By surveying the hydrology, water quality and phytoplankton assemblage of the Tangxi reservoir in 2003, characteristics of eutrophication and water quality management strategies, which related to watershed management and hydrodynamics, were preliminarily discussed.This reservoir had a high trophic state index (TSI), ranging from mesotrophic statue to eutrophic state, and varying temporally and spatially.TSI in flood season was higher than those in dry season, and was higher in the Xitou riverine zone than in the Xinqiao riverine zone.Microcystis aeruginosa, a species causing algal blooms, dominated in spring and early summer.Nutrients input into the upper water column were mainly from land runoff, due to high population and heavy pollution in the watershed.Consequently, treatment of domestic waste and reasonable fertilization in agriculture and increasing vegetation coverage in the catchment of the reservoir are necessary for lowing nutrients loading to the water body.As strong water column stability is crucial to the occurrence of cyanobacteria bloom in this reservoir, regulating the outflow and destratifying the water column vertically, which can cause water column well-mixing, are recommended as a hydrodynamic method to control cyanobacteria blooming.
Based on field investigation,the threatened coefficient,the genetic coefficient and the specific value coefficient were used for quantitative analyses to determine the priority of conservation of the national protected plants distributed in Xingdoushan Nature Preserve.The results showed that 7 species of the national protected plants belong to the first class protection,consisting 21% of total,16 species belong to the second,consisting 49% of total,7 species belong to the third, consisting 21% of total,and 3species belong to the fourth,consisting 9% of total.Some effective conversation measures have been provided.
In this paper, A lots of laboratory experiments using the acetylene inhibition method (AIM) were carried to investigate the N2O production processes in chernozem soil of meadow grassland in Inner Mongolia.The research results showed that the heterotrophic nitrification is the important microbiological process of N2O production in this kind soil.The potential of autotrophic nitrification and denitrification are different with the changing of grassland vegetation's growing periods.However, the sequence of their contribution is: heterotrophic nitrification > autotrophic nitrification > denitrification.The increasing and decreasing of N2O production potential result from the appearance of autotrophic nitrification in different growing period.Thereby, the N2O emission flux from temperate grassland soils was lower because that the heterotrophic nitrification is key N2O production process in these soils.
The size distribution of zooplankton was studied from April 2001 to December 2002, in a tropical reservoir, Liuxihe reservoir (South China).Within rotifers (50μm to 160μm ESD), biomass decreased slightly with size, while cladocerans (100μm to 512μm ESD) had a maximum biomass concentration per size class at medium ranges of body size.Copepods were the most important zooplankton fraction (contributed more than 60% of total zooplankton biomass), and covered all 10 size classes from 50 to 512μm in this study.The overall size distribution of zooplankton (50 to 512μm equivalent spherical diameter) showed an increase in biomass between successive size classes.
Phytoplankton community structure in the Guangzhou Sea was investigated from May 2003 to May 2004.The results show that there were 209 species in total, representing 89 genera.Among these, diatoms (122 species, representing 41 genera) accounted for 58.4%, and Skeletonema costatum was the most dominant species.The species richness and abundance of phytoplankton decreased from the inside of estuary to the outside of estuary, where there were high specie ruchness and density of phytopla -nkton due to the influences of dilution water.During the investigation, the annual average density of phytoplankton was 4.11×105cells·L-1, and shows double abundance peaks annually.
By determining the cell quantity, content of chlorophyll-a, astaxanthin content in Haematococcus pluvialis, the effects of three reactive oxygen species 1O2、H2O2 and ·OH on the growth and the accumulation of astaxanthin content were investigated,, preliminarily seek to the feasibility to enhance the astaxanthin biosynthesis by ROS.The results showed that 1) the content of asataxanthin in Haematococcus pluvialis was obviously increased by proper concentration of MB.When the concentration of MB was 10-7mol·L-1, content of asataxanthin could reach to 5.27μg·mL-1, much higher than the control.2) the growth of Haematococcus pluvialis was restrained by the ROS, but the restraining effect of MB was not so serious as H2O2 and reagent of ·OH.
