Energy use in controlled temperature marine aquaculture

Temperature control offers benefits in land‐based marine aquaculture: stock growth rates may be enhanced by heating in winter; mortality rates in summer may be reduced by cooling. However, if the plant is not well designed, temperature control may create very large energy demands. This paper describes the application of temperature control in abalone aquaculture in New Zealand, with a focus on energy considerations in plant design. An abalone farm using a semi‐closed water conditioning system is used as a case study for which an energy model, based on a heat pump system, is developed. The model is used to determine the impact of plant design and tank conditions on the economics of the operation. Copyright © 2002 John Wiley & Sons, Ltd.     

基于遥感案例推理的海岸带养殖信息提取

目前基于目视解释或光谱分类的养殖信息提取效率低,难以克服由于地物混杂带来的“椒盐”噪声现象且难以融合地学知识。针对养殖信息提取中存在的问题,首先在分析现有养殖信息提取方法和案例推理CBR(Case\|Based Reasoning)用于遥感图像处理的基础上,提出基于遥感案例推理的海岸带养殖信息提取的研究思路;其次,结合养殖区域的空间特征和属性特征,构建案例的表达模型以及CBR相似性推理模型;最后,对不属于案例构建区的粤西沙田镇进行养殖信息提取的CBR实验,精度达到84.56%。对比CBR方法和传统监督分类方法可知,CBR方法是实现海岸带养殖信息快速准确提取的一种有效手段。     

Rancidity development during the chilled storage of farmed Coho salmon (Oncorhynchus kisutch)

Coho salmon (Oncorhynchus kisutch) is a fatty fish species whose farming production has greatly increased in recent years. Lipid damage produced during Coho salmon chilled storage was studied for up to 24 d. Lipid hydrolysis (free fatty acids, FFA) and oxidation (conjugated dienes; peroxide value, PV; thiobarbituric acid index, TBA‐i; fluorescent compounds formation, FR; browning development) were determined and compared to lipid composition (polyene index, PI; astaxanthin, AX) changes and sensory assessment (rancid odour development) results. Most lipid damage indices developed slowly during storage; thus, values obtained for FFA, PV, TBA‐i and FR were in all cases under 1.5 g/100 g, 4.0 meq oxygen/kg lipid, 0.40 mg malondialdehyde/kg muscle and 0.40, respectively. Odour assessment showed a significant (p <0.05) rancidity development at day 10, when compared to starting fish material; then, non‐acceptable values were obtained at days 19 and 24. The PI analysis showed not many differences during the storage time, with the lowest mean value at day 19. AX analysis indicated a relatively high content in the white muscle, which was maintained till the end of the experiment. A low oxidation development is concluded for Coho salmon lipids when compared to other fatty fish species under the same chilling conditions. AX was found to contribute to the oxidation stability of Coho salmon lipids, due to its free radical scavenger properties.     

Modeling impact of culture facilities on hydrodynamics and solute transport in marine aquaculture waters of North Yellow Sea

An increasing number of marine aquaculture facilities have been placed in shallow bays and open sea, which might significantly affect hydrodynamic and solute transport processes in marine aquaculture waters. In this study, a coupled hydrodynamic and solute transport model was developed with high-resolution schemes in marine aquaculture waters based on depth-averaged shallow water equations. A new expression of drag force was incorporated into the momentum equations to express the resistance of suspended culture cages. The coupled model was used to simulate the effect of suspended structures on tidal currents and the movement of a contaminant cloud in the marine aquaculture of the North Yellow Sea, China. The simulation results showed a low-velocity area appearing inside the aquaculture cage area, with a maximum reduction rate of velocity close to 45% under high-density culture. The results also showed that tidal currents were sensitive to the density of suspended cages, the length of cages, and the drag coefficients of cages. The transport processes of pollutants inside aquaculture facilities were inhibited away from the vicinity of the culture cage area because of the diminished tidal currents. Therefore, the suspended cages significantly affected the transport processes of pollutants in the coastal aquaculture waters. Furthermore, the reduced horizontal velocity significantly decreased the food supply for the aquaculture areas from the surrounding sea.     

基于多智能体协同的无线传感网络水产养殖监控系统

基于现有监控系统在自学习能力和监控范围方面的局限,将多智能体技术引入到规模化水产养殖监控系统中,提出了一种基于多智能体协同的无线传感网络水产养殖监控系统。系统由信息采集智能体、信息汇聚智能体、环境调节智能体、现场监控智能体和远程监控智能体组成。通过多智能体间的协作,使系统的监控能力得以增强,便于适应多变的养殖环境。试验结果表明,系统能够根据养殖环境因子的变化对养殖环境进行调节,精度满足要求,能够适应规模化水产养殖环境监控的需要。     

乌江渡水电站水库网箱养殖对环境的影响及对策措施研究

文章从对水体富营养化的影响、对水质的影响、对水生生物的影响、对底质的影响、对库湾水文条件的影响5个方面分析了乌江渡水电站水库网箱养殖对环境的影响,以及对解决这些问题的对策措施进行了介绍和探讨.     

智慧生态水产养殖系统

针对工厂化海参养殖信息化低的现状,设计并实现了具有养殖环境水质监测、养殖环境水质分析评价、水下视频观测、养殖知识普及等功能的系统.该系统经测试,水质检测准确,水下视频观测实时清晰,可以满足海参养殖的实际需要.系统的推广可以帮助养殖企业进行养殖决策,提高养殖的智能化水平.利用工业化和智能化在水产养殖业领域的纵向扩散和深度融合,来探索现代化养殖模式,提升智能技术在渔业经济发展中的贡献率.     

微生态制剂在水产养殖中的应用

主要从防治鱼病的发生及减少抗生素滥用、改良水质和防治有害蓝藻等三个方面的作用综述了微生物制剂在水产养殖中的应用现状及研究进展,分析了目前微生物制剂研究及生产中存在的问题,并对微生物制剂在水产养殖中的研究及应用发展趋势作了进一步的展望。     

水产养殖智能监控网络系统的设计与实现

为了提高水产养殖的工厂化水平,提出基于Profibus现场总线网络控制的智能监控系统。采用现场总线、PLC、传感器、计算机技术对养殖池的溶氧量、pH值、温度、水位等主要环境参数进行自动检测和控制,开发人机界面和数据库系统,实现养殖数据的实时采集、动态监测和处理。经实际应用证明,该系统运行稳定可靠,易于扩展,有效提高了水产养殖的自动化水平和产品品质。     

Non-dioxin-like PCBs: a survey on fishery and aquaculture from the Mediterranean area

A sampling campaign from 21 sites in Italy was conducted: 15 species from fishery and three species from aquaculture, for a total of 40 determinations, were considered. A careful sample preparation preceded the instrumental analysis that was carried out by means of GC–ECD and GC–MS. Good laboratory practice was achieved by the participation in proficiency tests, by the use of certified reference materials and by applying other directives recommended by international organisations. Concentrations measured in this work were compared with a TDI proposed by some international bodies: for a person weighing 70 kg one-third of the samples from fishery, when consumed, lead to exceed this TDI if the average fish daily consumption per capita is considered. Based on the data obtained here some hypotheses on environmental spreading and influence of PCBs on human health are made. Some suggestions about the preparation of fish for consumption are also given.