网箱真空吸鱼泵试验中的技术问题研究

随着网箱养殖业的发展，渔获量的增加和销售流通环节的需要，用于活鱼起捕的吸鱼泵、真空活鱼起捕机，作为网箱养殖业的配套设备，有着极大的市场潜力和发展空间。国内外有许多科研院所都已加入到研究和开发该类产品的行列中去，其中不少国家已在实际生产中使用了不同形式的吸鱼泵。     

深水网箱养殖鱼类的分级与起捕技术

鱼类的规格分选与起捕销售是网箱养殖生产中的重要环节.以往的手工操作不仅费时、费力,而且由于鱼类转移速度缓慢以及操作过程中对鱼体的损伤和对鱼群的惊吓等,还会带来较高的死亡率.随着我国大型深水抗风浪网箱养殖的发展,这一问题日显突出.本文介绍了国外几种典型深水网箱养殖鱼类的大小分级与起捕的方法,总结我国大型深水网箱养殖鱼类分级与起捕设备的研究进展.研制的柔性格栅式分级装置不仅具有可折叠、操作方便和不损伤鱼体等特点,而且通过更换不同间隙的分离栅,可实现鱼类大小的多级分离.海上分级试验表明,经10min分级,允许逃逸的小个体鱼类的平均分离率可达90.3%;研制的真空活鱼起捕机可实现鱼类的快速转移,最大起捕个体可达1.5kg,且对鱼体无损伤,在鱼水比例为1:1的情况下,活鱼起捕量可达20t/h.     

深水网箱养殖鱼类的分级与起捕技术

鱼类的规格分选与起捕销售是网箱养殖生产中的重要环节。以往的手工操作不仅费时、费力,且由于鱼类转移速度缓慢以及操作过程中对鱼体的损伤和对鱼群的惊吓等,还会带来较高的死亡率。随着我国大型抗风浪深水网箱养殖的发展,这一问题日显突出。本文介绍了国外典型深水网箱的鱼类分级与起捕方法,并对作者自行研制的柔性格栅式分级装置和真空活鱼起捕机的设计原理和主要试验结果作了报道。     

印度南部石斑鱼钓捕与暂养技术方法

前言应印度水产养殖基金会（AQUACULTUREFOUNDATIONOFINDIA）的邀请，我曾在印度南部图提克林（Tuticorin）参加了由水科院国际合作处、香港中顺水产集团有限公司与印度SCANETAQUAEXPORTSLTD合作的“活鱼捕捞与暂养（LivFishCatchingandCulturing）”项目。该项目主要是在印度南部以延绳钓钓捕以石斑鱼为主的优质鱼类，经放气处理后，暂养在网箱中，待活鱼数量达到一个活鱼运输船的载运量，香港公司派船运回香港，活鱼上市。现将其中的部分工作情况作一介绍。一、活鱼捕捞方法1．延绳钓钓捕活鱼试验：延绳钓为印度南…     

网箱养殖翘嘴鳜试验

<正>2008年我们在江西省南城县廖坊水库进行网箱养殖翘嘴鳜的试验,重点解决了翘嘴鳜由吃活鱼驯化为吃死鱼、鱼块的关键技术难题,取得了良好的养殖效果,并进行适时起捕,投入产出比达到了1:1.95,获得了较高的经济效益。     

文丘里(Venturi)吸鱼泵研究

介绍了文丘里(Venturi)射流吸鱼泵的结构、原理及应用。文丘里吸鱼泵无叶轮,靠水射流产生负压来抽送活鱼,输送过程中活鱼无损伤,每小时输送活鱼(鱼水混合)20 t,扬程5 m,效率高,适用于深水网箱养殖。     

北方寒冷地区发展淡水网箱养鱼的定位与关键点

一、网箱养鱼发展的简要回顾据史料记载,网箱养鱼在一百多年前发源于柬埔寨。当时,渔民为了把多捕的鱼留下来,以待日后销售,就将活鱼装在大竹篓里,像喂鸡一样,经常投喂一些小杂鱼或食物残渣,结果就形成了现代网箱养鱼的雏形——笼养法。     

网箱养鱼大有可为

网箱养鱼是一项新的养殖生产方式，它具有许多独特的优越性。网箱养鱼能充分利用水体，尤其是一些大型水体；活鱼起水方便，是一个活鱼储备库，对调节市场起一定的作用，它单位水体产量较高，目前一般要比池塘养鱼高10—20倍，比水库鱼产量高200倍以上，是一项投资少见效快，收益大的养殖生产方式。     

