微孔管器水下曝气增氧技术

水体溶氧是好氧水生生物赖以生存的必要条件,水体溶氧的多少,对水质的保持和水产养殖活动的顺利进行非常重要。有人测算,草鱼在溶氧含量为5.5mg/L的水体中生长比在2.7mg/L的水体中生长增肉率提高9.88倍,饲料系数降低5.5倍。为了提高养殖水体溶氧含量,许多地方正在推广微孔管器水下曝气增氧技术。本文就此进行粗略的研究     

池塘溶氧的快速测定与管理

采用自制多功能采水器和溶氧参比卡,快速测定水体溶氧,及时采取溶氧管理措施,改善水体环境,防止池塘水质恶化和鱼类浮头或泛塘事件的发生,降低鱼类养殖风险,增加养殖户的经济收入。     

微孔增氧设施在三疣梭子蟹与脊尾白虾混养中的应用

<正>微管增氧设施即将纳米管铺设于池塘底部,通过管道传输把空气中的氧直接输送到水体底部,提高底层水体溶氧含量。与水车式、叶轮式增氧机相比,微管增氧设施具有增氧范围广、溶氧分布均匀、     

增氧设备在水产养殖中的应用

养殖水体中的溶氧水平关系到养殖水生动物的生存、生活和生长,进而关系到养殖成败和养殖效益的高低。根据对我国传统池塘养殖水体中溶氧水平的监测和数据分析,在水体总溶氧量中,70％左右的溶解氧来自于水体中的植物尤其是浮游植物的光合作用,30％左右来自于大气的溶入。通常情况下,水体上层的溶氧量较高,池塘底层水体的溶氧量较低,往往低于lmg／L。溶氧水平的高低直接影响着养殖鱼、虾的摄食量、饲料转化率以及生长速度。据有关资料显示,养殖鱼类在溶氧Nc3mg／L时的饲料系数要l：t4mg／L时增大1倍;在溶氧量7mg／L时,     

紊动对水体过饱和溶氧释放的影响初探

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。     

鱼类越冬期间死亡原因及对策

秋去冬至,越冬期间鱼类管理非常重要,如何使鱼类安全越冬,提高越冬成活率是养殖户关心的问题。笔者结合多年实践经验,谈谈鱼类越冬期间死亡原因及对策,使养殖户以此为鉴。1原因1.1越冬水体的含氧量通常越冬池发生死鱼大都是因为水中严重缺氧,因而,维持水体较高的溶氧量是确保鱼类安全越冬的重要条件。在越冬期间必须特别注意水体溶氧含量的变化。越冬水体中的溶氧来源于水生植物的光合作用,其产氧量与池水中的浮游植物的种类、数量和冰的透光度密切有关,而水体耗氧主要是水生生物的呼吸和有机物的分解。因此,根据越冬水体溶氧的来源和消耗途…     

鱼鳖混养浅谈

传统观念认为,鱼鳖互为敌害,不可同池共养。实践证明;只要处理得当,鱼鳖混养(以鱼为主混养鳖)和鳖鱼混养(以鳖为主混养鱼)不仅可行,且有共栖之利。首先,它们共栖可提高水中溶氧和热量,鳖是以肺呼吸为主的动物,其呼吸和摄食不停地在水体中上下运动,从而打破了水体的溶氧分界层,使水体的表层和底层的溶氧和水温得到了交流减少了晴天中午前后水体表层氧气过于饱和而逸走的损失,弥补了水体深层的“氧债””。这样既增加了水中的溶氧,又可增加水中的热量。其次,它们共栖可以促进有机物的分解。鳖生活在水体底层,促使沉积在池底的有机     

池塘养殖水体环境全程管理的“8+2”模式及应用(下)

<正>增氧:池塘水体溶氧决定了水体中生物的代谢活动、物质的形态和价态、氧化还原状态及微生物的分布情况。水体溶氧具有周期性变化,一般白天多,夜间、黎明前少;晴天多,阴雨天少;养殖动物密度过大,水体过肥,有机物多,可造成水体的呼吸作用加剧,导致水体阶段性缺氧;高温条件下,水体溶氧随温度升高而减少,但水产动物的耗氧增加,造成缺氧;水中还原性物质如硫化氢、氨氮等含量超标,也会造成缺氧。缺氧状态会造成毒性物质大量积累,增加毒性,对水生动物造成极为不良的后果。     