The content of pollutant of several vegetables and their soil and the quality of irrigating water were analyzed,the major elements measured were Hg,As,Cd,Cr,Cu,Mn,Ni,Pb, Zn,Se and Sn which inhibit plant growth, destruct soil ecosystem after plant and soil absorbed and accumulated these heavy metals and even affect people health after eating these vegetables, while the content of POBx and phenol were measured.The result showed that agricultural irrigating water has been polluted.In the farmland which is irrigated long time by the sewage,the content of noxious matter of soil and plants were higher,some heavy metals have evidently surpassed limited standard,soil has reached the level of severity pollution,the agricultural ecological environment and farmland ecosystem were inferior estate,the farm produces will probably form potential imperilment to people.In respect of the relation of soil pollution and vegetables, it is first reported on the relation between seed of Momordica charantia and pollutant, it is also first reported on Brassica juncea,Vigna sesquipedalis absorbing Sn etc..The research result even showed that the capacity of absorbing and accumulating noxious substance by seed is the strongest,and root is stronger then stem and leaf.
Based on investigating on the mangrove resources in Zhanjiang in 2001 and 2005, we found that there was only 7242.0 hm2 of mangrove left.There are 24 plant species of mangrove in15 families in Zhanjiang.The area of mangrove in Zhanjiang had been decreased by 6363.6 hm2 during the period of 1980 to 2001.On the whole,the area of mangrove in Zhanjiang was decreased markedly, mainly resulted by the aquatic farming,and it had affected the development of local society and economy.There were lots of mangrove community types and plant species in Zhanjiang.Besides native species in the mangrove of Zhanjiang,Sonneratia apetala is a successful exotic species,which had adapted the local environment well.On the other hand,the survival rate of artificial mangrove in Zhanjiang is low.At the moment,to make sustainable use of mangrove of Zhanjiang,the priority must be to protect all the existing wetlands of mangrove in situ by setting up natural reserves and prevent anthropogenic destruction,and put forward the scientific program of rehabilitating and making good use of mangroves.Furthermore,enhancing the monitoring mangrove ecosystem resources and education of protection of mangrove are urgently needed.
171 water samples were collected from 56 stations in typical regions where Harmful Alage blooms frequently occurred in East China Sea during April to May,2004.Prorocentrum donghaiense cell density ranged from 2.5×103 to 6.0×107cells·L-1 at surface water layer, with an average of 4.87×106cells·L-1.At station rb12A located at 122.94°E and 30°N,The highest Prorocentrum donghaiense cell density was observed.Prorocentrum donghaiense cell density ranged from 1.0×103 to 5.32×106cells·L-1 at middle water layer, with average of 6.17×105cells·L-1.At stationrf 40 located at 122.53°E and 29.3335°N,the highest Prorocentrum donghaiense cell density was found.Horizontally, Prorocentrum donghaiense showed scattered distribution, while vertically,Prorocentrum donghaiense assembled on middle water layer before the outbreak of HABs, and upwells to surface layer after the high increased of cell density, caused the outbreak of HABs.
Environmental bacteria investigations were conducted in Litopenaeus vannamei low salinity intensive stocking ponds in the area of Pearl River Delta, Guangdong Province.The results showed that the mean of heterotrophic bacteria were 5.15×104cfu·mL-1 and pathogenic Vibrio were 5.00×103cfu·mL-1 in water column, but it were 2.41×106cfu·mL-1 and 1.45×105cfu·mL-1 in the ponds sediment, respectively.There was a less difference to heterotrophic bacteria whereas larger to pathogenic Vibrio in water and sediment in different ponds.In old shrimp ponds with a depth of sediment, the evenness of heterotrophic bacteria were 6.10×104cfu·mL-1 in water and 2.89×106cfu·mL-1 in sediment, and pathogenic Vibrio were 6.00×103cfu·mL-1 and 2.14×105cfu·mL-1, respectively.But in ponds of bottom renovated with little sediment, heterotrophic bacteria average were 4.53×104cfu·mL-1 in water and 2.08×106cfu·mL-1 in sediment, 4.34×103cfu·mL-1 of pathogenic Vibrio in water and 9.86×104cfu·mL-1 in sediment.The pathogenic Vibrio were higher obviously in sediment of old shrimp ponds, it would be the cause of diseases outbreak in old ones.Heterotrophic bacteria and pathogenic Vibrio was higher in early period of stocking, lower and stable in middle and final term in water column, but a fluctuation was found to them in the sediment throughout the low salinity stocking.High water temperature indicated an inhibiting to heterotrophic bacteria and pathogenic Vibrio in low salinity stocking ponds, moreover, the environmental bacteria were also impacted by phytoplankton.
