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。     

The evolution and future of pond and marine fish culture in Hong Kong

Abstract

This paper provides a case study of the evolution of the freshwater food fish and marine food fish culture industries in Hong Kong as a highly urbanized and polluted metropolis. This study lends support to the thesis that marine fish culture is generally more sustainable than pond fish culture, owing to the fact that oceanic resources are relatively less scarce than land resources ‐ even though the transaction costs of delineating and enforcing private property in the former are much higher. The case study gives a brief historical account of the evolution of the freshwater food fish and marine food fish culture industries in Hong Kong, identifies the technical inputs constraining the survival and prospects of these industries, and evaluates the relevance of the private property rights approach to their sustainability. Examination of the culture industries reveals the differences in property right characteristics of both industries. In addition to the differentiation in the degree of privatization between freshwater food fish and marine food fish culture, the major characteristics and inputs for culture practices in both industries are also examined. A qualitative evaluation of the relative significance of these inputs to the sustainability of the culture industries is provided. It is argued that the escalation in the factor price of land will destroy the local pond fish culture industry even though it is more ‘private’ than marine fish culture, notwithstanding the fact that substantial areas of intertidal ponds are owned by government and that in‐filling of fishponds have been subject to stringent planning control. The policy implications of the case study are spelled out.     

Seasonal stratification in fish culture and irrigation reservoirs: potential dangers for fish culture

Dual-purpose reservoirs for field irrigation and fish culture are characterized by the simultaneous (a) increase in standing crop biomass and feeds during the fish culture period and (b) decrease of water level due to irrigation. This management practice affects stratification, which in turn affects water quality and may affect the fish stocked. To study the limnology of dual-purpose reservoirs, an extensive sampling programme including automatic continuous recording and manual water sampling in deep and shallow reservoirs was carried out. This paper describes limnological changes during the week in which a 3 month long seasonal stratification ended and fish kills occurred. Management implications of stratification are also discussed. The data presented are the first continuous records of this process in this particular type of water body.     

深水网箱养鱼业的现状与发展趋势

深水网箱是指设置在相对较深海域,养殖容量较大,具有较强的抗风浪、流性能的海上养殖设施。它在拓展养殖海域、减轻沿岸环境压力、提高养殖鱼的质量、增加养殖效益等方面已显示出明显的优势。由于它是新兴的一种设施渔业,能包容的高新技术多,涉及材料、机械、电子、苗种、饲料、环境等诸多方面,当前仍有不少技术问题需要解决。建议今后对此产业加强宏观管理和指导,改进设施,改善管理,加强科技投入,提高业者素质,扩大经营规模,提高产品质量,借鉴世界上渔业发达国家的经验,使这一产业健康、持续发展。     

大水面网围精养对水环境的影响及其对策

大水面网围精养对水环境的影响及其对策吴庆龙，陈开宁，高光，范成新，季江，隋桂荣，周万平（中国科学院南京地理与湖泊研究所，２１０００８）关键词网围养鱼，水环境，对策ＥＦＦＥＣＴＳＯＦＰＥＮＦＩＳＨＣＵＬＴＵＲＥＯＮＷＡＴＥＲＥＮＶＩＲＯＮＭＥＮＴＡＮＤ...     

Use of artificial substrates to enhance production of freshwater herbivorous fish in pond culture

Two trials were conducted in mud‐bottomed concrete tanks to assess the potential of using artificial substrates to enhance fish production in ponds. Three substrate types were tested: bamboo poles, PVC pipes and sugarcane bagasse bundles. In one trial, periphyton was grown on the substrates in the absence of fish. In the second trial, masheer (Tor khudree Sykes) fingerlings were stocked at three densities. Results showed a significant effect of substrate type on fish growth (P≤ 0.001) and on net fish production (P≤ 0.05), with best growth in the tanks using the bamboo substrate. In the bagasse treatment, 100% fish mortality occurred. Highest extrapolated periphyton‐based gross fish yield (i.e. without feed inputs) was 450 kg ha^?1 90 d^?1 with PVC and 491 kg ha^?1 90 d^?1 with bamboo substrate. The best periphyton growth occurred on bamboo, followed by bagasse and PVC. Without fish, mean periphyton biomass during the culture period was 0.56–1.20 mg cm^?2 on bamboo [ash‐free dry matter (DM)], against 0.09–0.36 mg cm^?2 on PVC and 0.20–0.59 mg cm^–2 on bagasse. No clear effect of fish density or water depth on periphyton biomass could be seen. Only on bamboo, fish density seemed to have a negative effect on periphyton ash‐free dry matter and a positive effect on pigment content (chlorophyll‐a and phaeophytin). Periphyton from bamboo had a lower ash content (38–47% of DM) than from PVC (54–55% of DM) or bagasse (51–58% of DM). It is concluded that substrate type has a strong effect on periphyton productivity and composition, and on fish productivity. Good fish production was achieved without feed inputs. More research is needed to study the economic viability of periphyton‐based systems in the context of Indian aquaculture.     

