River pen culture of giant freshwater prawn Macrobrachium rosenbergii (De Man) in southern Vietnam

A technical and socio‐economic survey conducted in the Dong Thap province of Vietnam to assess the current status of river pen culture of giant freshwater prawn Macrobrachium rosenbergii (De Man) showed that pen culture, which has been developed and operated by farmers' indigenous knowledge, requires more study in order to optimize stocking density and to assess its environmental impacts. In this study, the prawn pens were of rectangular shape, with an average size of 209 m². Prawns were stocked in June at an average density of 62 pieces m^?2 and fed on farm‐made feed and were harvested 2–4 times starting from 4 months after stocking until late December or the following January. The average prawn yield was 0.52 kg m^?2 year^?1, ranging from 0.14 to 1.6 kg m^?2 year^?1. The average net return was US$0.71 m^?2 year^?1, ranging from US$1.24 to 4.37 m^?2 year^?1. About 73% of the farmers achieved positive net returns. The top five constraints for prawn pen culture were lack of knowledge of culture technologies, poor water quality, disease problems, poor quality of wild seed and lack of capital. Almost all farmers have no environmental awareness, and environmental regulations for prawn pen culture have not been established. Field measurements showed that all measured water quality parameters were within the range for good growth of giant freshwater prawns, and indicated that there was no significant accumulation of nutrients and organic matter at the bottoms of rivers or canals.     

中国近海海藻养殖及碳汇强度估算

海藻养殖是渔业碳汇的重要形式,碳汇生态功能显著。本实验以1999—2012年《中国渔业统计年鉴》统计数据为基础,对中国及浙江近海藻类养殖的产量、结构进行了分析,并对其固碳强度进行了估算。中国近海海藻养殖以海带、裙带菜、紫菜、江蓠等为主,期间年均总产量为141.87万t,各类海藻养殖产量所占比例分别为海带(60.29%)、裙带菜(7.92%)、紫菜(5.67%)、江蓠(5.39%)。浙江近海海藻养殖以紫菜、海带、羊栖菜、苔菜等为主,各类海藻养殖产量所占比例分别为紫菜(51.83%)、海带(27.73%)、羊栖菜(12.72%)、苔菜(1.27%)。浙江近海海藻养殖总产量占全国总产量的份额不高(2.55%),但养殖结构独特,部分种类的海藻养殖产量在全国同种类海藻养殖量中占有较高份额,其中苔菜占83.00%,羊栖菜占68.29%,紫菜占23.53%。1999—2012年,全国海藻年均固碳量为41.85万t/a,固碳量在2012年最高达51.50万t,整体呈现上升趋势。其中,海带年均固碳量在各类海藻中最高达26.45万t/a,其次是裙带菜3.23万t/a、紫菜2.24万t/a、江蓠2.01万t/a。浙江近海养殖海藻年均固碳量为1.03万t/a,约占全国年均固碳量的2.47%。为满足低碳经济发展的需求,建议加强近海自然碳汇及其环境的保护和管理,大力发展以海水养殖为主体的碳汇渔业,开展碳汇渔业关键技术与产业示范工程研究及海洋生物碳汇功能与碳汇渔业潜力的基础科学研究。     

Towards sustainable freshwater prawn aquaculture – lessons from shrimp farming, with special reference to India

The annual increase in farmed freshwater prawn production in the world during the decade ending 2001 has been estimated as 29% and that during 1999–2001 as 48%, the production in 2001 being about 300 000 mt (all Macrobrachium species). Between 1999 and 2003 the annual increase in farmed Macrobrachium rosenbergii production in India was about 80%, production reaching 30 450 mt in 2002–2003. This log phase of production followed the rise and fall of shrimp farming in the country. Several shrimp farming ventures collapsed in the 1990s, owing to degraded environment and diseases, abetted by lack of awareness and inadequacy of information on the culture systems and their interactions with other human endeavours. This shrimp farming experience has made the aquafarmer and other stakeholders aware that while aquaculture has a high potential in ensuring food and nutritional security and livelihood, besides profit to the farmer and socio‐economic benefits to local communities, it is likely to slip from sustainable development pathways if adequate understanding, improved management practices, governmental policies and plans for implementation and regulation to ensure sustainability are not in place. The lessons learned from shrimp farming can help in steering the development of sustainable freshwater prawn aquaculture in India and elsewhere.     

