The effectiveness of a commercial microbial product in poorly prepared tiger shrimp, Penaeus monodon (Fabricius), ponds

The efficacy of a commercial microbial product was tested in commercial tiger shrimp, Penaeus monodon (Fabricius), ponds for one culture period in Kuala Selangor, Malaysia. Four ponds with replicates for treatment and control were used. The pond bottom was dried but the organic sludge was not removed as normally practised in pond preparation. The ponds were stocked with 15 post‐larvae at the rate of 31.m^?2. Physical, chemical and biological parameters of the pond were analysed every 2 weeks during the culture period. Water quality parameters remained within the optimum range for shrimp culture except for ammonia‐nitrogen being significantly higher in control ponds and silica in treated ponds. Benthic organisms were not found in any of the ponds. The average counts of different bacteria were not significantly higher in treated ponds than control. Because of poor health, the shrimp were harvested earlier (72 days) than the usual 120 days. An average of 875.60 ± 67.00 kg shrimp ha^?1 was obtained in treated ponds with a feed conversion ratio (FCR) of 1.57 ± 0.10 and survival rate of 42.35 ± 5.37% compared with 719.50 ± 130.94 kg shrimp ha^?1, 2.99 ± 0.70 and 21.25 ± 3.26%, respectively, in control ponds. Neither the microbial product nor the frequent water exchange was effective in overcoming the problems caused by the poor pond bottom.     

Influence of pond fertilization and feeding rate on growth performance, economic returns and water quality in a small-scale cage-cum-pond integrated system for production of Nile tilapia (Oreochromis niloticus L.)

The effects of pond fertilization and feeding rate on growth, economic returns and water quality were investigated to develop a low‐cost cage‐cum‐pond integrated system for production of Oreochromis niloticus (L.). Hand‐sexed male fingerlings averaging 19±0.39 and 32±0.69 g were stocked in cages and open ponds at 150 fish cage^?1 and 2 fish m^?2 respectively. Fish were cultured for 114 days in five triplicate treatments. Cages were installed into ponds and caged fish were fed a 24% protein diet at 3% (T1) and 6% (T2) body weight day^?1 (BWD) without pond fertilization, and 6% BWD with pond fertilization (T3). The open water in the fourth treatment (T4) was not stocked but contained caged fish, which were fed 6% BWD for the first 57 days followed by 3% BWD for the remaining period. Ponds in the control (T5) had no cages and were neither fertilized nor open‐pond fish fed. Feeding rate and pond fertilization significantly (P<0.05) affected fish growth, profitability and water quality among treatments. Fish growth, feed utilization, fish yield, water quality and profits were significantly (P<0.05) better in T3 than the other treatments. It was concluded that fish production and economic returns were optimized at 6% BWD in fertilized ponds.     

海水池塘养殖模式优化：概念、原理与方法

随着海洋渔业资源衰退和人类社会对水产品需求的持续增长,海水养殖规模逐年扩大,养殖生产对环境的影响也日益严重[1-6]。现已确认海水鱼虾类养殖是造成海洋沿岸带水域富营养化的重要污染源之一[5-8],这一严峻现实要求今后在发展海水养殖产业时不仅需要宏观上对养殖区域和养     

对虾白斑病围栏封闭预防技术

“对虾白斑病的围栏封闭预防技术”是一项针对沿海低位池塘、以切断传染病源为主旨、以设置防蟹围栏为特色的对虾白斑病综合预防技术。其主要措施为：首先在贮水(兼水处理)池和养殖池周围设置防蟹围栏，将该等池塘封闭起来，使杂蟹不会从陆地侵入池内；然后通过60目滤网进水，并用敌百虫或敌杀死处理上述两种池塘，杀灭以蟹类为主的一切甲壳动物；解毒后，放养经检测不带白斑症病毒的虾苗；采取封闭式养殖，养殖期中只向养殖池加水以补充渗漏和蒸发的水损失；加水时，先将海水在贮水池中用药物处理，杀灭其中的传染该病的媒介生物(主要是桡足类)，药物解毒后再注入养殖池。此外，作为辅助措施，在养殖期中从多方面尽量保证虾池中有一个良好的生态环境。该技术已经过预备研究、实验研究和扩大试验等阶段，均证明效果良好。已扩大试验了近33．33hm^2(其中实际养虾池约17．33hm^2)，成功率达96％左右。     

Effect of organic fertilizer on plankton primary productivity in fish ponds

The effect of cattle organic fertilizer on plankton primary production and related variables was tested in six Bulgarian fish ponds situated close to the town of Plovdiv in Bulgaria. At the beginning of the experiment (16th of May 2004, about 10 days after filling with water) a suppression of plankton metabolism was observed and after that the ponds treated with manure demonstrated significantly higher productivity than the controls, especially during the transition to the autumn season when the water column was more regularly mixed. The other measured variables (Secchi disk readings, plankton chlorophyll-a and respiration, assimilation number per unit chlorophyll-a) did not show significant differences between the treated and control ponds.     