Fisheries and cage culture of three reservoirs in west Java, Indonesia; a case study of ambitious development and resulting interactions

Abstract The interactions between cage culture and wild fishery activities in three Indonesian reservoirs, Saguling, Cirata and Jatiluhur, of the greater Ciratum watershed, West Java, were evaluated using historical data and interviews with cage culture operators. In all three reservoirs, cage culture of common carp, Cyprinus carpio L., and later of common carp and Nile tilapia, Oreochromis niloticus (L.), were encouraged as an alternative livelihood for persons displaced by the impoundment. Currently, a two‐net culture system, locally known as ‘lapis dua’, in which in the inner cage (7 × 7 × 3 m) is used for common carp culture and the outer cage (7 × 7 × 5/7 m) is stocked with Nile tilapia, is practised. On average each cage is stocked with approximately 100 kg fingerlings each of common carp and Nile tilapia. The numbers of cages and production of cultured fish has increased in the reservoirs, but total and per cage production began to decline from about 1995 in Saguling from 2200 kg cage^?1 in 1989 to <500 kg cage^?1 in 2002, and in Cirata from a peak of approximately 2300 kg cage^?1 in 1995 to approximately 400 kg cage^?1 in 2002. In Jatiluhur, which has a considerably lower cage density, total fish production and production per cage has increased since 2000, and currently is approximately 4000 kg cage^?1, close to production in the early years of cage culture activities. The cage culture operations also resulted in substantial nutrient loading, estimated at 3.2, 15.2 and 3.1 t of nitrogen and 134, 636 and 128 kg of phosphorous per year in the maximum years of production for Saguling, Cirata and Jatiluhur reservoirs, respectively. In later years, when cage culture production was high, fish kills occurred in the cages, and in Jatiluhur reservoir coincided with a dramatic decline in wild fishery catches. An attempt is made to determine the maximum number of cages for each of the reservoirs that will bring long‐term sustainability of cage culture operations and the wild fisheries in the three reservoirs.     

鱼虾蛏在海水池塘的混养试验

本文报道双斑东方鲍、日本对虾及缢蛏在一口面积为1.6ha的海水池中混养试验情况.经合理搭配、精心饲养,通过生物间的相互作用和人为调节,使养殖池形成一个稳定良好的生态系统,有效地抑制病虫害的发生,鱼、虾、蛏混养的成活率、生长速度、产量均较为理想,获得了显著的养殖效果.     

Use of geographical information systems as a tool for predicting fish yield in tropical reservoirs: case study on Sri Lankan reservoirs

Use of geographical information systems (GIS) in inland fisheries has hitherto been essentially restricted to site evaluation for aquaculture development and assessment of limnological changes in time and space in individual water bodies. The present GIS study was conducted on the land-use pattern of the catchments of nine reservoirs in Sri Lanka, for which detailed fishery data, viz. yield, fishing intensity, landing size of major constituent species, together with selected limnological data such as conductivity and chlorophyll- a , were available. Potential statistical relationships (linear, curvilinear, exponential and second-order polynomial) of fish yield ( FY , in kg ha⁻¹ yr⁻¹) to different land-use patterns, such as forest cover ( FC , in km²) and shrub-land ( SL , in km²), either singly, or in combination, and/or the ratio of each land type to reservoir area ( RA in km²) and reservoir capacity ( RC in km³), were explored. Highly significant relationships were evident between FY to the ratio of SL and/or FC + SL to RA and/or RC . Similarly, the above land-use types to RA and RC ratios were significantly related to limnological features of the reservoirs. The relationships of FY to various parameters obtained in this study were much better correlated than those relationships of FY to limnological and biological parameters used in yield prediction in tropical and temperate lacustrine waters previously.     