团头鲂水库网箱养殖试验

在网箱中进行团头鲂（Megalobrama amblyocephala)鱼种,成鱼养殖,鱼种箱平均产量470kg,平均尾重81．5g,个体净增重12．19倍,平均饲料系数2．22,成鱼箱平均产量828.65kg,平均尾重435g,个体净增重7．53倍,平均饲料系数2．25。     

The effects of tank colours on the growth and survival of cuttlefish (Sepia officinalis,Linnaeus 1758) hatchlings and juveniles

The effects of different tank colours (white, yellow sandy and black) on the growth, mortality and biomass production were studied for hatchling and early juvenile cuttlefish. For hatchlings, the use of different colour tanks did not promote differences in growth due to the higher variability (standard deviation) found in the white‐ and sand‐coloured tanks. Black tanks promoted the lowest and highest values for total mortality and biomass respectively. For juveniles, the use of different tank colours promoted different growth (P<0.05), but not mortality. Black tanks promoted the best results in terms of growth and biomass. The results obtained in the present study advise the use of black (or dark colour) tanks in the hatchling and early juvenile stages to reduce the standard deviations associated with growth, mortality and biomass production. This will contribute to minimize problems associated with slow and fast growers and competition.     

不同养殖模式下2龄暗纹东方鲀的生长特性

为探寻暗纹东方鲀高效生态养殖模式,开展了两种养殖模式(模式Ⅰ:暗纹东方鲀、南美白对虾和蕹菜立体种养模式,模式Ⅱ:暗纹东方鲀传统单养模式)的养殖对比试验,通过定期测量各阶段鱼的体长、体质量等生长指标,分析比较两种模式下暗纹东方鲀的生长规律和差异.结果表明:两种养殖模式下,暗纹东方鲀体长与体质量均呈良好的幂函数增长相关(W...     

对虾养殖计算机管理系统

采用现代化方法管理对虾养殖势在必行。对虾养殖计算机管理信息系统是根据对虾育苗规范和养成技术规范，按照软件开发规范设计完成，操作简单，安全可靠，具有数据录入，数据分析，统计查询，自动打印报表，数据维护等功能，可大大提高对虾养殖工作效率和管理质量，为有效遏制对虾疾病的暴发流行及时提供信息。     

浙江近海贝类养殖及其碳汇强度研究

统计、分析了浙江近10年来（2004-2013）近海贝类养殖的产量、结构、碳汇强度及其在全国所占比例。浙江近海贝类养殖年均总产量为68．46万t,主要贝类所占比例为蛏35．75％、牡蛎18．33％、蚶17．77％。全国年均总产量为1100．47万t,主要贝类所占比例为牡蛎33．99％、蛤29．65％、扇贝11．28％。浙江近海贝类养殖总产量占全国总产量的比例只有6．26％,但蚶产量占全国的40．45％,蛏占全国的34．65％。近10年,浙江贝类年均固碳量为6．29万t,全国年均固碳量为95．97万t,占全国年均固碳量的6．55％。浙江贝类固碳量整体呈现先下降后上升趋势,蛏在各种贝类中年均固碳量最高达2．29万t,其次是蚶1．14万t、牡蛎0．99万t。     

基于氮和磷平衡的负责任养殖模式下的养殖海区规划

以氮（N）和磷（P）2种重要营养盐为研究对象,提出负责任养殖概念,建立了基于负责任养殖模式下的鱼、藻复合养殖海区的规划模型。这一模式下仅考虑人工养殖行为,饲料作为养殖海区唯一的营养盐输入途径,鱼类和经济藻类作为营养盐输出途径,不考虑海水交换、自然海区藻类营养盐吸收、野生鱼类残饵摄食和生物降解等因素引起的营养盐吸收和转化过程。研究表明,鱼、藻复合养殖模式可以实现负责任养殖行为,但鱼类和藻类养殖规模比例悬殊,藻类羊栖菜（Sargassum fusiform e）和鱼类大黄鱼（Pseudosciaena crocea）的养殖面积比约为95：1,生物量比值约为30：1。单纯采用经济藻类养殖作为养殖海区营养盐平衡手段效果有限,可以考虑增加贝类养殖,加强海区营养盐转移功能。     