舟山市普陀区开展深水网箱养殖初试效果显著

浙江省舟山市普陀区从挪威引进全省第一家深水网箱养殖设备，自２０００年９月２２日正式投产以来，到２００１年４月２９日全部起捕换箱或移鱼为止，历时７个月零７天。致此深水网箱第一阶段试养暂告段落。通过对该阶段深水网箱试养情况观察，养殖鱼类起捕综合检查与对照组小网箱养殖测量比较，深水网箱养鱼初步显示出优势，同时也存在一些问题。现将本阶段试养情况小结如下： 一、优势方面： １．鱼类生产快。如孙明康单位放养的美国红鱼、免状黄姑鱼、真鲷三种鱼类，其中美国红鱼９７６０尾，鱼种均重２２０９，到４月 １７日起捕检查时…     

国内外活鱼车技术发展概况

在我国历史上，早已有活鱼运输、贮存的设备和技术。如浙江、江西两省，用活鱼木夹或采取鱼咀里衔草的办法运输活鱼：广西用网箱贮鱼和运输；福建用绳子栓住大鱼在水中拖运。浙江和两广至今仍普遍使用活鱼桶、活鱼篓、活鱼船运输。近年来陆续出现了一批机动活鱼船。广东已有135吨的机动活鱼船运送活鱼出口，活鱼船用120马力水泵喷水增氧，鱼水比是1：3，水是循环使用的。     

Advances in fish harvest technologies for circular tanks

Improved equipment and husbandry practices are required to effectively grade and harvest fish in large land-based culture tanks. The objective of our work was to develop and evaluate several types of relatively inexpensive, portable, and efficient fish handling equipment to reduce the labor requirement for grading and harvesting fish from large circular culture tanks. This equipment and husbandry practices also had to provide for worker safety and minimize the stress or damage to the fish. Two techniques were developed and evaluated to remove the entire population from a large and deep circular tank, i.e. (a) purse seine and (b) carbon dioxide avoidance response. Two other techniques were developed and evaluated to remove the fish from a large (150 m³) and deep (2.44 m) circular culture tank after they had been top-graded in situ using a 3-panel clam-shell grader: (c) an airlift fish pump and hand sorting/dewatering box and (d) a sidewall drain box for hand sorting/dewatering. Some of these technologies are new, while others (such as the purse seine) have been used in other applications. Our commercial-scale evaluation of these technologies provided insight into the advantages and disadvantages of each option. With use of the clam-shell grader, the majority of the fish in the culture tank were never lifted from the water during the self-sorting process, which minimized stress, perhaps enhancing final product quality. In contrast, harvesting the tank using the purse seine and hand brailing was much more labor intensive and increased the stress on the fish, as indicated by a nearly 10-fold increase in fish mortality compared to the mortality observed when the clam-shell type crowder/grader system and an airlift fish pump or sidewall drain box were used during fish harvest. The combination of the clam-shell crowder/grader with the sidewall drain harvest box was our preferred harvest method, because of its low labor requirement, relatively low fish mortality, and rapid harvest rate. We also think that the carbon dioxide avoidance harvest technique can be used effectively, with little labor input and practically zero mortality when the entire fish population must be removed from a fish culture tank, but not during a selective harvest using in situ grading. Ultimately, the more effective technologies and practices should help fish farmers overcome scale-up issues and improve land-based fish farm profitability.     

浅海围网养殖鱼类捕捞网箱的设计与试验

为解决浅海围网设施养殖鱼类的捕捞和分级,以浮绳式围网养殖为研究对象,根据养殖围网设施的结构和大小、敷设技术和主要性能,结合围网养鱼方式和养殖生产的特点,设计并制作了一种分级捕捞网箱。网箱由框架钢筋、网衣、绳索、分级栅等构件制作而成,网箱网身呈圆柱形,顶部呈倒圆台形,整体高1 515 mm,体积约为1 m3,分为入鱼口、分级栅、取鱼口等3部分。在实验室用鲫鱼对分级栅进行了试验,结果表明,分级栅间距为15 mm和20 mm时,小规格鱼残留率平均为7.78%和4.75%,大规格鱼逃逸率平均为2.38%和3.00%。海上试验结果显示,大规格鱼捕获率90%以上。研究表明,通过日常投饵养鱼驯化将养殖鱼引诱至网箱内,通过提升网箱、驱使箱内小规格鱼群从分级栅游离,剩下的大规格鱼提出水面后迅速放入活鱼舱,从而达到捕大留小的目的。     