The potential of temporary shelters to increase survival of the endangered Mexican axolotl

1. Amphibian populations worldwide are in decline. Proactive conservation techniques such as translocations into created and restored wetlands have gained popularity in recent years but may fail owing to high predation and low environmental adaptability.
2. The Mexican axolotl (Ambystoma mexicanum), affected by rapid urbanization, is now possibly extinct in the wild despite millions living in captivity throughout the world.
3. The aim of this study was to explore whether ponds from an artificial wetland can function as temporary shelters for a viable population of axolotls that could be re-introduced into their native ecosystem in Xochimilco once it is restored.
4. Egg-laying and hatching of 11 unique axolotl pairs placed into reproductive enclosures and larval survival to 7 weeks and up to 12 months were examined. Physicochemical and biological parameters were estimated and compared among ponds.
5. The results from this study are encouraging as they suggest that two ponds have adequate conditions for axolotls to reproduce and for larvae and juveniles to survive.

     

“Summer syndrome” in Litopenaeus stylirostris grow out ponds in New Caledonia: Zootechnical and environmental factors

The “Summer Syndrome”, a septicemic vibriosis caused by Vibrio nigripulchritudo, is responsible for one of the two main seasonal mortalities which affect shrimp aquaculture in New Caledonia. It was identified for the first time in December 1997 in an intensive shrimp farm (called farm DF) and has been enzootic ever since. The “Summer syndrome” affects shrimp during warm-season growout. Although the geographic area concerned is limited, it is a potential threat for the industry in that the disease could spread. Analysis of grow out data from 1991 to 2002 in this farm was carried out in order to characterize the disease and the environmental conditions in relation to mortality. Results of farm DF were compared to data from farms not affected by the disease (called farms HC). The “Summer syndrome” occurs during the warm season which is characterized by an increase in water temperature and sunny duration. This disease is characterized by simultaneously highest densities and weakest drying duration between crops in the farms studied. Between 1991 and 2002, the increase of feed input and nitrogen rate in feed has led to a significant increase of the growth rate over the years in farm DF. At the same time, water management has not changed and has induced an increase in environmental waste production. In consequence, an early eutrophication of water is observed, which is concomitant with the beginning of the mortality outbreaks. This could play a role by inducing directly or indirectly a stress for shrimp and/or a growth and/or virulence factors of the pathogen.     

密植浒苔对冬季露天池塘池底水温、酸碱度和溶解氧的影响效应

借助环境数据实时采集装置,于2014年1月5日至1月22日连续开展了冬季露天池塘培植浒苔对池底水温、酸碱度和溶解氧的实时监测工作。结果表明：（1）密植浒苔可在不改变池底水温峰值期时辰数的基础上,提前1个时辰到达峰值,在不影响到达谷底时辰的同时,使低谷期缩短了1个时辰,并由此延长了水温由峰到谷的转换时长;（2）密植浒苔可保持池底p H值的基本稳定,并在不改变池底p H值时段变化节律的基础上,使日均p H值由9.3下调至8.6;（3）密植浒苔在对池底DO值的时序变化影响上与池底水温相仿,并使日均DO值由10.61mg/L下调至6.80mg/L。     

Taxonomic and functional macroinvertebrate diversity of high-altitude ponds in the Macun Cirque,Switzerland

1. Global environmental change is threatening freshwater biodiversity with ecological impacts predicted to be particularly severe in high-altitude regions. Despite this, an ecological understanding of high-altitude pond networks remains patchy, with only limited knowledge of the environmental and spatial predictors of taxonomic and functional diversity. Moreover, previous studies of pond ecosystems have focused primarily on taxonomic richness and largely overlooked functional diversity.
2. This study examined the influence of local environmental and spatial factors on taxonomic and functional α and β diversity (including the turnover and nestedness-resultant components) of 17 high-altitude (~2,500 m above sea level) pond macroinvertebrate communities, in the Macun Cirque, Switzerland.
3. Spatial processes (pond connectivity) were important drivers for taxonomic α diversity, while local environmental variables (pond permanence and surface area) were important determinants of functional α diversity. Species turnover was the most important component of β diversity for taxonomic composition, and functional composition demonstrated a nested spatial pattern.
4. Variation in taxonomic and functional composition (and the turnover and nestedness components of β diversity) were determined by local environmental variables despite the limited environmental gradients within the pond network. No significant effects of spatial variables on community composition were recorded for either facet of diversity, indicating that compositional variation was determined at a local scale. Water temperature, depth and pond permanence were consistently the most important measured drivers of diversity.
5. Given the importance of both spatial and environmental variables in structuring taxonomic and functional diversity, landscape-scale conservation and management activities that aim to improve or protect high-altitude freshwater biodiversity should focus on maintaining connectivity among ponds and environmental heterogeneity, particularly pond surface area, water depth, and hydroperiod. Understanding the mechanisms driving taxonomic and functional diversity will be critically important for the management and conservation of macroinvertebrate communities in high-altitude pond networks in the face of climatic warming.

     

盐碱地池塘配置网箱养鱼试验

在盐碱地一个面积为2871m^2的鱼池中，配置4个网箱．分别放养罗非鱼、淡水白鲳和鲤，箱外放养鲢、草鱼和鲤。试验结果：罗非鱼箱(20m^2)出鱼525kg．平均单产26．3kg／m^2,淡水白鲳箱(12m^2)出鱼400kg,平均单产33.3kg／m^2,鲤鱼箱两个(各12m^2)分别出鱼488．5kg和522kg，平均单产为40．7kg／m^2和43．5kg／m^2。箱外出鲢516kg,草鱼130kg，鲤1125kg。总计全池出鱼3706．5kg，亩产鱼862kg，每亩纯盈利2173．85元。试验证明：池塘配置网箱养鱼．可同池主养几种鱼，起捕容易，管理方便。