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1.
中华绒螯蟹有机和常规养殖池塘底泥氮磷溶出特性研究   总被引:1,自引:1,他引:0  
采用室内模拟研究的方法,研究中华绒螯蟹(Eriocheir sinensis)有机和常规养殖底泥中氮、磷的溶出规律。结果显示:有机组氨态氮溶出总量明显高于常规组,覆水前期,底泥厚度是决定氨态氮溶出总量的主要因子,中后期底泥类型成为主要因素。相同厚度底泥中有机组硝态氮的污染负荷明显低于常规组。常规组较有机组更容易在短时间内溶出硝态氮和亚硝态氮。5 cm和10 cm底泥厚度下有机组溶出总磷量分别高于常规组60.5%和56.5%,但在前4 d有机组的溶出速率低于常规组,应提早换水以有效控制总磷浓度。  相似文献   

2.
固定化微生物修复养殖池塘污染底泥的围隔试验   总被引:4,自引:0,他引:4       下载免费PDF全文
摘要:通过测定上覆水的多项水质指标、底泥总有机碳(TOC)、底泥生物降解能力(G值)、底泥异养细菌数和反硫化细菌数等指标值,在野外实验围隔条件下比较了固定化微生物和游离微生物(FR-M)对污染底质的生物修复能力。微生物固定所用载体包括:纤维网状活性炭,生物活性炭,沸石和硅藻土(相应的固定化微生物分别标记为FC-M、 BC-M、ZE-M和DI-M组)。结果显示:固定化微生物对围隔内水质有间接影响,试验后期固定化微生物组(ZE-M、DI-M和FC-M组)的上覆水硝氮浓度显著高于对照组;BC-M组和ZE-M组上覆水中的COD值显著低于游离微生物组(FR-M)和对照组,说明固定化微生物有效削减了水底界面还原性物质的污染程度;与游离微生物或对照组相比,固定化微生物组(FC-M组、DI-M 组和ZE-M组)能更有效地降解底泥有机质。固定化微生物对底泥生物降解能力(G值)的影响明显,实验后期固定化微生物组((BC-M组、DI-M组和ZE-M组)的G值均显著高于对照组和游离微生物组,说明固定化微生物技术的运用显著提高了围隔底泥的生物降解能力;固定化微生物对围隔内底泥异养细菌总数影响不显著,可能是由于底泥微生物群落结构受其它多种因子的综合影响所致。固定化微生物对底泥反硫化细菌影响显著,与对照组和游离微生物组相比,固定化微生物(尤其是ZE-M和BC-M组)能更有效地减少围隔底泥反硫化细菌数。本实验结果显示,利用载体固定微生物技术能显著提高微生物对污染底质的生物修复能力,其中以ZE-M和BC-M组效果最好。  相似文献   

3.
在仿刺参夏眠前后(6-10月),原位采集仿刺参养殖池塘的沉积物一水界面样品,检测沉积物上覆水的氨氮、亚硝态氮、硝态氮和无机磷酸盐含量及变化,研究沉积物一水界面氮、磷通量变化规律。试验结果显示,亚硝态氮+硝态氮(NO_x~--N)通量呈先降后升的变化规律,8月的NO_x~--N通量达到极低值,为-(66.12±7.66) mg/(m~2·d);氨氮(NH_4~+-N)通量呈先升后降再升高的变化规律,7月的NH_4~+-N通量达到最高值,为(6.21±0.55) mg/(m~2·d),9月达到极低值,为-(14.88±1.44) mg/(m~2·d);可溶性无机磷酸盐通量呈先升后降的变化规律,8月的可溶性无机磷酸盐通量达到最高值,为(4.20±0.56) mg(m~2·d),10月达到极低值,为-(3.48±0.43) mg/(m~2·d)。相关性分析发现,可溶性无机磷酸盐通量与水温呈显著的正相关,与水体中可溶性无机磷酸盐含量呈显著负相关;NO_x~--N通量与水体中亚硝态氮和硝态氮含量呈显著正相关。试验结果表明,仿刺参夏眠期间池塘沉积物是重要的氮汇和磷源,对水体的氮磷含量起着重要的调节作用。  相似文献   

