工厂化水产养殖中的增氧技术

工厂化水产养殖密度大、水和土地资源利用率高、水质可净化而污染少,是应用工业化方式进行水产养殖的生产模式。高效合理的增氧方式可有效增加工厂化养殖中设施与设备的效能,提高生产效率,是工厂化水产养殖的关键技术之一。本文针对水产养殖发展的新变化、新特点,论述了国内外增氧装备的结构特点、增氧方式和效果,分析了增氧技术在发展过程中存在的问题,探讨了增氧技术在工厂化水产养殖中的应用方法和创新技术的发展趋势,为进一步提高增氧技术提供参考。     

我国鲆鲽类循环水养殖系统的研制和运行现状

全封闭式海水循环养殖系统,是当前国际上先进养殖模式的代表,也是未来养殖产业发展的重要方向,备受世界关注。我国最早走上工厂化养殖道路的海水鱼类是鲆鲽类,现正由开放式向封闭式循环水养殖方向迈进,目前各项技术与工艺已经取得了长足进步。但是,根据对国内循环水系统装备的研制及其运行情况的跟踪调查,发现循环水处理的核心部分存在着稳定性、可靠性、经济性等问题急待研究解决。本文在分析循环系统主要配套装备和工艺参数的基础上,结合几家典型养殖企业的运行特点进行了分类剖析,针对现有装备和系统中发现的几个关键问题,提出了改进、提高的对策,可为今后鲆鲽类全循环养殖系统的升级、定型和走向国产化提供借鉴。     

工厂化循环水养殖系统CO2脱除工艺的研究进展

循环水养殖是未来水产养殖的主要发展方向之一，系统中CO₂的过度富集会影响生物滤器过滤效率和养殖对象生长发育，因此CO₂的高效脱除是整个循环水养殖系统中的关键技术之一。中国循环水养殖产业在30多年的发展过程中，各项CO₂脱除技术日渐成熟。文章围绕着目前国内外工厂化循环水养殖系统的应用现状，介绍了循环水系统中CO₂的来源、危害以及脱除的基本原理，综述了气体交换法、化学法和生态法3种CO₂脱除工艺的特点以及国内外研究进展，比较了各类脱除技术的优点，针对CO₂脱除主要存在的方法单一、主要设施占据空间大、成本高等问题，提出了多种脱除工艺并用、运行设备系统集约化、优化脱除过程及装备智能化等未来发展对策。本研究旨在为未来工厂化循环水养殖CO₂高效脱除技术工艺的优化与专用装备的研制提供参考。     

《渔业现代化》2015年征订启事

<正>《渔业现代化》杂志创刊于1973年,由农业部主管,中国水产科学研究院渔业机械仪器研究所主办。本刊以水产养殖工程和渔业装备为专业特色,重点报道渔业水体净化技术、工厂化循环水养殖系统、池塘生态养殖工程,以及各类新型渔业机械及其应用。本刊为中文核心期刊,联合国《水科学和渔业文摘》(ASFA)收录期刊。主要刊载内容:渔业水体净化,工厂化循环水养殖技术与设备,池塘生态与健康养殖,水产品加工与综合利用,饲料与营养,渔业资源与环境,渔业装备开发与应用,海洋渔业工程,渔业     

全封闭工厂化循环水微波消毒养殖系统的组成及运行

<正>随着我国海水鱼类养殖的发展和对渔业水域环境保护意识的加强,粗放型的养殖模式将逐渐被低污染、集约化的工厂化封闭式循环水养殖模式所取代。作者围绕封闭式工厂化循环水养殖系统的设备、工艺、管理技术等先后多次进行讨论、调研,走访循环水养殖以及废水处理企业与小型试验相结合,经过多方论证确定了一套封闭式工厂化养殖系统水处理工艺,通过首次引入微波消毒设备,成功建成一套封闭式工厂化循环水微波消     

浅议工厂化养殖中的节能减排措施(一)

在一些发达国家,工厂化养鱼被认为是水产领域的一种先进模式。工厂化养鱼设施、技术日趋普及化、智能化和产业化。能代表工厂化养殖发展方向的,主要有两大方面:一是养殖工艺和设施的改进,包括养殖设备、仪器的自动化、智能化和养殖设施向节约型、环保型的改进;另一方面是养殖品种的改良,包括养殖品种数量的增多和养殖品种质量的提高。     

