer 5.0, thesix stations were clustered into 2 groups with similar species composition at 40% similarity. Thespecies diversity index (H′), evenness index (J) and species richness index (d) of nematode werecalculated and analyzed. Correlation analysis with respect to environmental factors showed that theabundance of meiofauna had a significant correlation with the median diameter of sediment (Md_φ).The species richness of nematodes had a highly significant correlation with Chl-a and significantcorrelations with Pha-a and Chl-a + Pha-a.

Meiofauna Distribution in Intertidal Sandy Beaches Along China Shoreline(18?–40?N)

In this study,the distribution pattern of meiofauna from nine sandy beaches at six latitudinal gradients along Chinese coast between 18 and 40?N was studied on their meiofauna abundance to examine the effect of latitudinal gradients.In general,meiofauna abundance was lower in four subtropical beaches in Xiamen(24?N) and Zhoushan(29?N) than that in other beaches.Meiofauna abundance differed little between tropical and temperate beaches.The taxonomic structure of meiofauna showed a dominance of nematode in colder area.The relative composition of turbellarians and polychaetes increased in warmer area.In addition to latitudinal gradient,salinity,oxygenation,sediment grain size affect also the meiofauna latitudinal distribution.As for horizontal distribution,the highest meiofauna abundance was found in low tidal zone at tropical beaches,and in middle tidal zone at temperate beaches.The horizontal distribution of meiofauna was controlled by both physical and biotic factors including feeding and anthropogenic activities.Although meiofauna abundance exhibited a horizontal difference,the composition of meiofaunal main taxa was unanimous horizontally at all beaches at the same sampling latitude.

Effects of water depth and substrate color on the growth and body color of the red sea cucumber,Apostichopus japonicus

Three color variants of the sea cucumber,Apostichopus japonicus are recognized,the red one is highly valued in the market. When the red variant is cultured in ponds in China,its body color changes from red to celadon in 3–6 months. The effects of water depth and substrate color on the growth and body color of this animal were investigated. Juveniles of red A. japonicus were cultured in cages suspended at a range of water depths(20,50,100,150 and 200 cm). The specific growth rate of red sea cucumbers was significantly higher in animals cultured at deeper water layers compared with those grown at shallowers. Body weights were greatest for sea cucumbers cultured at a depth of 150 cm and their survival rates were highest at a depth of 200 cm. A scale to evaluate the color of red sea cucumbers(R value) was developed using a Pantone standard color card. All stocked animals in the 9-month trial retained a red color,however the red body color was much more intense in sea cucumbers cultured at shallower depths,while animals suspended in deeper layers became pale. In a separate trial,A. japonicus were cultured in suspended cages with seven different colored substrates. Substrate color had a significant effect on the growth and body-color of red A. japonicus. The yield were greatest for A. japonicus cultured on a yellow substrate,followed by green > white > orange > red > black and blue. All sea cucumbers in the 7-month trial retained a red color,although the red was most intense(highest R value) in animals cultured on a blue substrate and pale(lowest R value) for animals cultured on a green substrate.

Effects of Elevated Seawater pCO2 on Early Development of Scallop Argopecten irradias (Lamarck, 1819)

To investigate the effects of elevated seawater p CO_2 on the early developmental stages of marine benthic calcifying organisms, we exposed the eggs and larvae of Argopecten irradias, an important bivalve species in Chinese aquaculture, in seawater equilibrated with CO_2-enriched(1000 ppm) gas mixtures. We demonstrated that elevated seawater pCO_2 significantly interfered with fertilization and larval development and resulted in an increased aberration rate. Fertilization in the treatment(pH 7.6) was 74.3% ± 3.8%, which was 9.7% lower than that in the control(p H 8.3)(84.0% ±3.0%). Hatching success decreased by 23.7%, and aberration rate increased by 30.3% under acidic condition. Larvae in acidified seawater still developed a shell during the post-embryonic phase. However, the shell length and height in the treatment were smaller than those in the control. The development of embryos differed significantly at 12 h after fertilization between the two experimental groups. Embryos developed slower in acidified seawater. Nearly half of the embryos in the control developed into D-shaped larvae at 48 h after fertilization, which were considerably more than those in the treatment(11.7%). Results suggest that future ocean acidification(OA) would cause detrimental effects on the early development of A. irradias.

Effects of a Brine Discharge over Bottom Polychaeta Community Structure in Chabahar Bay

The brine discharge from desalination plants affects the benthic communities. Polychaetes are indicators to assess marine pollution. The aim of this study was to examine the effects of brine discharge over softbottom polychaete community in Chabahar Bay. Forty-two sediment samples were collected from seven stations in pre summer monsoon （April 2011） and post winter monsoon （October 2011） using Van Veen grab sampler. Changes in the polychaeta data assemblages were analyzed using univariate and multivariate techniques. Thirty-one polychaete species were identified with the highest abundance in station 6 in pre monsoon period and the lowest abundance in station 1 in pre monsoon. The results showed that the abundance, richness and diversity indices were decreased in the stations near the discharges area comparing to control stations far from the brine discharges zone. CCA （Canonical correspondence analysis） showed that salinity and temperature have influenced the community structure of polychaeta.

