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1.
高坝导致的河流气体过饱和及其对鱼类的影响   总被引:7,自引:0,他引:7  
高坝泄洪是导致水中气体过饱和的主要因素,不仅能致鱼类气泡病,而且会给水生生物带来严重的危害。本文主要就气体过饱和及气泡病做了具体描述,首先叙述了气体过饱和的研究概况、导致气体过饱和的原因和水温、压强等影响气体过饱和的因素,具体分析了鱼类不同生活阶段、液静压、温度、间歇性的暴露、探知和躲避能力导致其对气体过饱和忍耐大小的状况,并对气泡病的内部损伤如血液中形成的气栓、外部症状如身体各个部位形成的气泡做了具体的描述。  相似文献   

2.
针对向家坝库区溶解性气体过饱和对鱼类的影响,开展溶解性气体过饱和自然水域中胭脂鱼( Myxocyprinus asiaticus)的血气酸碱平衡的分析研究。结果表明,中度染毒组血液(暴露于溶解气体饱和水体2 h)碳酸氢根浓度(AB)、标准碳酸氢盐浓度(SB)、二氧化碳含量(TCO2)水平显著下降,全血碱超(BEb)、细胞外液碱超(BEecf)负值显著增加, pH、氧分压( pO2)、二氧化碳分压( pCO2)、血氧饱和度( SO2)均下降,半饱和度氧分压( p50)显著升高;重度染毒组(暴露于溶解气体饱和水体4 h) AB、 SB、 TCO2、 pH、 SO2均显著下降, BEb、 BEecf负值均显著增加, pO2、 pCO2均升高, p50显著升高;溶解气体过饱和水体引起胭脂鱼发生酸中毒。  相似文献   

3.
为探讨总溶解气体(total dissolved gas,TDG)过饱和对达氏鲟(Acipenser dabryanus)耐受性的影响,选取达氏鲟幼鱼为研究对象,开展不同浓度的TDG过饱和水体急性暴露室内实验。结果表明:达氏鲟受TDG过饱和水体胁迫后,生理异常现象和气泡病症状较明显,表现出对TDG过饱和水体的低耐受性。在饱和度为125%、130%、135%和140%的TDG过饱和水体浓度下半致死时间分别为4.4、2.54、2.36和2.23 h,达氏鲟死亡率随暴露时间和TDG饱和度的增加而增加。  相似文献   

4.
三峡工程运行后长江中游溶解气体过饱和演变研究   总被引:3,自引:0,他引:3  
为了分析三峡工程运行后泄洪对长江中游溶解气体过饱和的影响,本文建立了长江中游溶解氧数学模型,对不同流量下长江中游的溶解氧过饱和演变进行了模拟预测。模拟结果表明,三峡和葛洲坝过坝水流的溶解氧饱和度在40000m3/s~50000m3/s和100000m3/s附近存在两个峰值,长江中游河道天然情况下溶解氧过饱和恢复速度较为缓慢,平均每100km降低5%,洞庭湖水的汇入能显著降低长江干流的溶解氧过饱和度。当三峡出库流量超过40000 m3/s时,其影响范围可达400km以上。本文讨论了溶解气体过饱和的不同指标间的关系,对气体过饱和可能造成的影响以及对长江中游鱼类目前的影响进行了阐述,认为通过三峡水库的调度减小出库高流量次数和历时是减缓下游溶解气体过饱和的有效手段。  相似文献   

5.
为解析总溶解气体(TDG)过饱和导致鱼类发病的机理,本研究以长江上游特有土著鱼类中华倒刺鲃(Spin-ibarbus sinensis)为实验对象,通过将其暴露在4个不同浓度TDG过饱和水中,测定其酸碱度(pH)、二氧化碳分压(pCO2)、碳酸氢根(HCO3-)、总二氧化碳(TCO2)、葡萄糖(Glu)、红细胞压积(H...  相似文献   

6.
水生生物的一个重要特点是能够经由体表吸收水中的溶解物质。许多资料表明,鱼类能从周围水体中吸收某些营养元素而使之维持平衡。毒物、药物及其它物质也能由水中渗入鱼体。计算鱼体的物质平衡,重要的是了解鱼类对水中溶解物质的吸收率,即水中所含物质有多大比例渗入鱼体。  相似文献   