浅析过氧化钙在水产养殖中的应用

一、过氧化钙在水产养殖业中的应用 1．作为释氧剂增加水体溶氧过氧化钙作为释氧剂增加水体溶氧,典型地应用于有限的水域内、提高饲养密度而增加单位产量,并解决养殖水体缺氧而导致水产动物浮头或泛池现象,特别是在水产动物越冬期。     

一种大水体太阳能自动增氧装置的研发与试验

研发一种大水体太阳能自动增氧装置,为大水体的缺氧、水体污染提供一种解决方法。太阳能自动增氧装置由太阳能光伏发电系统、检测与智能增氧系统、自动化驱动系统组成。光伏发电系统充分利用太阳能资源,解决了电能消耗问题;检测与智能增氧系统实现了增氧过程中氧溶解浓度检测和智能感应运行;自动化驱动系统通过智能感应信号和电子差速控制系统实现增氧机原地转向、转弯和直行3种运动模式的移动,增加了增氧面积。使用太阳能自动增氧装置增氧试验表明,80 min内1 m水深处溶氧量增加0.79 mg/L,2 m水深处溶氧量增加0.78 mg/L,3m水深处溶氧量增加0.77 mg/L,4 m水深处溶氧量增加0.78 mg/L;改善水质试验表明能有有效提高水体溶氧,降低氮磷含量;养殖试验表明,增加鲤产量35.3%、鲢鳙产量31.2%。     

Split Ponds Effectively Overwinter Golden Shiners

Baitfish producers have expressed interest in adopting the split‐pond production system. However, confining fish to 20% of the pond area in split‐pond systems effectively quintuples fish density within the culture unit as compared with densities in open ponds. Winter conditions are known to be relatively more stressful on smaller fish, and high densities within split‐pond culture units could increase losses. A 139‐d study was conducted during the winter to compare the production of golden shiners, Notemigonus crysoleucas, in traditional earthen ponds and split ponds at two densities. Golden shiners were stocked at 646 kg/ha or 1292 kg/ha (ca. 370,500 or 741,000 fish/ha, respectively) into 12, 0.04‐ha, netted earthen ponds (six split ponds and six traditional). Feeding rate, nightly aeration hours, and daily circulation hours were reduced when water temperature decreased. At harvest, net yields were significantly lower in the split ponds as compared with traditional ponds at each density (53 and 113 kg/ha less in the low‐ and high‐density split‐pond treatments, respectively). Estimated survival was high (>87%) and did not differ among treatments. Results showed that, although net yield was reduced, small baitfish could be successfully overwintered in split‐pond culture units in preparation for the spring crappie market.     

池塘养殖水体不同水层水质变化研究

为探讨池塘养殖水体时间和空间上的变化特征,在上海市标准化养殖池塘里进行了水质参数监测和分析,研究了池塘上层、中层、下层不同水层的水质变化情况。结果表明:一年中池塘水质呈季节性变化,氨氮均值在9—11月最高,在5月份最低;溶氧均值在9—11月最低,在12月至次年3月最高;pH无明显季节性变化。不同水质参数日变化研究发现,一天中氨氮值在6:00左右最高,在17:00左右最低;溶氧最高值出现在15:00—17:00,最低值在5:00左右;pH在1:00最低,14:00左右最高。养鱼池塘水体有较明显的分层现象,上层、中层、下层不同水层的氨氮、溶氧、pH均有差异。一天中氨氮与溶氧总体呈负相关性(t<0.05),溶氧值升高时氨氮值下降。     

不同养殖结构鱼塘能量生态学研究

本文从养针池生态系统利用能量利用各环节,分析了两种不同养殖结构鱼生态学能量利用效率。主养草食性鱼类,其输入的总补助能,光合能、生物能的转换效率分别为９．８６％、６．９２％、１０．１０％;其生产吨鱼总补且能、光合能、生物能分别为４６．６４ＧＪ、６６．４６ＧＪ、４５．５４ＧＪ。而对于主养滤食性鲢、鳙的池塘,其对应的指标 ８．３．％、３．７５％、８．６６％、４６．９９ＧＪ、１０５．５２ＧＪ、４５．７３Ｇ     