The effects of MS-222, an anaesthetic for fish, on behaviors of Danio rerio were examined under laboratory condition.The results showed that the behavior of anaesthotized D.rerio was a gradual process, and four narcotic stages of fish behavior, non-anarcosis(Ⅰ), light anarcosis(Ⅱ), mediate anarcosis(Ⅲ), and deep anarcosis(Ⅳ), were defined in the present study.The time of the fish being in a certain narcotic stage was not familiar under different concentrations of MS-222.When exposing to high dosage of anaesthetic for 15min, fish in the water with MS-222 concentration of 80-90 mg·L-1 was in Ⅲ narcotic stage and all fish survived, but more than 90%of fish above 100 mg·L-1 of MS-222 finally died.In the experiment of conditional reflex of feeding, four treatments, photic stimulation but not anesthesia (P), neither photic stimulation nor anesthesia (NN), photic stimulation and anesthesia (PA), and not photic stimulation but anesthesia (A), were set.The time from putting the feed into the water to fish eating the feed in treatment P, NN, PA, and A was 12.06±1.34s, 13.20±1.13s, 56.56±56.48s and 36.20±25.74s, respectively.It was shown that MS-222 prolonged the time of conditional reflex.The present research could give an advice in using MS-222 in experiments and fish transportation.
The bioaccumulation and elimination under single low concentration of cadmium and low concentration of cadmium coexistence with humic acids in Asian clam (Corbicula fluminea) were investigated under laboratory conditions.The organisms were exposed to solution containing single low concentration of cadmium (1μg·L-1) and low concentration of cadmium (1μg·L-1) + humic acid(1mg·L-1 and 10mg·L-1).The exposure time lasted for 15 days.Samples were detected after 1d、2d、3d、10d、15d and showed that the bioaccumulation effects of both of the two treatments were linearly correlative with the increasing of the accumulation time.But it was found that cadmium bioaccumulation by the mussels decreased in the presence of humic acids.After 10ds and 20ds of elimination, Cd was difficult to be eliminated after the accumulation in the clams' body in both of the treatments.Humic acids had almost no effects on the elimination of low concentration of cadmium.
Highway has not only promoted the economic development of China, but also brought about prodigious convenience to our daily life.However, highway construction will produce problems such as soil erosion, water loss and destroying of the natural environment.The article analyses the soil erosion, water loss in the construction of Jieliang highway, and forecasts the new loss of the soil in the construction period.The America Universal Soil Loss Equation (USLE) is chosen to forecast the soil loss in construction area.Through calculation, it is anticipated that the new soil loss in construction period is 81.2×103t.According to the characteristics of the project, the construction region is plotted into several areas with corresponding prevention measures for each area.It is expected that 115.8×103t of soil loss can be controlled after the corresponding prevention measures have been implemented.
In this paper, based the monitoring data from May to December of 2003 in Guangzhou sea area, eutrophication in this area was assessed with a model refering to nutrient-limited characters,.Results showed that there was of a high nutrients concentration in Guangzhou sea area.The concentrations of DIN were higher than Sea water quality standard VI(GB 3097-1997).The concentrations of phosphate were between the Sea water quality standard of III and VI (GB 3097-1997) in spring and summer, while were higher than Sea water quality standard VI during rest of the year.Most of this area was at the stage of phosphorus-limited potential eutrophication or slightly-phosphorus-limited potential eutrophication.The concentrations of phosphate and DIN were increased annually in recent 20 years in Guangzhou sea area.
Droughts occurred in Xinyang City mainly fall into three categories: the midsummer drought, the autumn drought and the winter drought.And the frequency of midsummer drought is much higher than that of the other two.In addition to natural factors, such as monsoon circulation, landforms and underground water resources, droughts are also associated with some socially economic factors, including incompletion of irrigation equipments, irrationality of agricultural production structure and crop arrangement, enlargement of industrial production, and so forth.Based on the statistics, which are obtained by using Pa method in different degrees, of the drought's frequency and regularities of the drought's occurrence, this text puts forward feasible defense strategies, to be specific, including long-term defense strategies, short-term reaction techniques and after-drought temporary remedial measures.
Based on the investigation and analysis of water quality and water environment situation, the impacts of the project of expressway from Jiekou to Liangkou on water environment were analyzed and predicted.Especially the impacts on Liuxi River had been investigated in detail.By appraising, present quality of Liuxihe was good and met the demand of water environment function.The impact on water environment by the two large bridges in this project is important and was emphatically analyzed.Result shows that the impacted range is within 100m and 150 m downstream respectively.During operation period, negative impact on water-environment could be slight and lightened by adopting some environmental protection measures.
