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汉丰湖富营养化综合评价与水环境容量分析 总被引：5，自引：0，他引：5
2012、2013年季节性监测了汉丰湖水体理化指标,采用综合营养状态指数法对其富营养化状态进行了评价,采用沃伦威德尔模型(Vollenweider)和狄龙模型(Dillon)计算了化学需氧量、总氮、总磷的水环境容量。结果表明:汉丰湖水质总体处于地表水Ⅱ类~Ⅳ类标准,TN 0.76~2.24 mg/L、平均1.41 mg/L,NH3-N 0.17~0.95 mg/L、平均0.41 mg/L,TP 0.010~0.106 mg/L、平均0.069 mg/L,CODMn2.34~14.60 mg/L、平均4.22 mg/L。东河区域水质优于小江干流、南河区域,秋季污染程度最轻;汉丰湖水体营养状态介于中营养到轻度富营养型,其中南河区域的营养程度相对较高;从单个评价因子看,总氮的营养状态最高,持续处于轻度、中度至重度富营养状态。汉丰湖化学需氧量、总氮、总磷水环境容量分别为37 335、109.1和1 643.84 t/a,为达到汉丰湖水功能区划Ⅱ类水的管理目标,总氮、总磷削减率分别为38%和56%。 相似文献
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为了解三峡水库库尾地区面源污染现状,以重庆市江津区笋溪河流域为研究对象,利用综合水质识别指数、内梅罗指数和主成分分析方法对笋溪河水质进行评价,主要评价指标有水温、pH、电导率、溶解氧、化学需氧量、总氮和总磷。结果表明:(1)笋溪河流域溶解氧为5.98～8.70 mg/L、化学需氧量为2～14 mg/L,总磷为0.008～0.105 mg/L,均处于Ⅰ类或Ⅱ类水质,总氮为0.64～2.03 mg/L,处于Ⅲ～Ⅴ类水质,污染严重。(2)3种水质评价方法均显示下游水质劣于上游水质,内梅罗指数在考虑平均超标水平的同时兼顾最大超标污染物,研究认为该指数的评价结果最能表现该地区的水质现状。(3)笋溪河上下游之间,溶解氧为上游显著高于下游,水温、pH、电导率、化学需氧量和总氮均为下游显著高于上游(P0.05),总磷浓度未发现有明显的差异(P0.05)。在后续管理中应提升城镇污水和农村污水的处理率,提高水肥利用率,以消减污染负荷、控制水污染趋势,从而改善区域水环境质量。 相似文献
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于2008-2009年对太湖贡湖水源地金墅港、田鸡港、龙塘港等3条主要河道的水质及大型水生植物进行了季节性野外调查,并对该区3月和6月的浮游植物进行调查。水质调查结果表明,贡湖水源地河流水体富营养化风险较大,主要污染指标为总氮和总磷,全年TN平均浓度为3.094mg/L,TP平均浓度为0.112mg/L。以叶绿素a、总氮、总磷、高锰酸盐指数和透明度为主,并结合浮游植物指标,利用综合营养状态指数法对不同季节水质营养状况进行评价,春季（3月）和夏季（6月）水源地均处于富营养化状态,其中春季达到中度富营养化[L 相似文献
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研究东圳水库水质变化趋势,计算工程实施后的污染物削减量,为水质保护提供依据。利用SMS模型基于二维不可压缩流体运动方程,建立东圳水库水域二维水流水质数学模型,采用有限单元法,模拟预测东圳水库水环境状况,主要水质分析指标为高锰酸盐指数、氨氮、总氮和总磷。预测结果表明,按目前污染物排放状况,2018年东圳水库水体中污染物含量为氨氮0.14~0.21 mg/L(II类水质)、COD 3.3~3.9 mg/L(III类水质)、总磷0.052~0.062 mg/L(IV类水质),总氮1.1~1.6 mg/L(IV类水质)。实施社会经济调控、污染源防治和生态保育工程后,2018年,预计东圳水库高锰酸盐指数、氨氮、总氮和总磷共排放1 616.6、163.7、1 182.4和155.5 t/a,分别削减了1 501.8、439.9、756.4和105.2 t/a;总氮0.4~0.8 mg/L、总磷0.022~0.032 mg/L,降幅均达到50%以上,达III类水质标准;COD 2.0~3.0 mg/L、氨氮0.11~0.18 mg/L,达到II类水质标准。提出的实施方案对保护东圳水库的水质具有建设性意义,水体水质目标可达。 相似文献