Modeling industry-wide sediment oxygen demand and estimation of the contribution of sediment to total respiration in commercial channel catfish ponds

Data collected from 45 commercial channel catfish, Ictalurus punctatus, ponds were used to develop empirical models predicting sediment oxygen demand (SOD). Seven acceptable models were combined with a Monte-Carlo sampling distribution to predict industry-wide sediment oxygen demand (SOD_i). The SOD_i values obtained from the best equation were used in simulations to assess the effect of diurnally varying water column dissolved oxygen (DO) concentrations on SOD and the effect of pond water depth on the contribution of SOD to overall pond respiration. Estimated SOD_i ranged from 62 to 962 mg m⁻² h⁻¹, with a mean of 478 mg m⁻² h⁻¹. There was a 95% probability of mean SOD_i being ≥700 mg m⁻² h⁻¹. The effects of diurnal variation in DO concentration in the water column on expression of SOD was modeled by combining maximum SOD_i, an empirical relationship between DO and SOD, and simulated pond DO concentrations. At DO concentrations >15 mg l⁻¹, diel SOD in catfish ponds exceeded 20 g O₂ m⁻² day⁻¹. But when average diel DO was <4 mg l⁻¹ and the range of DO concentration was 6–8 mg l⁻¹, SOD decreased to 13 g O₂ m⁻² day⁻¹ because DO availability limited the full expression of potential SOD. Respiration totals for sediment (average SOD_i), plankton, and fish respiration were calculated for pond water depths ranging from 0.25 to 4 m. Although whole-pond respiration increases as pond depth increases, the proportion of total respiration represented by sediment decreased from 48 to 10% by increasing water depth over this range. The results of these studies show that SOD is a major component of total pond respiration and that certain management practices can affect the impact of SOD on pond oxygen budgets. Mixing ponds during daylight hours, either mechanically or by orienting ponds for maximum wind fetch, will increase oxygen supply to sediments, thereby allowing maximum expression of SOD and maximum mineralization of sediment organic matter. Given a mixed condition caused by wind or other artificial means, the construction of deeper ponds increases the total mass of DO available for all respiration, causing nighttime DO concentrations to decline at a slower rate, reducing the need for supplemental aeration. Because a pond’s water volume decreases over time from sediment accumulation, annual aeration costs will increase with pond age. Constructing ponds with greater initial depth will therefore reduce long-term cost of aeration, allow more flexible management of pond water budget, and reduce the long-term expense associated with pond reconstruction.     

稀土在池塘养鱼中使用效果初试

在养鱼池塘中泼洒稀土与结合饲料中混拌稀土的养鱼方式，可使鱼类单产增加14.41～18.51%，降低每公倾鱼塘鱼类死亡率27.27%，投入与产出比1：5以上。     

Pond Culture of Larval and Juvenile Cobia,Rachycentron canadum,in the Southeastern United States

Abstract

The potential of growing larval and juvenile cobia, Rach-ycentron canadum, in ponds was investigated. Larval cobia, obtained from tank spawning of wild-caught adults, were stocked 48-72-h post-hatch at a rate of 700,000/ha into three fertilized 0.25-ha ponds. At one week post-stocking (WPS), fish were observed consuming formulated feed. Growth was rapid, with specific growth rates (SGR) ranging from 12.5-19.2% body weight/day. At harvest (5 WPS) fish reared in two ponds weighed 7.9 and 9.3 g and total length (TL) was 118.9 and 129.3 mm, respectively (all fish reared in remaining pond died the night prior to harvest due to aerator failure). Feed conversion ratio (FCR) was 3.8 for both ponds and survival was 5.3 and 8.5%. Low survival rates were thought to be due primarily to cannibalism. Immediately after harvest, fish were restocked into two 0.25-ha ponds at a stocking rate of 14,400/ ha. Fish were fed formulated, pelleted feeds. Growth was rapid up to ～9 WPS, after which pond water temperatures declined. Ponds were harvested at 13 and 15 WPS, respectively. Final weight of fish was 309.9 and 362.5 g. Final TL was 343.1 and 355.7 mm. FCR was 3.8 and 4.5 and survival was 27.5 and 30.5%. Major losses of fish were associated with avian predators and possibly a toxic algal bloom. Results of trials indicate that cobia larvae and juveniles can be reared in pond-based culture systems, however additional research is needed to refine this approach.     