7.
一、病因气泡病通常多发生在鱼苗、鱼种阶段。在有些情况下,也能在成鱼中发生。其发病类型常见的有两种。一种是在鱼苗的肠道内出现气泡,使鱼体比重减轻,以致法下沉;或在鱼体表、鳍组织内以及鳃丝上附着许多小气,使鱼体上浮,游泳失常。另一种情况是在血循环系统中现气泡,直接影响血液循环和呼吸。这种病发生的原因,是由于水中溶解气体的总量过饱和某种气体过饱和,因而出现游离状态的气体,引起此病。些过饱和的气体来源有下面几种情况:1.由于鱼苗塘投施过多未经发酵的肥料,这些肥料沉池底,在缺氧的情况下分解,而释放出甲烷、…  相似文献   

8.
近年来,在初春季节章丘市的成鱼塘中频频发生气泡病,重病塘鱼类死亡率达到20%,危害较大。现将该病的发生情况及采取的防治措施报告如下,供同行参考。一、发病情况1郾池塘条件:气泡病在本市多发于淤泥较厚的精养高产塘。发病期间池塘水深0.6~1米,池水透明度30厘米左右。水源为地下水和引黄水,符合渔业用水水质标准。2郾流行情况:流行季节为3~4月份,3月中旬~4月上旬、水温6~10℃时为发病高峰期,秋末冬初偶有发病。从鱼种到成鱼均可感染此病,草鱼鱼种和成鱼受危害最大,同池的鲢鳙鱼、鲤鱼次之,重病池鱼类发病率达到80%,治疗不及时病鱼死亡率可…  相似文献   

9.
为探究紊动对水体中溶氧释放的促进效果,设计以潜水泵排水的方式,开展了不同水泵数量、功率、摆放方式、排水方向等工况下过饱和溶氧释放过程研究试验。结果表明,紊动对水体中溶氧释放有较好的促进效果。放入5个泵(功率20 W、纵向排水)时,水体溶氧释放系数为0.514 h~(-1),是未放入水泵时溶氧释放系数0.026 h~(-1)的19.77倍。当水泵垂直于水面排水时,溶氧释放效果较好。水泵个数越多、功率越大,溶氧释放系数越大,溶氧释放效果越好。  相似文献   

10.
通过气体过饱和发生装置来模拟高坝泄洪时产生的气体过饱和水体,设置气体饱和度分别为100%、110%、120%、130%、140%的水体,探明其对草鱼(Ctenopharyngodon idella)和鲢(Hypophthalmichthys molitrix)不同早期发育时期(受精卵、仔鱼、幼鱼)的影响,揭示了实验鱼在气体过饱和水中暴露时间和死亡率变化的关系,并计算了幼鱼在不同过饱和度的半致死时间。结果显示:各气体饱和度水体对实验鱼受精卵的发育和孵化均无显著影响;气体过饱和会导致实验仔鱼腹部肿胀充气,幼鱼各个组织均产生气泡;实验幼鱼对气体过饱和的耐受力低于仔鱼;气体饱和度越高对实验鱼的致死效应越强;草鱼仔幼鱼对气体过饱和的耐受力低于鲢。  相似文献   

11.
    
Total dissolved gas (TDG) supersaturation generated in the river may result in gas bubble disease to Chinese sucker (Myxocyprinus asiaticus Bleeker) and cause their mortality. To assess the effects of TDG supersaturation on Chinese suckers in laboratory, juvenile fish were exposed to different levels of TDG supersaturated water. All of the fish died when the TDG saturation reached and exceeded 125%, but none died at TDG of 120% saturation in 96 h. To evaluate the effects of intermittent exposure of TDG supersaturation, Chinese suckers were exposed to TDG of 130% for a specific duration and then provided a recovery period at 100% saturation. The results showed that some remission is possible for intermittent exposure. Because of the characteristics of natural rivers, experiments exploring the TDG supersaturation detection and avoidance abilities of Chinese suckers were conducted and demonstrated the fish can avoid TDG supersaturation in both the horizontal and vertical directions when higher TDG levels were available. The results indicate the tolerance threshold of juvenile Chinese suckers is a TDG level of 120% saturation.  相似文献   

12.
本文首次对鲟鱼气泡病作了报道,文章对该病病症进行了描述。初步分析了鲟鱼气泡病病因,并提出了防治鲟鱼气泡病的几点意见。  相似文献   

13.
    