Sustainable Ecosystem Management versus Economic Exploitation： A Case Study of Lake Naivasha Basin, Kenya

Human activities in the Lake Naivasha catchments pose serious ecological threats to sustainable freshwater ecosystem management. The future hangs on the balance of economic exploitation and sustainable watershed conservation. Water abstraction volumes, embedded water/virtual water and chemical analysis of wastewater discharges were assessed. Dissolved oxygen, temperature, Secchi disc depth, benthic organisms＇ population and pesticides used in the farms were determined. The study found that abstraction exceeds safe water yield, farms have also encroached on the riparian lands and connected to the lake through canals allowing effluents to flow directly to the lake. Benthic community populations are low at points where discharge canals enter the lake, indicating inflow of materials are toxic. Canal samples show high contaminant levels of actions for sustainable exploitation of the resource is essential. compared to other sites. Wise use of the resource and implementation The determination of ecological and water footprints are recommend.

Relationship Population Density of Aquatic Sediment Macrozoobenthos to River Water Quality Parameters： Case Study of Upstream Citarum River in Bandung Regency

The increase in anthropogenic activities occur along the upstream of Citarum River Basin （CRB） in Bandung regency had a negative impact to the water quality caused by the presence of human activity, it will be able to be a disruption to the ecosystem aquatic. The purpose of this study was to determine the relationship of the physical and chemical parameters of water and sediment to the presence of macrozoobenthos populations. Based on the result of Pearson Correlation Analysis （PCA）, the parameters of COD, TOC and silt composition were the highest correlation to the macrozoobenthos population density, the value were 0.966, 0.865 and 0.576. Although PCA analysis is used to determine the relationship between the parameters of water, sediment and sediment particle distribution, the result showed that the water parameters were the mayor component affected the density of macrozoobenthos. While based on the composition of sediment, it is found that substrate as silt, clay and gravel and phosphate parameter affected the density of macrozoobenthos. The measurement of water quality also were calculated by Biotic Monitoring Working Party-Average Score Per Taxon （BMWP-ASPT） index showed that the quality were polluted condition, although by Pollution Index （IP） method showed as a light polluted category.

The Impact of Inoculum-Substrate Ratios on Microbial Levels during Psychrophilic Anaerobic Digestion

The study evaluated impact of psychrophilic anaerobic digestion on levels of viable populations of fecal indicator bacteria using various inoculum-to-substrate ratios （I：S）. Laboratory-scale batch reactors were maintained at 10 ℃ and 20 ℃ for 25 days with dairy manure substrate. Five treatments included inoculum （control inoculum; inoculum only [CI]）, manure （control manure; substrate only [CM]）, and 3I：1S, II：IS, and 1I：3S. E. coli decreased in all treatments, while Enterococci decreased in only a few treatments. Treatment 1 I： 1S achieved highest E. coli decrease at 20 ℃ （3.11 log）; CM showed highest E. coli decrease at 10 ℃ （2.33 log）. The 1I：3 Streatment showed highest decrease of Enterococci at 20 ℃ （1.82 log）, whereas CM had highest, but less substantial, decrease at 10 ℃ （0.49 log）. These decreases may be the result of environmental conditions, namely substrate limitation for E. coli, and, increased VFA （volatile fatty acid） levels for Enterococci. Lower I：S showed higher levels of indicator organisms; less stable conditions with more acidic pH, higher VFAs, and lower biogas production. Results suggest II：IS is ideal for starting a digester at 20 ℃, whereas 3I：1S appears optimal for 10 ℃, Overall, I：S influenced chemical parameters and fecal indicators during batch psychrophilic anaerobic digestion of manure.

Optimization on Pretreatment and Enzymatic Hydrolysis of Sugarcane Trash for Ethanol Production

The present study was conducted for the optimization of pretreatment and enzymatic hydrolysis of lignocellulosic biomass （sugarcane trash）, which is a renewable resource for the production of bioethanol. The pretreatment and enzymatic hydrolysis conditions including alkali （NaOH）/dilute acid （H2SO4）, substrate and chemical concentration for pretreatment, enzyme dosage, pH, temperature and substrate concentration for hydrolysis were varied and evaluated for sugar and ethanol production at the end. The optimum condition was accomplished using 15% w/v DS of 0-2 mm sugarcane trash in size of particle. It was pretreated with two steps of 2% w/v NaOH autoclaving followed by 2% w/v H2SO4 autoclaving with washing step after pretreatment. An enzymatic hydrolysis was then performed using 15% w/v DS pretreated substrate, hydrolyzed with cellulase 50 filter paper unit （FPU）/g DS at 50 ℃ and pH 5. After incubating at 160 r for 48 h, 117.16 g/L reducing sugar was obtained. The achieved sugar after enzymatic hydrolysis was finally fermented to ethanol by Saccharomyces cerevisiae TISTR 5596, with concentration of 48.17 g/L ethanol or yield 0.509 g/g reducing sugars which was equal to 99.81% of theoretical yield.

最后的礼物(短篇小说)

在我们这个光辉灿烂的时代,街区已经变得非常发达。它的范围异常广大,各种内部的公用功能复杂而具体,居住的人口多元而稠密,实际上现在的街区已经完全超越了过去一个完整城市的内涵。而此时。

水鸭子

近几年,欧美人发明了一种水中新玩艺儿,这种用高分子制成的器材,能使人任意畅行水中世界.人们形象地称之为“水鸭子”.水鸭子长约2米,重约1.6公斤,适用于任何河川及湖泊、海域,且配备简单,为手提式装置,船身与引擎可以在15秒内组合完毕,携带十分方便,适合全家休闲、度假使用.除水上娱乐外,还可适用于水底生物研究探勘、机动救援、拖拽(拖拽力约在180至225公斤之间).