纤细角毛藻种群增长最适培养因子研究

集中开展了海洋生物饵料纤细角毛藻的单种最适培养因子研究.结果表明,纤细角毛藻的最适生长条件即最适盐度为30 g/L、pH 8,最佳扩群温度是25℃;而营养因子则以N/P为首要条件,研究发现在8:1的N/P比下纤细角毛藻繁殖与生长为最佳.     

大港湾贝类养殖容量的评价

应用统计分析法估算了大港湾贝类的适宜养殖面积,同时采用Tait模式和营养动态模式估算贝类自然生产力,根据调查潮间带非养殖区底栖软体动物、吊养区非养殖滤食性附着动物及浅海底栖软体动物的现存量计算贝类可养殖量,估算结果适养面积为346．67hm^2,贝类自然年生产力为31024t和29829t,海区滤食性软体动物现存量7731t,养殖容量为23293t和22098t。1996年后的实际养殖面积和养殖量已超过了估算的适养面积和养殖容量。     

长江流域2种水产养殖模式的生命周期环境影响评价

本研究以长江流域内的池塘养殖和稻渔综合种养2种水产养殖模式为对象,应用生命周期评价方法,分析2种养殖模式对能源消耗(EU)、全球变暖潜势(GWP)、酸化潜势(AP)、富营养化潜势(EP)以及水资源消耗(WU)5种环境指标的影响,并探究2种主要输入因子(饲料和电力供应)和养殖过程对各环境指标的影响,从而评价2种养殖模式对环境影响的差异.生命周期评价结果标准化处理和加权评估显示,稻渔综合种养模式的WU、EP、GWP、AP和EU值分别为11.650、0.770、0.141、0.096和0.003,总环境影响指数(TEII)为12.660;池塘养殖模式的WU、EP、GWP、AP和EU值分别为31.453、1.187、0.210、0.174和0.007,TEII为33.031.与稻渔综合种养模式相比,池塘养殖模式的各项环境指标均较高.对环境影响的贡献率分析表明,饲料供应对EU、GWP和AP的贡献率最高,EP主要受饲料供应和养殖过程的共同影响,而WU主要集中在养殖过程中,电力供应主要影响EU、GWP和AP.生命周期评价的结果表明,与池塘养殖模式相比,稻渔综合种养模式显示出更友好的环境效益,在我国长江流域具有较大的发展空间.2种养殖模式的贡献率分析表明,改进饲料生产工艺、建立精准投喂技术、应用先进的尾水处理技术和适当提高养殖密度是我国长江流域水产养殖环境友好生产的关键.     

Economic analysis of monosex culture of giant freshwater prawn (Macrobrachium rosenbergii De Man): a case study

All‐male monosex culture of Macrobrachium rosenbergii (De Man) has emerged as a popular practice in India, especially in the state of Andhra Pradesh. A study was conducted to compare the economics of all‐male, mixed and all‐female culture in 15 adjacent, rectangular ponds of 4000 m² each by stocking juveniles previously reared in a nursery for 60 days. The experiment was conducted using a completely randomized design with three treatments; T₁ (all male), T₂ (mixed) and T₃ (all female), and five replicates for a period of 5 months after the nursery phase. Statistical analysis showed highly significant (P<0.01) differences among the three types of culture. The cost of production was estimated and the economic feasibility of the culture methods was evaluated by cost‐return and partial budgeting analysis. The average weight, productivity and specific growth rate were the highest for all male culture, being 80.92±2.41 g, 1532 kg ha^?1 and 1.97±0.02 respectively. All‐female culture registered significantly higher survival (89.16±0.77%) and the best apparent feed conversion ratio of 1.26±0.02. The economic analysis revealed that all‐male monosex culture of M. rosenbergii was 63.13% and 60.20% more profitable than mixed and all‐female cultures respectively.