中国水产养殖装备发展现状

水产养殖是我国渔业的最重要组成部分,水产养殖机械装备是现代水产养殖业发展的重要标志,绿色、高效的现代化水产养殖产业结构升级对水产养殖装备提出了更高的要求,基于装备与信息技术协同的智慧水产养殖成为现代渔业发展的新趋势。本文围绕池塘、工厂化、网箱、筏式以及底播养殖等我国主要养殖方式,梳理了当前水产养殖中常用的机械化装备和技术,并从环境监测、养殖对象感知、智能投喂、分级计数和养殖机器人等方向分析了我国水产养殖智能装备技术的研究进展,指出了制约我国水产养殖智能装备发展的关键问题。为实现我国从水产养殖大国向强国转变,融合机械装备和智能技术等两个领域的前沿技术,提出了“机械化、自动化、智能化并举”的水产养殖智能装备发展新思路。     

工厂化循环水养殖亚洲龙鱼（金龙鱼）初探

本试验利用工厂化循环水系统开展亚洲龙鱼(金龙鱼)成鱼的集约化试验养殖,对亚洲龙鱼在工厂化循环水模式下的饲养方式、水质调节、疾病防控、日常管理等养殖技术要点进行总结,为今后亚洲龙鱼的工厂化大规模养殖生产提供技术参考,同时对我国休闲渔业发展起到促进作用。     

海水工厂化养殖虹鳟营养品质分析与评价

为更好地了解海水工厂化养殖虹鳟(Oncorhynchus mykiss)肌肉组织的营养成分和品质,采用国标等方法,分别对海水工厂化养殖和淡水养殖虹鳟肌肉组织的各项营养成分进行了分析和评价。结果显示:海水工厂化养殖虹鳟肌肉组织的蛋白质含量、氨基酸营养水平和脂肪酸含量均低于淡水养殖虹鳟。海水工厂化养殖虹鳟肌肉组织的氨基酸营养价值和化学平均得分分别为0.82、0.62,低于淡水养殖虹鳟(1.04、0.78)。海水工厂化养殖虹鳟肌肉组织的饱和脂肪酸和不饱和脂肪酸的含量(3.83g/100g、12.60g/100g)低于淡水养殖虹鳟(4.07g/100g、12.79g/100g)。     

论节能型工厂化循环水养殖的精准化

渔业实施精准化战略,是我国现代渔业向工业化发展的必由之路.工厂化循环水养殖作为一种环境友好型和资源节约型先进养殖模式的典范,实施精准化是推动水产养殖产业向工业化迈进的加速器和重要标志,有积极的示范作用.本文论节能型工厂化循环水养殖的精准化,从养殖技术与设施装备,以及集成的各个环节和不同角度进行了可精准化的分析,对其实现途径作了较全面的阐述.     

水产养殖中鱼类投喂策略研究综述

水产养殖中的饲料成本占养殖总成本的比例较大,有效的投喂策略是减少水产养殖生产成本的重要途径,投饲装备投喂过程中,既要满足鱼群生长的营养需求,也要避免过多投饲,从而降低对环境的污染。当前国内水产养殖投饲装备智能化水平较低,投饲策略主要依据人工经验定量投饲,每一次喂料的偏差累积影响整期渔获经济效益。因此,科学的投喂策略能有效减少养殖成本,提高养殖效益。重点介绍了基于人工经验及生物能流的鱼群生长摄食模型、基于机器视觉及机器声学感知鱼群摄食活动的技术手段和智能投喂控制系统的发展状况,并提出投喂策略的具体实现方法。本研究可为水产养殖投饲装备从自动化升级到智能化提供参考。     

Response of different benthic habitats to off‐shore fish cages

Off‐shore fish farming can increase the organic load of nearby coastal marine ecosystems due to the deposition of fish food and faeces on seabeds. Seagrass meadows are particularly affected by aquaculture activities but there are few empirical data showing differential effects of the same farming activity on multiple habitat types. Here, we assessed over a 2‐year period whether macrofaunal assemblages inhabiting sandy bare seabeds and Cymodocea nodosa meadows varied in their macrofaunal community structure to the fish farming activities. We observed high spatial and temporal variability in macrofauna composition and dynamics among seabed habitats and a limited impact of fish cages in their area of influence as compared with control areas. Seagrass meadows showed a higher abundance in macrofauna communities than sandy bare bottoms. Local marine currents could partially explain some results because of their influence on grain size composition. Differences in grain size resulted in higher abundances of the tanaid Apseudes talpa beneath fish cages and the absence of the sensitive amphipod Ampelisca brevicornis. Differences of resilience of seabeds (seagrass meadows and sandy bare bottoms) should be taken into account for environmental monitoring studies of off‐shore fish cages. Our results suggest that hydrodynamics are a key factor to determine buffer areas between fish cages and seagrass meadows.     