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淀山湖是黄浦江上游重要的饮用水源地保护区和生态涵养区。为评估淀山湖水生态健康状况,本文依据2013年、2016年、2019年和2022年的6月和9月生态调查资料,研究了淀山湖夏初、秋初浮游植物的种类组成、数量和多样性等群落结构特点。调查期间共检出浮游植物7门80属169种,其中绿藻门占绝对优势,其次为硅藻门、蓝藻门和裸藻门,甲藻门、隐藻门和金藻门种类数较少。在数量上以铜绿微囊藻（Microcystis aeruginosa）和尖尾蓝隐藻（Chroomonas acuta）的优势最明显,其中铜绿微囊藻是引起淀山湖水华的主要物种,且易在9月湖区的西南方引起蓝藻水华。6月和9月浮游植物密度变动范围分别为1.69～3.08×106 cells/L和1.31～128.67×106 cells/L,6月在湖区东北方的平均密度最高,9月在湖区西南方的平均密度最高。水华暴发年份（2016年和2019年）9月平均密度明显高于同年6月,水华未暴发年份（2013年和2022年）9月平均密度则低于同年6月。采用冗余分析（RDA）法研究浮游植物群落结构与环境因子的关系,结果显示水温、溶解氧、透明度、总磷、总氮和高锰酸盐指数等是主要环境影响因子,且水华暴发年份与水华未暴发年份水温、溶解氧、透明度、总磷和总氮等对浮游植物群落的影响存在一定差异;浮游植物群落主要受磷营养限制,其物种数量、密度及优势种主要受水温影响。采用不同指数法评价水质,发现Shannon-Wiener指数和Pielou指数对淀山湖蓝藻水华的指示比综合营养状态指数更灵敏。根据湖区出现的主要优势种均为富营养水体指示物种,以及生物多样性指数、均匀度指数和综合营养状态指数值,可以判断淀山湖夏秋季水体总体上处于轻-中度富营养化水平,且呈轻污染程度。 相似文献
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为掌握南水北调东线南四湖的水质现状，于2021年对4个湖区7个站位进行了周年调查，并采用单因子分析和综合营养状态指数法对水质状况进行了评价。结果表明：南四湖水体氨氮和亚硝氮浓度分别为0.166±0.015mg/L和0.050±0.009mg/L,总氮、总磷和CODMn浓度分别为1.767±0.191mg/L、0.053±0.005mg/L和10.58±0.46mg/L并分别超地表水III类水质标准76.69%、6.76%和76.41%;综合营养状态指数介于46.78～66.16,南四湖总体为轻度富营养状态，但部分水域仍存在较重的富营养化问题。伴随南水北调东线的常态化调水及多种水质涵养措施的实施，南四湖水体的富营养状况有所转好，但在部分季节的部分区域仍存在富营养化风险。 相似文献
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2016年7月至2017年5月对乌伦古湖12个采样点(4个湖区)的水质进行了监测,分析了不同湖区的水质特征,并对比历史资料探究水质变化及成因。结果显示,乌伦古湖2016-2017年度年均矿化度为1.64 g/L、p H为8.70、透明度为1.90 m、水深为8.78 m、溶解氧为7.55 mg/L,总氮1.06 mg/L,总磷0.03 mg/L。与2006-2008年相比,年均矿化度由2.31 g/L降低到1.64 g/L,各湖区矿化度含量均降低,其中靠近额尔齐斯河引水的小海子(由1.97 g/L降至0.82 g/L)和接受吉力湖来水的中海子(由2.41 g/L降至1.60 g/L)矿化度降低最为明显;年均总氮含量由0.86 mg/L增加到1.06 mg/L,年均总磷含量稳定在0.03 mg/L左右,各湖区总氮、总磷含量除小海子降低外(总氮由0.83 mg/L降至0.72 mg/L;总磷由0.03 mg/L降至0.01 mg/L),其他各湖区含量保持稳定或升高,其中中海子升高最为明显(总氮由0.94 mg/L升至1.43 mg/L;总磷由0.03 mg/L升至0.05 mg/L)。研究表明,额尔齐斯河引水对于乌伦古湖水体矿化度、总氮及总磷均有稀释作用,吉力湖来水虽然对乌伦古湖水体矿化度也有稀释作用,但同时提高了总氮和总磷含量。 相似文献
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典型湖泊边缘区丰水期营养状态及其影响因子研究—以蚌湖为例 总被引：1，自引：0，他引：1
为探讨影响典型湖泊边缘区藻类生长的主要水质因子,于2011年7月测定了蚌湖的叶绿素a含量,并对其分布特征及相关性进行分析。结果表明,叶绿素a(Chl.a)浓度的变化范围为0.55～1.56mg/m3,表现出一定的空间差异性,以入湖口处和湖尾区最大。总氮(TN)为0.699～2.596mg/L,以湖尾区最高;总磷(TP)浓度整体较低,最大值仅为0.0318mg/L;N/P浓度比均大于30,表明蚌湖为磷限制性湖泊。根据修正的卡尔森营养状态指数,丰水期蚌湖均处于贫-中营养水平,其中湖尾区条件最适宜藻类繁殖。由相关性分析结果可知,TN、TP、pH、COD和NO-3-N为藻类生长的主要影响因子;其中,Chl.a含量与COD呈显著正相关,一定浓度范围内的COD增长会促进藻类生长繁殖;不同于国内大多数淡水湖泊,Chl.a含量与pH值呈显著负相关,主要原因是蚌湖水体碱度较高,大部分区域pH值超过了藻类生长的最适范围。 相似文献
11.