美国大口胭脂鱼的人工繁殖技术研究

用专塘培育大口胭脂鱼亲鱼，采用人工催情、产卵、受精、池塘孵化、培育等方法，催产美国大口胭脂鱼92组，培育出1.5-2.0cm的苗种283万尾。     

Impacts of long-term changes in fishery management on the trophic level water quality in Czech fish ponds

The management of Czech fish ponds changed little from the Middle Ages until the end of the nineteenth century. The intensification of fish production was initiated during the first half of the twentieth century. During the 1930s, liming and manuring of the ponds became common. A greater density of stocking led to the use of artificial feeds in the form of pellets and grain. These changes in pond management have led to an increase in fish production from 50 to > 500 kg ha¹ year¹ over the last 5 decades. At the same time, the quality of the water and sediments has been deteriorating, and the functioning of the pond ecosystem has been disturbed. There are now massive blooms of phytoplankton, especially cyanobacteria, accompanied by great fluctuations in the oxygen concentration and pH. Data collected since 1925, when systematic research on the ponds started, allow the mechanisms responsible for the changes to be traced.     

Natural food intake by juvenile Arapaima gigas during the grow‐out phase in earthen ponds

In carnivorous fish species, zooplankton is one of the main food items in the early life stages and some fish species continue feeding on such food items further along the life stages even in the farming environment. In this study, the intake of natural food items was assessed in juvenile pirarucu Arapaima gigas reared in earthen ponds. Juvenile pirarucu (12.2 ± 4.32 g and 12.1 ± 1.13 cm) were stocked in fertilized earthen ponds (240 m²). For the analysis of the fish stomach content and plankton in the pond water, the fish and pond water were sampled weekly for 75 days and biweekly until the fish reached a mean weight of 750 g. Although artificial feed was used, pirarucu also ingested the natural food available in the pond water. Among the zooplankton, pirarucu demonstrated feeding preference for cladocerans despite the abundance of rotifers and copepods. Cladocerans were present in more than 80% of the stomach contents of fish up to 300 g and in 65%, 45% and 17% of fish of 301–500 g, 501–700 g and 701–900 g respectively. Copepods were present only in fish up to 500 g at low abundance. High ingestion of insects and plant material was observed in the stomach content of fish of all size classes. The results demonstrate that juvenile pirarucu ingest natural food available in the farming pond and suggests that the adoption of pond fertilization practices may have positive effects on fish growth performance.     

生态沟渠+稳定塘系统处理山区农村生活污水的研究

研究流经生态沟渠+稳定塘系统的生活污水中悬浮物、氨氮、总氮、总磷、CODcr等指标的沿程变化以及去除效率,为探索山区农村生活污水治理模式提供依据和参考。生态沟渠由原农田排水渠经拓宽、种植植被改建而成,总长约150 m;稳定塘包括沉淀净化塘、生物净化塘和生物强化净化塘,分别栽种植物、栽种植物+吊养河蚌、栽种植物+放养鲢鳙,总面积约1 230 m2。在集水池出口、生态沟渠出口、稳定塘各塘出口各设1采样点共5个采样点。试验期间连续进水,进水平均流量约7 m3/h,系统总水力停留时间(HRT)约102 h,其中生态沟渠段约5.4 h、稳定塘段约96.6 h,首次采样在连续进水稳定运行1周后进行。在水力停留时间约为4 d的条件下,流经该系统的生活污水黑臭消失,浊度下降,出水DO饱和度达到65%以上,进水SS、NH3-N、TN、TP、CODcr的平均去除效率分别达到84.9%、70.1%、49.6%、44.9%和80.5%。生态沟渠段对SS具有较好的去除效果,达到40.1%,占系统总去除量的47%。系统最终出水可达到城镇污水处理厂污染物排放二级标准(GB18918-2002)。生态沟渠+稳定塘系统具有建造灵活、无需动力条件、运行成本低廉等特点,在小流域山区农村具有一定推广和应用前景。