ABSTRACT:   A microscopic bubble generating system (MBGS) has been developed to control dissolved oxygen (DO) levels suitable for fish farming. The MBGS has been tested to confirm its capability in net pens. Water conditions in a fish farm were monitored every two hours from June to October 2004 by setting an online vertical profiling system (OVPS) close to the net pen. DO in the net pen water decreased to physiologically stressful levels for the fish during the night (4.84–5.51 mg/L), while the DO was kept in saturated conditions during the day, due to oxygen supply from phytoplankton. The MBGS was operated from the evening to the morning of the next day for 16 h, to successfully create DO-saturated conditions in the net pen water at night. By using microscopic bubbles during the warm seasons, DO levels in the net pen water could be improved to a level suitable for fish farming. However, the low DO levels (<5.0 mg/L) of the bottom water occasionally extended to the net pen layers, despite the supply of microscopic bubbles to the water. To maintain the DO of the net pen water at levels suitable for fish farming, DO supply to the net pen water and the bottom water needs to be increased, and the organically enriched sediment just below the net pens needs to be treated.  相似文献   

14.
    
Flood discharge containing excessive suspended sediments (SS) can result in total dissolved gas (TDG) supersaturation downstream of dams. It has been confirmed that high TDG levels and excessive SS cause serious threats to fish survival. To explore the effects of TDG supersaturation on the hatchability of Chinese sucker (Myxocyprinus asiaticus Bleeker) eggs, eggs were exposed to 100%, 125%, 130% and 135% TDG supersaturated water. The results showed that the hatching rates were 78.25%, 75.35%, 71.30% and 67.50% at the 100%, 125%, 130% and 135% TDG respectively. The hatching rate decreased with increasing TDG levels. Furthermore, acute lethality experiments were carried out to investigate the interaction of TDG supersaturation and SS on Chinese sucker. Half‐year‐old juveniles were exposed to TDG supersaturated water with SS concentrations of 0, 200, 600 and 1,000 mg/L, and the TDG levels were 125%, 130%, 135% and 140% respectively. The fish exhibited abnormal behaviours and signs of gas bubble disease. Mortality increased with increasing TDG levels and SS concentrations. The Chinese suckers only survived for 2.5 hr at 140% TDG and 1,000 mg/L SS. Moreover, an increase in SS in TDG supersaturated water could cause a decrease in the median lethal time (LT50). When the TDG level reached 140%, the LT50 declines significantly at 600 and 1,000 mg/L SS. The interaction of TDG supersaturation and SS was significant at LT50 (F = 22.81, df = 9, p < 0.001). The results indicate that the combined effect of TDG and SS could be great on Chinese sucker.  相似文献   

15.
    
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16.
    
Discharged floods containing a large amount of suspended sediment (SS) can lead to total dissolved gas (TDG) supersaturation downstream of dams. The swimming ability of fish may be affected by TDG supersaturation and excessive SS. However, previous studies focused only on the separate effects of TDG and SS, ignoring their combined effects. In this study, juvenile rock carp and grass carp were selected to assess the interactive effects of TDG and SS on fish swimming ability. A totally crossed two-factorial design (six TDG levels: 100%, 115%, 120%, 125%, 130% and 135%; four SS concentrations: 0, 50, 100 and 150 mg/L) was set, and the critical swimming speed (Ucrit) and the burst swimming speed (Uburst) were measured. The findings indicated that the swimming abilities (Ucrit and Uburst) of both fish species decreased with increasing TDG levels and SS concentrations. Separate exposure to TDG significantly decreased the swimming abilities of the two fish species, whereas separate exposure to SS decreased only the swimming abilities of juvenile grass carp. Juvenile rock carp exhibited weaker swimming abilities than juvenile grass carp in TDG-supersaturated water. Additionally, the interaction between TDG and SS reduced the swimming abilities of juvenile rock carp and grass carp compared with a separate effect, but this reduction was significant only for the Ucrit of juvenile grass carp. This study demonstrates that TDG-supersaturated water containing SS during flooding may result in fish failure through fishways.  相似文献   

17.
气泡幕对鱼群有引诱、驱赶和阻拦作用,而气泡幕的这种作用是在鱼类的视觉、听觉、地震感觉和触觉的协同下完成的。本文介绍了气泡幕在鱼类行为中的应用,分析了气泡幕在鱼类行为控制方面的原理和作用,阐述了其在渔业捕捞、建设海洋牧场和减少港口噪音中的潜能和优势,以及使用与气泡幕相关的设备提高渔业高效节能和保护环境友好,并提出了气泡幕在鱼类行为控制方面的发展前景。  相似文献   

18.
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