池塘养殖和大湖养殖对“华海1号”团头鲂鱼肉品质的影响

为探究不同养殖模式下新品种“华海1号”团头鲂的品质差异，实验以不同养殖模式(池塘组及大湖组)的“华海1号”团头鲂为对象，采用色差仪、质构仪对其表观及质地进行测定，采用超高效液相色谱仪或气相色谱-质谱联用仪等对营养特性和风味物质进行测定。结果显示，大湖养殖团头鲂肉质的亮度、白度、弹性、咀嚼性、回复性均显著高于池塘组，且大湖组肌肉水分含量更高，粗脂肪含量更低。池塘组和大湖组鱼肉EAA/TAA及EAA/NEAA比值分别为0.41、0.82以及0.38、0.72，均符合FAO/WHO推荐的理想必需氨基酸构成。池塘组必需氨基酸指数虽高于大湖组，但其必需氨基酸中仅赖氨酸含量显著高于大湖组，而大湖组鱼肉中非必需氨基酸及半必需氨基酸含量分别为池塘组的1.05倍及1.01倍，且大湖组总脂肪酸含量下降21.09%，多不饱和脂肪酸占比提升4.00%,EPA和DHA含量分别为池塘组的14.20倍和7.51倍，故大湖组鱼肉营养更为均衡。池塘组鱼肉谷氨酸及丙氨酸TAV值均大于1，大湖组赖氨酸TAV值大于1，但大湖组鱼肉中鲜味及甜味氨基酸总占比更高，苦味氨基酸总占比更低，且大湖组呈鲜味的AMP及IMP含量为池塘组的...     

水射流空化强化光催化氧化技术在养鱼污水处理中的应用初探

研究了水射流空化强化TiO2光催化氧化技术处理养鱼污水的效果,同时考察了单独的水射流空化处理、光解处理、光催化氧化处理的效果。试验结果表明:水射流空化强化TiO2光催化技术处理养鱼污水0.5 h后,杀菌率达97%;处理4 h后,氨氮和COD的去除率分别达25%和29%。在降解氨氮和COD方面,水射流空化技术和TiO2光催化氧化技术结合表现出明显的协同效应。水射流空化强化光催化氧化是一种绿色无污染的工艺,而且高速射流产生的冲击波对水体可以起到增氧的作用,有利于养殖鱼类的生长。     

工厂化循环水与静水养鱼模式综合效益分析

在工厂化养鱼车间静水与循环水养鱼2种运行模式的基础上,运用经济预测与决策技术,根据随机型需求的投资模型决策的分析方法,建立了2种风险决策模型,设定相应的技术指标体系,分别从利润贡献、运行成本、设备利用、效益风险、生态效益等方面进行了综合评估和全面分析,阐明了循环养殖模式节水降耗、提高设施设备利用率等优势,为工厂化养鱼节水降耗、规模化、可持续健康发展提供参考依据.     

Effects of tilapia (Oreochromis niloticus L.) stocking and artificial feeding on water quality and production in rohu–common carp bi‐culture ponds

Previous research showed that stocking 1.5 rohu (Labeo rohita) and 0.5 common carp (Cyprinus carpio) m⁻² yields the highest production in small holder ponds in Bangladesh. The present study looked into the effects of additional stocking of Nile tilapia (Oreochromis nilotica) in fed or non‐fed ponds on water quality and fish production. A low, additional stocking density of 0.2 Nile tilapia m⁻² was tested. All treatments were executed in triplicate in 100 m² ponds and the duration of the experiment was 4.5 months. The results showed that tilapia addition increased nutrient concentrations and reduced total suspended solid concentration and phytoplankton biomass (P<0.05). Tilapia stocking resulted in additional production without affecting the growth and production of rohu and common carp. Supplemental feeding increased the nitrogen and phosphorus concentrations, phytoplankton availability and the growth and production of rohu and common carp (P<0.01). The combination of supplemental feeding and tilapia stocking resulted in a higher net yield than the other treatments (P<0.05). Stocking 1.5 rohu, 0.5 common carp and 0.2 tilapia m⁻² in fed‐ponds is a good culture combination for polyculture farmers in South Asia.     