Live Chilling and Carbon Dioxide Sedation at Slaughter of Farmed Atlantic Salmon: A Description of a Number of Commercial Case Studies

ABSTRACT

Eleven commercial processing lines for the slaughter of Atlantic salmon were evaluated to investigate the efficiency of the refrigerated seawater live chilling method with respect to stunning fish and reducing body temperature. The method is commonly used in the Norwegian salmon industry to both stun and chill fish before killing. Carbon dioxide gas was added to the live chilling tanks, or in some cases, to a subsequent carbon dioxide stunning tank. Criteria used for evaluation were water quality parameters (dissolved oxygen, carbon dioxide, pH, temperature, total ammonium, ammonia, alkalinity, color, total organic carbon, and ferric ion), fish behavior, white muscle pH, and body and core temperatures. At two processing plants, fillet quality (Roche color, texture, ultimate pH, and water content) was also determined. The results are discussed in terms of fish acclimation temperatures, water quality, welfare, handling stress, chilling efficiency, pre-live chilling factors, refrigerated seawater live chilling process parameters, and fillet quality. Even though the live chilling method can be used to minimize fish handling stress during slaughter and may serve as an efficient chilling method, it was found in most cases that under commercial conditions when large biomasses were slaughtered, both handling stress and chilling efficiency were less than optimal. However, no adverse effects on the fillet texture and color were observed as a result of fish processing.     

宽体金线蛭生物学与养殖技术

介绍了宽体金线蛭的生物学和养殖技术，它可入药，对环境适应性强，喜钙。水深水浅，水面大小，均能生长，繁衍。除单独养殖外，还可与鱼，蟹混养。养殖，捕捞，加工方法简单。养殖投资少，见效快，经济效益较高。     

Physiological Stress in Channel Catfish,Ictalurus punctatus,Harvested by Lift Net,Vacuum Pump,or Turbine Pump

Stress in freshwater fish results in an increase in serum cortisol and glucose and a decrease in serum electrolytes. These physiological indicators of stress were measured in fignerling and food-size channel catfish, "Ictalurus punctatus," before harvest, immediately after harvest, and for several days after the fish were harvested. Fingerlings were harvested in spring with either a turbine fish pump or a traditional boom-and-basket lift net. Food-size fish were harvested in winter, spring, and summer by a turbine fish pump, a vacuum fish pump, or a life net. Elctrolyte concentrations were very stable and did not show consistent effects of harvesting. Cortisol and glucose were the most sensitive to harvesting, and both increased during harvesting in all months tested. Recovery of the serum concentrations to pre-harvest levels was generally completed by the fifth day after harvest. Stress responses were similar among the different harvesting techniques, which suggests that the method of choice may be based on other factors, such as cost of available facilities.     

Efficacy of Concentrated Algal Paste During Greenwater Phase of Cobia Larviculture

ABSTRACT

The purpose of this study was to determine if concentrated algal paste could effectively replace live algae during the greenwater stage of cobia fingerling production without negative impact upon larval growth or survival. Mean cobia survival per tank from 2 dph through post weaning at 28 dph for the live algae treatment was 24.44 ± 2.43% (mean ± SD) as compared to 24.47 ± 2.48% for the algal paste treatment. Furthermore, the number of fish produced per liter for the live algae treatment was 2.44 ± 0.24 fish/L compared to 2.47 ± 0.25 fish /L recorded from the algal paste treatment. Mean fish weight for cobia weanlings from the live algae treatment was 0.417 ± 0.059 g compared to 0.411 ± 0.026 g for the algal paste treatment. These observations demonstrate that during the greenwater stage of cobia larviculture, live algae can be completely replaced with commercially available, concentrated algal paste without negative impact upon cobia growth, survival, or resultant weanling production per unit volume.     

