高密度循环水养殖系统及运行效果分析

该研究构建了一套高密度循环水养殖系统,选用了双排污通道养殖池、竖流式固液分离器、转鼓式微滤机、紫外线灭菌器、沸腾式移动床生物滤器、CO₂脱气池、加压溶解氧气等先进水处理设施设备,以期研究养殖过程中的鱼类生长情况、水质变化情况以及应用推广价值。养殖富吉罗非鱼139 d,初始密度34.86 kg/m³,试验结果表明:罗非鱼生长情况良好,最终密度达108.97 kg/m³,存活率97.57%,饵料系数1.55。系统的水质良好,氨氮平均浓度0.32～0.42 mg/L,亚硝酸盐平均浓度0.02～0.03 mg/L,溶解氧平均浓度5.81～8.69 mg/L,水温平均24.23～24.95℃,pH值保持在7.6。经济性分析结果表明,该系统的运行成本相对较高,但由于罗非鱼品质高,受到消费者的认可和信赖,且该系统节水效果显著,具有较高的市场推广价值。     

封闭式循环海水系统大菱鲆高密度养殖研究

在封闭式循环海水养殖系统中进行了300d的养殖研究，在平均日换水量小于5％的条件下，大菱鲆平均体重由初始的10．4g，增至847g，平均日增重率为0．65％。成活率达到95．7％。养殖密度达到48．8kg／m^3，大菱鲆的生长情况良好，平均饵料系数为0．81，养成的商品鱼各项指标符合无公害大菱鲆的安全指标要求。研究结果表明，该系统适合高密度养殖大菱鲆，且是健康养殖模式，符合无公害水产品要求。     

全封闭循环流水式高密度养殖罗非鱼

工业化养鱼是解决高寒缺水地区水产品生产的有效途径。本文对原设计及建设中的养鱼场作了工艺上的改进，取得了较好的经济效益。     

循环水高密度养殖珍珠龙胆石斑鱼效果研究

为研究循环水高密度养殖珍珠龙胆石斑鱼[Epinephelus lanceolatu(♂)×Epinephelus fuscoguttatus(♀)]的养殖效果,在自行研制的循环水养殖系统中进行了试验。试验中对珍珠龙胆石斑鱼生长指标及养殖系统主要水质指标进行分析测定。结果显示,养殖期间的水质指标:水温26~29℃,盐度25~30,溶氧(DO)≥8 mg/L,氨氮浓度0.20~1.16 mg/L,亚硝酸盐氮0.05~0.40 mg/L。试验共持续250 d,分3个生长阶段:第1阶段87 d,密度由13.82 kg/m3增加到28.89 kg/m3,存活率95.28%,平均体重由(150±18)g增加到(329±42)g,特定生长率(SGR)为(0.90±0.06)%;第2阶段106 d,密度由28.89 kg/m3增加到53.36 kg/m3,存活率90.44%,平均体重由(329±42)g增加到(672±66)g,SGR为(0.67±0.02)%;第3阶段57 d,密度由46.98 kg/m3增加到69.50 kg/m3,存活率98.6%,平均体重由(676±52)g增加到(1 014±75)g,SGR为(0.71±0.02)%。养殖期间的平均SGR为(0.76±0.02)%,总存活率84.9%,饲料系数1.04,投入产出比为1∶2.02。本研究成果可为高密度养殖珍珠龙胆石斑鱼提供参考。     

陆基高密度循环水养殖的水质调控技术

利用先进的工厂化水产养殖技术与设施进行的全封闭高密度循环水养殖，具有节水、节地、节能、环保等优点。其成功的关键在于对养殖水体的水质调控。以下就陆基水产养殖的水质调控技术作一介绍。     

南美白对虾高密度养殖技术探讨

自2000年以来,北方地区引进南美白对虾获得成功,养殖面积逐年扩大,取得较好的经济效益.但由于天津地区池塘盐碱化严重,水质问题较多,不易调节;加上近两年养殖户盲目加大养殖密度,养殖管理跟不上,致使南美白对虾的养殖发生严重病害.特别是2004年有的养殖户几乎绝收,造成惨重的经济损失,严重挫伤了虾农的养殖积极性.     