4.
《淡水渔业》2021,51(3)
为了解曝气联合投加菌藻对湖泊水体的生态效应,于2019年7月24日-10月16日,在白洋淀沟壕中开展了曝气联合投加菌藻的水体生态修复试验,对比分析了修复水体和未修复水体的理化指标及浮游甲壳动物群落结构。结果显示:试验期内,曝气联合投加菌藻修复技术对水体总氮(TN)、总磷(TP)浓度的影响并不明显,但能显著降低水体亚硝态氮(NO~-_2-N)浓度,同时明显减少了上下水层的溶解氧差异,对打破水体上下分层具有明显效果;进行生态修复的水体中,浮游甲壳动物优势种逐渐由枝角类的短尾秀体溞(Diaphanosoma brachyurum)、长肢秀体溞(Diaphanosoma leuchtenbergianum)向桡足类的温剑水蚤(Thermocyclops sp.)、桡足幼体(Copepodid)和无节幼体(Copepod nauplii)转变,浮游甲壳动物种类组成趋于小型化;生态修复区内浮游甲壳动物生物量和密度有明显降低的趋势。综合结果来看,曝气联合投加菌藻修复技术能显著降低湖泊水体的亚硝态氮浓度,打破水体上下分层状态,同时使浮游甲壳动物生物量和密度明显降低,使其物种趋于小型化。  相似文献   

5.
为了提高海水循环养殖系统(RAS)中曝气生物滤器(BAF)系统脱氮效率,减少亚硝态氮(NO2–-N)积累和曝气量,将铁基复合生物填料引入BAF系统,以间歇式曝气营造BAF系统好氧、缺氧和厌氧的循环环境,采用扫描电子显微镜考察了填料表面形态,研究了不同复合填料配比及曝气运行方式下的氮污染物的处理效果,并利用单因素实验对生物滤器的各重要运行参数进行优化。结果显示,添加铁基填料可以提高约10%的脱氮效率,降低25%的NO2–-N积累并节省50%的曝气量;海水BAF系统在如下运行参数条件下有更优的去除性能,间歇曝气时长为12 h,聚碳酸亚丙酯(PPC)凝胶亲水填料与海绵铁复合配比为3∶1,温度为30℃,水力负荷率(HLR)为1.2 m3/(m2·d),进水氨氮(NH4+-N)负荷为1 mg/L。研究表明,在RAS中引入铁基填料并以间歇曝气方式运行,能提高BAF系统处理氮污染物效率,明显降低NO2–-N积累和运行耗电量,为BAF在RAS中的生产应用提供理论依据。  相似文献   

6.
《淡水渔业》2021,51(3)
为了研究生态基对大口黑鲈(Micropterus salmoides)养殖池塘氮,磷累积的影响,对大口黑鲈进行了6个月的室外池塘养殖试验。养殖期间不同时间段内分别对养殖水体亚硝态氮(NO_2-N)、硝态氮(NO_3-N)、铵态氮(NH~+_4-N)、磷酸盐(PO_4~(3-)-P)、总氮(TN)、总磷(TP)、总有机碳(TOC)含量以及养殖池塘底泥的TN、 TP、TOC含量进行了测定。结果显示:养殖水体氮相关指标中,生态基处理组TN、NO~-_3-N、NH~+_4-N含量极显著低于对照组,N累积显著低于对照组;生态基处理组TP含量极显著低于对照组,水体P累积显著低于对照组。池塘底泥中碳、氮、磷相关指标中,生态基处理组池塘底泥TOC、TN、TP含量与对照组无显著差异。实验结果表明,挂设生态基对降低大口黑鲈养殖池塘水体氮、磷含量有显著效果。  相似文献   

7.
该文采用生态学试验方法,对鳜池塘和大棚养殖模式的水质变化规律进行了调查分析,同时采用不同微生态制剂商品(光合细菌、枯草芽孢杆菌、乳酸菌)对鳜养殖水体水质调节效果进行了研究。结果显示,整个鳜养殖周期(苗种至商品鱼),大棚养殖模式水体温度、溶氧、pH值与池塘养殖模式无明显区别;大棚养殖模式三氮(铵态氮、硝态氮、亚硝态氮)变化规律与池塘养殖模式大致相同,但大部分时间前者水体含量较高;大棚养殖模式水体总磷含量高于池塘养殖模式,且总磷最高值出现时间较池塘养殖模式推迟了近1个月。光合细菌对鳜养殖水体氨氮、亚硝态氮以及总氮整体调控效果最佳;枯草芽孢杆菌对降低硝态氮和亚硝态氮有良好的效果;乳酸菌对养殖后期降低水体pH值有一定的作用。结论:相对于鳜池塘养殖模式,大棚养殖模式氮磷物质循环转化效率较低,合理搭配使用微生物制剂调节水质养殖效果更佳,同时需注意不良天气对微生态制剂使用效果的影响。  相似文献   