Mortality processes of hatchery‐reared Pacific bluefin tuna Thunnus orientalis (Temminck et Schlegel) larvae in relation to their piscivory

In mass culture of Pacific bluefin tuna Thunnus orientalis, yolk‐sac larvae of other species are fed as a major prey item to tuna larvae from 7 to 8 mm in total length. Marked growth variations in tuna larvae are frequently observed after feeding of yolk‐sac larvae, and this variation in the growth of tuna larvae is subsequently a factor leading to the prevalence of cannibalistic attacks. To elucidate details of the mortality process of hatchery‐reared tuna larvae after the initiation of yolk‐sac larvae feeding, we compared the nutritional and growth histories of the surviving (live) tuna larvae to those of the dead fish, found dead on the bottom of the tank, as direct evidence of their mortality processes. Cause of mortality of tuna larvae 3 and 5 days after the initiation of feeding of yolk‐sac larvae was assessed from nitrogen stable isotope and otolith microstructure analyses. Stable isotope analysis revealed that the live fish rapidly utilized prey fish larvae, but the dead fish had depended more on rotifers relative to the live fish 3 and 5 days after the initiation of feeding of yolk‐sac larvae. The growth histories based on otolith increments were compared between the live and dead tuna larvae and indicated that the live fish showed significantly faster growth histories than dead fish. Our results suggest that fast‐growing larvae at the onset of piscivory could survive in the mass culture tank of Pacific bluefin tuna and were characterized by growth‐selective mortality.     

影响黄鲷采捕成活率de因素

黄鲷是底栖性鱼类，具较高的经济价值和观赏价值。因其栖息水域较深，故获得活体的可能性较低。本文就温度、作业海域的深度、起网速度对黄鲷采捕成活率的影响进行了研究。     

气泡幕对许氏平鲉的阻拦效果研究

气泡幕可作为海洋牧场鱼群控制的技术手段之一。本研究通过改变气泡幕在水槽中的相对位置和试验许氏平鲉(Sebastes schlegeli)的密度来观察许氏平鲉的行为反应,运用了观察法、对照试验法和控制变量法探究了气泡幕对不同密度下的许氏平鲉的阻拦效果。结果显示:1)试验鱼20尾时,气泡幕的位置分别设置在矩形水槽长的1/4、1/2和3/4处(鱼的密度为12.52、6.26、4.17尾/m2),阻拦率分别达到了98.2%、88.4%和92.9%,阻拦效果明显。2)气泡幕设置在水槽长度方向的1/2处,试验鱼分别为5尾、10尾、15尾和20尾时,气泡幕阻拦率分别达到了100%、85.7%、100%和88.4%(鱼群密度分别为1.56、3.12、4.69、6.26尾/m2),阻拦效果良好。3)由于阻拦率较高,试验鱼群密度和阻拦效率没有明显的关系。本研究结果可为我国投放许氏平鲉的海洋牧场鱼群控制技术以及取水口拦鱼技术提供参考。     

Estimation of flow in a rearing tank of marine fish larvae by simplified numerical computation—a case of two-dimensional flow

Marine fish larvae are fragile against physical stress. However, few studies have been conducted to evaluate the flow field in a rearing tank, which is assumed to provide a high degree of physical stress to marine fish larvae. The flow field in a rearing tank (volume of 1 m³) is generated by aerators, which are commonly used to provide oxygen.

This paper is a report on the estimation of stationary flow in the rearing tank of marine fish larvae. The larvae are seven band grouper larvae of Epinephelus septemfasciatus, which have a very low survival rate immediately after the hatching of eggs. The experiments of rearing of seven band grouper larvae were carried out using rearing tanks with four aeration rates (1000, 200, 50 ml/min, and no aeration). The effects of aeration on the survival and floating death of seven band grouper larvae were examined. The experiments confirmed that the mass mortality of seven band grouper larvae depends on the flow rate in the rearing tank. Aeration at 200 ml/min resulted in the highest survival and growth rates of grouper larvae.

Larvae-rearing experiments provided evidence that the flow rates of the rearing tanks are very important design aspects of rearing tanks. The estimation of flow in a rearing tank for an aerating rate of 200 ml/min was carried out by numerical calculation. The computation was simplified by a two-dimensional flow based on experimental results. The calculated flow in the rearing tank was compared with the experimental one. The calculation of the stationary flow in the rearing tank showed good qualitative and quantitative agreement with the experimental results. The numerical estimation of the flow in a rearing tank of marine fish larvae was confirmed to be effective and satisfactory for the design of a tank that would provide optimum performance.