对虾海水高密度养殖后期水质因子的昼夜变化规律

2008年7月5～6日,对广东汕尾红海湾对虾养殖场养殖87～88d的海水高密度半封闭养殖虾池水质进行每4h监测分析,旨在了解养殖后期昼夜水质变化状况,为合理和即时调控养殖后期水质提供相关理论数据。结果显示,24h内水质指标除化学需氧量（COD）和无机氮（DIN）基本稳定外,其他因子均有较大波动。其中氨氮（NH4＋-N）在3：00达到高峰,5：00落至低谷,9：00又达到高峰;亚硝酸盐氮（NO2--N）的变化却相反,在3：00落至低谷,5：00达到高峰,9：00又落至低谷;pH和溶解氧（DO）均在5：00降至最低,13：00上升到最高。结果表明,3：00～9：00是虾池水质变动的关键时期,应留意水质变化,适时采取合理增氧措施并投洒相应水质调节剂以提高ρ（DO）,减少NH4＋-N和NO2--N产生及降低其毒性。     

美国高密度水产养殖系统的程序控制技术

美国的农业通过强化、机械化和自动化已成为世界上生产效率最高的国家.温室苗圃、奶牛饲养、饲料生产和谷类灌溉系统等都采用了程序控制技术、高密度水产养殖系统也不例外.     

全封闭循环海水工厂化养殖水处理系统效果研究

<正>全封闭循环海水工厂化养殖是在原有的工厂化养殖基础上,配备循环水净化设施、设备,采用物理、化学、生物等净化方式把养殖废水转变成可再利用的养殖用水,使用优质的人工配合饵料和管理技术进行的高度集约化养殖方式。与先进国家技术密集型的循环水养殖系统相     

Evaluation of full-scale carbon dioxide stripping columns in a coldwater recirculating system

The objective of this research was to evaluate the dissolved carbon dioxide stripping efficiency of two types of 1-m tall structured plastic packing (tubular NORPAC and structured block CF-3000 Accu-Pac media) that were placed separately in two full-scale forced-ventilation cascade columns that were located within a coldwater recirculating aquaculture system at the Freshwater Institute. These two structured packing types were selected because they both provide large 4–5 cm void spaces that are either vertically-continuous (e.g. the tubular NORPAC) or an open structure with zigzagging but continuous void spaces (e.g. the blocks of cross-corrugated sheet media), which should reduce the likelihood of plugging with biosolids. Water flow rates were adjusted so that each cascade column was loaded with either 87, 136 and 187 m³/h water flow per m² of cascade column plan area (i.e. 35, 56 and 76 gpm/ft²). Air:water loading rates of 2.2:1 to 3.4:1, 5.1:1 to 5.6:1, and 9.5:1 to 9.9:1 were produced by setting the water flow rates through each column at 1.62, 2.54 and 3.48 m³/min, respectively, and then measuring the resulting air flow rate through the column under these conditions. As expected, the dissolved carbon dioxide removal efficiencies of both structured packing tested were found to depend on the volumetric air:water loading rate applied. The lowest volumetric air:water loading rate (i.e. 2.2:1 to 3.4:1) resulted in only 21–24% dissolved carbon dioxide removal. However, the dissolved carbon dioxide removal efficiencies rose to 32.4–33.6 and 35.8–37.2% for the medium and high air:water loading rates, i.e. 5.1:1 to 5.6:1 and 9.5:1 to 9.9:1, respectively. A second objective of this research was to determine if either packing would plug with biosolids after long-term operation. At the end of approximately 1 year of operation, both of the plastic packing materials were examined from the top of the packing to determine if potential fouling or plugging problems were apparent. A thin layer of brown biofilm covered both packings, but the biofilm did not appear to threaten water or airflow through the packing. In addition, no large mats of biosolids were visible from the top of either column. However, flooding at the interface of the support screen and the tubular NORPAC was suspected to have reduced air flows measured at the highest hydraulic loading rate tested (i.e. at 187 m³/h per m²), which coincided with the lowest air:water loading rates tested.     

月鳢的人工繁殖及水泥池精养试验

本文根据1998、1999年从广西引进的月鳢亲鱼及苗种,在厦门市水产中试基地进行人工育苗及苗种养成的生产试验结果,提出月鳢人工繁育及养成的技术要点。包括苗种的人工繁殖培养及水泥池精养两部分工艺流程。     