8.
采用UPLC-MS/MS法,研究了阿维菌素泼洒用药后,该药物在水体、底泥、伊乐藻(Elodea nuttallii)和水产动物体内的蓄积与消除规律。结果显示,以6μg/L浓度单次泼洒用药后,水体中阿维菌素消解较快,其半衰期为63.8h。阿维菌素在养殖水环境中消减的同时,逐渐由水体向底泥、伊乐藻和水产动物迁移。底泥中阿维菌素峰浓度、曲线下面积和半衰期分别为1.25μg/kg、469.2μg/(kg·h)和115.5 h,说明伊乐藻中的相应值分别为8.75μg/kg、2521.7μg/(kg·h)和315.0h,说明伊乐藻对阿维菌素有明显的吸收和富集作用。该模拟系统中的异育银鲫(Carassius auratus gibelio)对阿维菌素具有明显的吸收,其血液、肾、鳃、肝和肌肉组织阿维菌素的最高浓度(C_(max))依次为50.9、45.37、21.25、15.47和11.9μg/kg;而该模拟系统中的中华绒鳌蟹(Eriocheir sinensis)仅鳃组织检出阿维菌素,其C_(max)在12h为8.08μg/kg,血淋巴、肌肉和肝胰腺等组织均未检出阿维菌素。生物富集系数F_(BC)值显示,对阿维菌素的富集浓度由高到低依次为鲫鱼、伊乐藻、中华绒鳌蟹、底泥,显示阿维菌素在不同分配相和不同生物组织的富集作用差异较大。  相似文献   

9.
微生物促生剂在沉积物修复中的作用机理及应用现状   总被引:1,自引:0,他引:1  
水生态系统中沉积物是各类污染物质的汇集库,在外源污染陆续得到有效控制的基础上,亟需对内源污染特别是沉积物污染进行有效去除。在沉积物修复方法中,微生物促生剂技术由于具有安全环保、持续时间长、成本低等优点而受到重视。综述了微生物促生剂的概念及其修复沉积物的作用机理,主要是通过增加沉积物中环境污染物的生物利用性使其可被生物降解,调整土著微生物的群落组成使其向有利于降解污染物的方向发展;并归纳了微生物促生剂的应用现状,除直接投加微生物促生剂外,还包括微生物促生剂配方研制、微生物促生剂缓释技术研发、微生物促生剂与其他方法的联合使用等,梳理了微生物促生剂应用优势和存在的问题,对微生物促生剂在沉积物修复领域的发展趋势进行了展望。  相似文献   

10.
为了探究上覆水类型及流速对养殖池塘底泥耗氧速率(SOD)的影响,在实验室进行6组水池平行实验,实验期为2 d,采用6个装置相同的玻璃缸进行对照实验,分别选取自来水和池塘原水作为上覆水体,在实验过程中利用水泵对上覆水进行循环流动,调节水泵循环流量以得到不同的上覆水流速,并采用2台溶氧仪测定不同实验条件下的上覆水水温和DO浓度,记录每次测量的对应时间点,测量间隔约为30 min。结果表明,当上覆水体为自来水和池塘原水时,在不同的循环流速下,SOD的范围为0.042~0.426 g/(m~2·d)。实验第2天各水池的SOD值较第1天均有一定下降,说明SOD随着水体中DO降低也相应减小,表明SOD与DO浓度有显著相关性。当上覆水处于静止状态时,其类型对SOD值有较大的影响,池塘原水在第1天和第2天的SOD值分别为0.426 g/(m~2·d)和0.297 g/(m~2·d),而自来水在第1天和第2天的SOD值均为0.258 g/(m~2·d),与上覆水体为自来水相比,有机物质含量高的池塘原水在第1天和第2天的SOD值分别高出65.12%和15.12%;当上覆水处于流动状态时,池塘原水的SOD为0.042~0.237 g/(m~2·d),自来水的SOD为0.045~0.252 g/(m~2·d),增幅仅为5.9%~15.0%,表明在此条件下上覆水体类型对实验水池的SOD值影响不显著。SOD与上覆水流速存在一定的相关性,对应最小的SOD值有一个流速较低值。  相似文献   

11.
The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.  相似文献   

12.
13.
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   

14.
Growth hormone (GH) and reproduction: a review   总被引:5,自引:0,他引:5  
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   

15.
In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.  相似文献   

16.
Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg?1 protein) than essential amino acids (425.82 ± 9.15 g kg?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting.  相似文献   

17.
18.
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   

19.
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   

20.
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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