Liping Li Rui Wang Wanwen Liang Xi Gan Ting Huang Yan Huang Jian Li Yunliang Shi Honglin Luo Ming Chen 《广西水产科技》2014,(1)
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China. 相似文献
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Growth hormone (GH) and reproduction: a review 总被引：5，自引：0，他引：5
Florence Le Gac Odile Blaise Alex Fostier Pierre-Yves Le Bail Maurice Loir Brigitte Mourot Claudine Weil 《Fish physiology and biochemistry》1993,11(1-6):219-232
Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations. 相似文献
14.
Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation. 相似文献
15.
Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection 
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下载免费PDF全文 G Sharon M Pimenta‐Leibowitz M C L Vilchis N Isakov D Zilberg 《Journal of fish diseases》2015,38(1):67-74
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality). 相似文献
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The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I–1 total alkalinity; 22 total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169moles·kg–1 fish·h–1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.Urea was present at high concentrations in all tissues and plasma (25 – 35moles·g–1·ml–1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min–1·g–1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min–1·g–1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated. 相似文献
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There has been growing concern about the overuse of antibiotics in the ornamental fish industry and its possible effect on the increasing drug resistance in both commensal and pathogenic organisms in these fish. The aim of this study was to carry out an assessment of the diversity of bacteria, including pathogens, in ornamental fish species imported into North America and to assess their antibiotic resistance. Kidney samples were collected from 32 freshwater ornamental fish of various species, which arrived to an importing facility in Portland, Oregon from Colombia, Singapore and Florida. Sixty‐four unique bacterial colonies were isolated and identified by PCR using bacterial 16S primers and DNA sequencing. Multiple isolates were identified as bacteria with potential to cause disease in both fish and humans. The antibiotic resistance profile of each isolate was performed for nine different antibiotics. Among them, cefotaxime (16% resistance among isolates) was the antibiotic associated with more activity, while the least active was tetracycline (77% resistant). Knowing information about the diversity of bacteria in imported ornamental fish, as well as the resistance profiles for the bacteria will be useful in more effectively treating clinical infected fish, and also potential zoonoses in the future. 相似文献
18.
Effect of iodophor disinfection of non‐hardened Salmo trutta eggs on their bacterial and fungus load 下载免费PDF全文
下载免费PDF全文 Franz Lahnsteiner 《Aquaculture Research》2017,48(7):3901-3909
This study investigated the efficiency of iodophor disinfection (135 ppm active iodine for 15–30 min) of non‐hardened Salmo trutta eggs against different groups of bacteria and against fungus. Egg samples were taken from non‐disinfected and from disinfected eggs, microorganisms were cultured on specific nutrient media and their mass was measured by turbidimetric methods. Bacteria and fungus mass of non‐hardened eggs could be reduced but not eliminated by iodophor disinfection with 135 ppm active iodine for 15 min. The extent of reduction was 47–65% (Experiment 1). The efficiency of disinfection increased with disinfection time as the reduction in bacteria and fungus mass was 40–55% after 15 min and 58–74% after 30 min (Experiment 2). Disinfection efficiency of iodophor solution diluted in water (reduction 49–57%) and of iodophor solution diluted in sodium chloride solution iso‐osmolar to the oocytes (reduction 52–61%) was similar (Experiment 3). The reduction in bacteria and fungus mass was persistent as it was 39–72% lower in embryos deriving from disinfected eggs than in embryos deriving from non‐disinfected ones (Experiment 4). In conclusion, the tested disinfection method is inadequate to eliminate pathogens completely but it could positively influence immune defence of eggs and embryos. 相似文献
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T. Citarasu K. Venkatramalingam M. Micheal Babu R. Raja Jeya Sekar M. Petermarian 《Aquaculture International》2003,11(6):581-595
The indiscriminate use of antibiotics and chemicals in shrimp hatcheries has led to biomagnification and that in turn could
lead to rejection of a whole consignment. The application of the bioencapsulation technique as a tool for curative treatment
in shrimp larvae was investigated. Herbs having antibacterial properties such as Solanum trilobatum, Andrographis paniculata and Psoralea corylifolia (methanolic extracts) were bioencapsulated in Artemia and fed to Penaeus monodon post larvae PL 1–25. The post larvae were reared in a medium inoculated with pathogenic bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Vibrio sp. Post larvae reared in the non-inoculated water and fed with non-enriched Artemia exhibited 90% survival, highest specific growth rate (12.43%) and reduced bacterial load. P. monodon reared in the bacterial inoculated water and fed with the non-enriched Artemia exhibited the lowest survival (10–30%), specific growth rate (8.42–9.1%) and increased bacterial load (2.86 × 103 to 3.76 × 105 cfu/g). The methanolic extracts of the herbs helped to increase survival and specific growth rate and reduced bacterial load
in the P. monodon culture system. Among the three herbal extracts, P. corylifolia enriched Artemia fed post larvae showed the tendency to higher survival (>50%), growth rate (11.5 averaged) and low bacterial load (1.12 × 105 cfu/g).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献