池塘循环流水养殖模式集污系统效能分析

为研究池塘循环流水养殖模式集污系统的效能,以草鱼为养殖对象开展试验,分析比较了沉淀池、养殖池上游及水源等处的总氮（TN）、总磷（TP）、悬浮物（SS）、高锰酸盐指数(COD_Mn)、氨氮（NH₄⁺-N）、亚硝酸盐氮（NO₂^--N）、硝酸盐氮（NO₃^--N）、溶解氧（DO）和酸碱度（pH）等水质指标。结果显示：集污系统可通过吸取和沉淀将鱼类排泄物分离出池塘,养殖水体中TN和TP的去除率分别为5.69%和63.42%。沉淀池的TP、SS、COD_Mn含量高于养殖池上游的,最高时分别高出221.85%、241.67%、102.18%。养殖池上游的TN、NH₄⁺-N含量与沉淀池没有明显差异,但NO₂^--N和NO₃^--N含量频繁高于沉淀池。水源、养殖池上游、沉淀池水体中的SS、pH、COD     

唐岛湾网箱养殖区底层水营养盐变化及营养状况分析

根据2004年8月、10月和2005年2月、5月对唐岛湾网箱养殖区现场调查,分析了网箱养殖区底层海水营养盐的季节变化,并对水质营养化状况进行了评价。结果表明,与对照点相比,唐岛湾网箱养殖对底层海水pH、DO影响不明显,对COD、NO2--N、PO34--P、NH4 -N影响相对较大。从无机氮营养结构看,DIN在冬季和春季以NO3--N为主,秋季NO3--N和NH4 -N二者相差不大,占主要比重,而在夏季NH4 -N所占比重最大。从A值和NQI值的统计结果看,在养殖活动较强的夏季和秋季,A值范围为1～2,为开始受污染等级,其他季节为水质处于良好等级,营养状态指数EQI值也呈夏季和秋季较其他季节高的变化趋势。     

脱二氧化碳装置对循环水养殖系统pH的影响

为了调节循环水系统中养殖水体的pH,根据气体交换原理,设计一种脱二氧化碳(CO_2)装置。采用该装置去除养殖水体中的CO_2,并对由于CO_2含量累积造成的pH下降进行调节,使养殖鱼类处在一个适宜的pH环境中。试验时水温控制在(25±0.5)℃,每1 h取水样测1次pH,每4 h测1次碱度。水样取自养鱼桶内的水,检测前先对水样用40μm孔径针头过滤器进行过滤处理,实验周期24 h。结果显示,循环水系统加装脱二氧化碳装置能有效去除CO_2,使水体稳定在一个适宜的pH范围(7.39~7.42);CO_2质量浓度呈降低趋势,24 h后由开始的13.16 mg/L降低到7~8 mg/L,降低近50%,而不加装脱二氧化碳装置的循环水系统CO_2质量浓度持续上升,24 h后增加到37 mg/L左右,pH持续降低,最终降低到6.72~6.81。研究表明,脱二氧化碳装置能够有效去除水体中的CO_2,使水体pH维持在一个适宜鱼类生长的范围。     

Quality costs in intensive fish culture: an analysis of African catfish farms in The Netherlands

A quality cost analysis was performed with the cooperation of six full-time African catfish, Clorias gariepinus, farmers in The Netherlands. The relative distribution of the quality costs does not fit a common quality cost model. Possible explanations for this observation are the absence of (1) feedback from customers and (2) well-defined quality criteria. The results show that it is likely that a considerable reduction in quality costs can be achieved with respect to sorting and rewatering. A further reduction is possible if agreement on quality criteria for African catfish can be reached.     

Simulation of inorganic nitrogen dynamics and shrimp survival in an intensive shrimp culture system

Nitrogenous wastes are major concerns in shrimp production and as a component of total farm wastes that impact the aquatic environment. This study describes a simulation model of the role of heterotrophic and nitrifying bacteria on nitrogen dynamics in intensive Litopenaeus vannamei (Boone) culture systems using different feeds and feeding strategies. The model represents: (i) use and remineralization by heterotrophic bacteria of nitrogen wastes and ammonia excreted by shrimp; and (ii) nitrification. The model was quantified using published and unpublished information. The model is multivariate, deterministic and uses a compartment model structure based on difference equations. Evaluation of the model consisted of simulating two indoor and one outdoor experiment that examined the effects of different feeds and feeding levels on nitrogen dynamics. In summary, the model is capable of qualitatively following inorganic nitrogen dynamics. Simulations investigating the effect of heterotrophic remineralization on total inorganic nitrogen suggested that this process may contribute up to 97% of the inorganic nitrogen in the system. This indicates that strategies to increase production, such as increases in feed protein levels or feeding rates, should be carefully evaluated before they are implemented. Future studies need to address bacterial community role in these systems and inorganic nitrogen toxicity mechanisms.