Mortality and fish welfare

Mortality has received insufficient attention as a fish welfare topic. Here, we aim to prompt fish farming stakeholders to discuss fish mortalities in relation to welfare. Mortality in farmed fish populations is due to a variety of biotic and abiotic causes, although it is often difficult to differentiate between underlying and immediate causes of mortality. Most mortality appears to occur during episodes associated with disease outbreaks and critical periods (in development or production). Most causes of mortality can be assumed to be associated with suffering prior to death. As mortality rates in farmed fish populations are suspected to rank amongst the highest in commonly farmed vertebrate species, mortality should be a principal fish welfare issue. Long-term mortality rates can be used as a retrospective welfare performance indicator and short-term mortality rates as an operational welfare indicator. Scrutiny of mortality records and determining causes of death will enable action to be taken to avoid further preventable mortality. The welfare performance of fish farms should only be judged on levels of predictable and preventable mortality. Fish farmers will already be monitoring mortality due to commercial and legal requirements. As profitability in fish farming is directly linked to survival, confronting mortality should ultimately benefit both fish and farmers.     

Socio-economic factors critical for intensification of fish farming technology. A case of selected villages in Morogoro and Dar es Salaam regions,Tanzania

Intensification of farm technologies has shown high potential in improving farm production and enhancing rural food and income security. Intensification, however, is commodity-specific with high-value crops intensively produced. Farmed fish is one of the high-value crops introduced in the study area to meet the above ends. The problem, however, is that the level of intensifying fish farming technology has been very low leading to discouraging results. A study was conducted in Morogoro and Dar es Salaam Regions, Tanzania, to identify socio-economic factors that influence the intensification of fish farming technology. Data were collected from 234 respondents randomly sampled from 25 selected villages and were analyzed using multinomial logistic regression model. Results indicated that age, extension education, profitability, marketability, risk, palatability and easiness to obtain farmed fish were significant in explaining the intensification of fish farming technology. Three recommendations emerge from this finding. First, there is need to provide extension education to the practicing farmers on various aspects of fish farming. The probability of intensifying fish farming is higher for knowledgeable farmers. Second, technology developers should strive to reduce the risk of farming fish and improve the profitability and marketability of farmed fish. Finally, any analysis focusing on intensification of a fish farming technology should not confine itself to agronomic and socio-economic characteristics but should also encompass food characteristics of the technology. Food variables such as palatability and easiness to obtain farmed fish have been shown to influence the intensification of fish farming technology.     

Monitoring the environmental impacts and consent compliance of freshwater fish farms

Strategies for monitoring the chemical and biological impacts of freshwater land-based and cage fish farms in the West of Scotland are described and the results of monitoring are presented. The compliance of land-based farms with discharge consents is discussed. The impact of fish farming on receiving water chemistry was found to be limited, but effects on benthic invertebrate communities in both running waters and lochs were more readily detectable, although generally localized in the immediate vicinity of the farm. The benthic fauna of a stream receiving wastes from a land-based farm recovered within 19 months of the discharge ceasing. At a vacated cage site in a loch, severe impact on the sediments was still evident after more than 3 years. Problems in monitoring for consent compliance are discussed and the need for closer liaison between the industry and regulatory bodies is emphasized.     

温流水养鱼系统对电厂冷却水影响的研究

对具有水处理设施的温流水养鱼系统的供水、养鱼水及回水进行了水质分析，结果：ＰＨ值、ＤＯ、ＡＬＫ、Ｃａ＾２＋和水温依次下降，经过集中水处理后的回水ＣＯＤ、ＢＯＤ５、ＴＨ、ＳＳ和Ｍｇ＾２＋的值有所下降，ＢＯＤ５去除率为５４．３８％，悬浮物去除率为６７．５４％；ＮＨ４＾＋－Ｎ和ＮＯ２＾－－Ｎ依次升高；电导率无明显变化；而ＮＯ３＾－－Ｎ供水略高于养鱼水，在此基础上讨论了温流水养鱼系统对电厂冷却水的正面影响     

Integration of sonar and optical camera images using deep neural network for fish monitoring

Fish monitoring in aquaculture farms is indispensable for managing the growth and health status of fish resources. However, it is unrealistic to expect humans to be able to perform monitoring at night, when standard optical cameras are generally inapplicable. Although sonar systems can be used at night, their practical applications are limited by their monochrome, low-quality images. In this paper, we describe a realistic image generation system that uses sonar and camera images recorded at night. The proposed approach is based on conditional generative adversarial networks, which learn the image-to-image translation between sonar and optical images. We tested the system in a fish tank containing thousands of sardines (Sardinops melanostictus). Images were simultaneously recorded using high-precision imaging sonar and an underwater camera. Experimental results show that the proposed model successfully generates realistic daytime images from sonar and night camera images. Our system enables nighttime monitoring using sonar and an optical camera, leading to more efficient fish farming and environmental surveillance.     