The coastal areas in China are experiencing rapid development, and the environment of coastal waters encountered huge impact.The traditional approaches of monitoring coastal water quality are not cost effiectively, and can not provide overall spatial information for certain coastal waters.Remote sensing is a novel approach to break these constraints.However, how to determine the monitoring parameters is a key to assess water quality by remote sensing.The situation of Daya Bay water environment was reviewed in this study, the optical or thermal actively characteristics of water quality parameters were also discussed, and it suggested that water temperature, suspended sediments and chlorophyll be the main parameters for assessing the water quality with the approach of remote sensing.Suspended sediments and chlorophyll can serve as surrogate contaminants which play an important role in remote sensing of water quality in inland lakes, rivers and coastal areas, chlorophyll was also proposed to be included in national water quality assessment system as a regular monitoring parameter.
The ecological footprint is a new method to estimate the level of natural resources utilization and the ecological carrying capacity of the nature.Its theoretical framework and calculation method are introduced in this paper.The ecological footprint ledger is composed of four main sections.The first is basic biotic resources consumption; the second is water resources consumption; the third is energy consumption; and the forth is trade balance.Based on the ecological footprint concept and analysis framework, the ecological footprint of Huizhou city in 2002 was calculated.The results show that the ecological footprint was 1.335hm2/cap; the ecological carrying capacity was 0.610 hm2/cap; the ecological deficit was 0.725hm2/cap; the ecological footprint diversity was 1.3808; the ecological footprint per 10000 yuan GDP was 0.719 hm2.There were some problems in sustainable development of Huizhou, because ecological footprint was much more than ecological carrying capacity.However, comparing Huizhou City with Guangdong Province and China, it was shown by footprint diversity, ecological carrying development capacity and the ecological footprint per 10000yuan GDP that the utilization mileage of natural capacity in Huizhou is higher and its development potential is stronger.
The importance of eco-ethics for wetland conservation and the methods of wetland conservation were discussed in this paper.The eco-ethics prompt the correct understandings of wetland value,enhance self-restriction and society supervise, provide the foundation for constitute and implement the law in wetland conservation.The eco-ethics require human being use wetland resource wisely, avoid unreasonable wetland development, and protect the endangered wildlife in wetlands.Within eco-ethics generations, the chance of utilizing wetland resource is regarded as equal for people in present when to satisfy their benefit.Wetland conservation is the common responsibility and obligation for all human being, between regions and countries.Between eco-ethics generations, people in present should develop and use wetland resource following the responsible, thrifty, careful principle, and avoid unbearable damage to the following generations.The methods of wetland conservation required by eco-ethics are as followed combining with the wetland science research, legislation on wetlands, society practice activity, propaganda and education.
In the course of aquaculture, drugs are broadly used in aquafeed because of the notable effects.However, because of drugs' residue、accumulation、movement and transformation in environment, the mass use of the drugs has brought a series of problems to ecological environment.This paper summarizes the different kinds of drugs' application in the aquafeed at present, as well as the ecological effects caused by the use of the drugs.This paper focuses on the following several respects: drug metabolism in the body of breed animals, fate of drugs in environment, the effects of drugs on aquatic organisms, drugs resistance of bacterium and final impacts on people.It clarified that the application of drugs in aquafeed has close relationship with the ecological environment and human's health, so research of its effects has important theoretical and practical significance.
In recent years, endocrine disrupters (EDs) aroused great attention in the research of environmental science.EDs is potentially harmful not only to the health of terricolous animals and humans, but also to the aquatic organisms by influencing their growth and reproduction after EDs enter the aquatic environment.It is thus necessary to establish some quick and sensitive methods for the detection and evaluation of EDs.The biological methods meet the request, and also reflect the toxic effects of chemical pollutants on organisms.In this paper, the in vitro and in vivo experimental methods for detecting and evaluating EDs were introduced; the biomarkers which were mainly obtained in fish and based on individual, histopathological, cellular, molecular and biochemical (proteins, enzymes, RNAs, hormones) levels were summarized.
The toxicity of chromium is related to its oxidation states, and the primary typical pollutant in chromium-containing electroplating waste water is hexavalent chromium.The recent advancement of the relevant study on hexavalent chromium pollution in electroplating waste water is reviewed.The main sources of hexavalent chromium in aquatic environment are analyzed.The research situation on the toxicity of hexavalent chromium on aquatic plants and animals is surveyed, including the accumulation and distribution of hexavalent chromium in organism after absorption and the induced morphologic, biochemical and ultrastructural damage.Some common kinds of treatment of hexavalent chromium contaminated electroplating waste water are introduced, emphasizing on the advantages of biological chromium reduction new technology and its perspective in the future.Finally the development trend of replacement of hexavalent chromium plating is presented.