深型水库溶解氧分层规律及其机制探究——以万安水库为例

溶解氧（DO）是衡量生态状况的重要指标,对生态系统的平衡至关重要。为探究深型水库DO分层的规律及其影响机制,于2022年监测了九龙江万安水库的理化指标及营养元素的垂向分布,并分析库区的DO分层规律及影响因素。结果表明：2月属万安水库混合期,呈贫营养状态,DO垂向平均浓度高达6.70 mg/L,DO变化受浮游植物分布及“翻库”影响;5月属热分层形成期,处中营养状态,水体在内源产氧减少和原位DO消耗驱动作用下出现温跃层溶解氧极小值,36 m以下水体处于缺氧状态;8月为热分层稳定期,处中度富营养化,表层DO最大浓度达12.00 mg/L以上,在35 m深度出现DO极大值,水体热分层阻碍DO补充、内源产氧减弱是造成热分层稳定期水体上层大范围缺氧的主要原因;10月为热分层消退期,呈中营养状态,DO垂向平均浓度仅为0.77 mg/L,水深2.79 m以下水层皆处于缺氧状态。热分层时期DO垂向变化受到水体热分层、营养水平、污染状态及浮游植物生长分布等因素的影响,热分层从物理角度影响DO分层,营养水平及污染状态可以影响DO的产耗机制,而库区水体浊度通过影响浮游植物的垂向分布进而对DO浓度产生影响。本研究探明了水层缺氧及变温层DO极小值等现象出现的原因,深入探讨了DO变化规律与营养元素生物地球化学循环间的关系,为维护库区水生态健康提供科学依据。     

投饵网箱养鱼促进温杖子水库渔业高速增产的生态经济效益分析

温杖子水库按养鱼水面单位面积承受２２００ｋｇ／ｈａ网箱鱼的负载量设置网箱，建立以网箱养鱼为重要环节的水库新型渔业生产结构体系。三年中，水库水面鱼产量（含网箱鱼产量）由１４５．５ｋｇ／ｈａ上升到２６６．７１ｋｇ／ｈａ，年总产量增长１８．３倍；渔业投入资金年利润率达７１．９％；网箱养鱼的投入总能量转换效率提高了６．０３－６．３６％。合理开发和保护了水库渔业资源，促进了温杖子水库渔业的高速增产。     

Effects of water flow velocity and fish culture on net biofouling in fish cages

The effects of water flow, fish feed and cage position on net biofouling was examined in a floating cage fish farm. Fouling of 16 mm mesh net panels suspended inside and outside net cages and exposed to different treatments were monitored weekly until net apertures were completely occluded by the fouling organisms (8 weeks). Results indicate a dramatic reduction in water flow velocity throughout the fish farm due to the cage units themselves and net biofouling. The reduced water flow (<10 cm s^?1) inside net cages promoted rapid net biofouling, while rapid water flow outside the net cages (>25 cm s^?1) kept the net fouling organisms at bay. Although fish rearing in net cages with inputs of commercial pellet feed increased sessile biofouling (222% higher than outside the net cages) and non‐sessile biofouling (570% higher), the type of fish feed used did not significantly affect biofouling development. The study recommends that the geometry of serially arranged net cages, as commonly deployed in tropical tidal estuaries, be reconfigured to improve flow through in order to minimize the impact of fouling.     

Effect of different management practices on water quality of intensive tilapia culture systems in Israel

Commercial intensive aquaculture systems werebuilt and are managed in a somewhat differentway in each farm. To evaluate the effects ofseveral management procedures on water qualityin intensive fish ponds, data from severallocations, times and culture conditions indifferent farms were collected and are hereinanalyzed through multivariate statistics.Water quality in the intensive ponds depends onthe water entering, the biological processeswithin, and the water leaving the ponds. Areservoir used as source and sink water supplied theintensive ponds with higher organic loadingthan clear source waters, and its phytoplanktoncontent affected nitrogen cycling within theintensive ponds. The systems with a reservoirhad better water quality in the intensive pondsthan those with only clean source water.Within the ponds (1) compared to paddle-wheelaeration, aeration by pure oxygen increasedoxygen concentration, improved nitrificationand promoted decomposition that reduced organicloading. (2) In concrete ponds accumulation oforganic matter and development of anerobicconditions on the pond bottom was higher thanin the slippery plastic-covered ponds. (3) Allintensive ponds provided good growthconditions, tilapia biomass having relativelysmall influence on water quality. Only inpaddle-wheel aerated ponds did increased tilapiabiomass increased inorganic nitrogen compoundsand soluble phosphorus through excretion, andreduce organic nitrogen through a moreefficient removal of food particles.Water leaving the ponds removes matteraffecting water quality within the pond. (1)Draining sediments accumulated on the bottomavoided development of anaerobic conditionswhere denitrification and phosphorus liberationcan occur. (2) Water exchange removed particleswith nitrifying bacteria and algae that absorbnutrients. A high water exchange rate may havea negative effect from the water quality pointof view and from the extra costs incurred inenergy and feeds washed out.The processes described occur simultaneouslythroughout the culture period and shape waterquality dynamics in the ponds. This researchcontributed to the understanding of howmanagement procedures affect the differentphases of water quality dynamics in real-scaletilapia commercial intensive systems.