Precision biometrics data of Atlantic salmon (Salmo salar L.) in commercial grow-out sea-cages: Manual sampling and infrared diode frames compared to processing plant

One of the critical challenges that the global salmon farming industry will confront when upscaling production is accurate biomass control. Commercial salmon farming requires a significant level of certainty regarding fish count, average weight measurement, live weight distribution, and other production indicators. A reliable control system for assessing the biomass of farmed Atlantic salmon is essential for sustainable and cost-effective precision aquaculture. A study was done in four production sea-cages in a Chilean Atlantic salmon marine grow-out farm to estimate the average weight and frequency distribution utilizing the Vaki Biomassdaily® diode frames as an alternate technology to manual weight measurement. From post-smolt reception to fish harvest, diode frames were put in each sea-cage in a secure position for 15 months. There were no significant changes in length or average weight between manual sampling and frame estimate. The mean degree of accuracy for the average weight estimation was 98.83 % for the frames utilized in the four sea cages. The diode frames also achieved a high degree of precision in predicting the frequency distribution of fish. There were no statistically significant variations between the distribution variances of the diode frame measurements and the distribution variances of the fish received at the fish processing facility (FPF). The maximum difference between the average weight calculated by the frames and the average weight of the fish received in the processing facility was 2.4 %, with 99.66 % being the highest accuracy with only 19 g of difference. We determined that diode frames might replace manual weight assessments with greater reliability for growth monitoring and production management. To assure the optimal performance of the diode frames in terms of accuracy and precision for future commercial-scale validations in the salmon farming business, the development of a standard best practice manual is necessary.     

Protection, immune response and side-effects in European whitefish (Coregonus lavaretus L.) vaccinated against vibriosis and furunculosis

As indicated by market demand and cultivation prospects, the whitefish (Coregonus lavaretus L.) has the potential to become an important alternative to rainbow trout in fish farming in Finland. The fish processing industry has called for a fish species having non-pigmented flesh, and there is a long tradition of whitefish farming for stocking purposes in Finland. However, cultivation in net cages in the brackish water of the coastal area exposes fish to vibriosis (Listonella (Vibrio) anguillarum) and furunculosis (Aeromonas salmonicida salmonicida). Hence, profitable whitefish farming requires the efficient control of both of these diseases. The efficacy of vaccination (Apoject 1800®) was studied in the laboratory using challenge tests and by monitoring specific antibody production (ELISA) and the blood leucocyte pattern. The fish (22 g) were vaccinated at 15°C and the immunity developed during 8 weeks prior to challenge with vibriosis (1.8×10⁵ cfu) and 12 weeks prior to challenge with furunculosis (4.9×10² cfu). The challenge was performed by i.p. injection. Side-effects around the injection site were studied 16 weeks post-vaccination. The immune system of the whitefish responded well and vaccination gave good protection against vibriosis and furunculosis. The RPS was 100% following the Vibrio challenge and 99% following the Aeromonas challenge. The antibody levels continued increasing in the vaccinated group throughout the study period. Lymphocyte and neutrophil counts were elevated in vaccinated compared to non-vaccinated fish at 8 weeks post-vaccination, but not after 16 weeks. Vaccination produced weak adhesions around the injection site in 42% and minor pigmentation in 9% of the 65 fish examined.     

Examination of net volume reduction of gravity-type open-net fish cages under sea currents

Owing to heavy criticisms of nearshore fish farming for causing environmental pollution and encroaching on sea space used for shipping, boating, recreational sea activities and marine eco-tourism, offshore fish farming has now being seriously considered. Moreover an offshore site provides more pristine water and greater space for increased fish production. However, offshore fish farming poses challenges such as a more energetic sea environment. A higher sea current can lead to large deformation of fish net and hence a net volume reduction which compromises fish welfare. With the view to identifying the effects of various important parameters on net volume reduction of a gravity-type open-net fish cage, this paper adopts a mass-spring model for the dynamic analysis of current-induced net deformations of cylindrical fish nets with discrete weights hanging at the bottom edge of the nets. In this model, the net mesh comprises knot nodes and bar nodes connected by tension-only massless springs. The spring stiffness is determined from the net bar diameters and material properties. The current-induced loads are applied to each node and calculated based on Morrison’s equation. The governing equation system for nodal motions can be established according to Newton’s second law, and solved by using the Runge-Kutta method for the real-time net deformations. The effects of net string reinforcements, weight distributions and net shapes on the net volume reduction are studied with the view to shed insights into how one may improve fish cage designs to effectively mitigate net deformation under high sea current speeds in offshore fish farming sites.