Mineral fertilization of carp ponds in polycultural rearing

The fertilization of carp ponds as an important intensification means has been utilized in Europe since the first half of the 19th century, but even in most intensive fertilization the concentration of nitrogen (N) hardly exceeds 2 mg/l and of phosphorus (P), 0.5 mg/l.Polycultural carp growing using intensive mineral fertilization (weekly and every 3 days) has been experimented in the Freshwater Fishery Research Station in Plovdiv in the 1971–1972 period.The greatest zooplankton and benthos biomass and the greatest fish growth per ha water area are obtained with 3-day mineral fertilization with ammonium nitrate, 708 kg/ha and superphosphate, 395 kg per hectar. The average monthly water temperature in the experimental ponds during the vegetation period (June–September) fluctuates between 21.5 and 24.7°C. The oxygen dissolved (O₂) during the day hours changes within the average of 4.9–7.6 ml/l and the aeration is normal for the carp ponds (4.0–8.1 mg O₂/l). The highest average seasonal zooplankton biomass in mixed fertilization (mineral and organic) is 2.437 g/m³. The zooplankton is represented by the following variaties: Rotatoria — Brachionus calyciflorus; Copepoda — Acanthocyclops vernalis and Cladocera — Moina rectirostric. The benthos consists of: chironomid larvae (family Chironomidae, Diptera) and Oligochaetae. The highest average seasonal biomass of the benthos is established with three-day mineral fertilization, 1.472 g/m². The total fish growth with three-day fertilization is 300 kg/ha higher than in the control ponds (without fertilization). The best fishery results have been achieved with three-day fertilization giving a total growth of the fish of 2 730 kg/ha and a food coefficient of 2.8.     

施肥对多盐水池塘浮游植物演替的影响

选择辽宁盘锦光合水产有限公司养殖基地为试验场所,于2002年春季4~5月进行试验。选择5个具有代表性的土池作为试验池,同时另选一土池作为对照池。研究相同N/P比值下不同施肥量对室外土池多盐水体的水化学和浮游植物群落、叶绿素a含量和初级生产力的影响,以及浮游动物对浮游植物的下行效应。共检出浮游生物42种。其中,浮游植物33种,浮游动物9种。浮游植物生物量高达288.2 mg.L-1,优势种为蛋白核小球藻(Chlorella pyrenoidesa)。叶绿素a含量为5.89~325.44μg.L-1。各池在第2次施肥后5~6天,叶绿素a含量达到高值,之后开始下降,8~9 d后恢复到原来水平。初级生产力均值为4.40 g(O2).m-2.d-1,呈低-高-低的变化,极值为1.25 g(O2).m-2.d-1和10.92 g(O2).m-2.d-1。以施N 2.0 mg.L-1、P 0.3 mg.L-1的4#池高峰期维持最长,施肥量的不同对浮游植物的生物量、种类数和种类组成影响较大。在北方地区的多盐水池塘,施氮磷混合肥能有效促进小球藻等藻类增长,达到定向培育的目的。     

Control and utilization of inorganic nitrogen in intensive fish culture ponds

One of the main obstacles toward the intensification of aquaculture systems is the accumulation of inorganic nitrogen in the water, A solution demonstrated in this work is to control inorganic nitrogen levels through the induction of microbial protein synthesis. This is achieved by adding a carbonaceous substrate, adjusted in a way so as to supply the needed carbon to immobilize all the non-utilized nitrogen. Inorganic nitrogen levels are reduced due to the resulting production of microbial protein. The in situ produced microbial protein is a substitute to the protein added with the feed. Fish growth in the treated ponds was higher than the growth in conventionally fed ponds. Protein utilization was doubled due to the recycling of nitrogen in the pond system, leading to diminution of the deleterious inorganic nitrogen accumulation. The price of feed was reduced to 50-67% of that common in conventional ponds, due both to replacement of protein and limited wash-out of feed.     

Determination of the phosphorus fertilization rate for bluegill ponds using regression analysis

Pond fertilization studies usually are restricted by availability of ponds forcing researchers to limit treatments to maintain adequate replicates for statistical analysis. Data from a wide range of fertilizer rates applied over a single season in un‐replicated ponds were treated using regression analysis to establish the optimum phosphorus application rate for bluegill (Lepomis macrochirus) ponds. The response to phosphorus fertilization conformed to a saturation model (R²=0.92). Bluegill production increased with greater fertilization rate up to 3 kg P₂O₅ ha^?1, but production was similar (501–558 kg ha^?1) at rates of 3–7 kg P₂O₅ ha^?1. The observation that 3 kg P₂O₅ ha^?1 per application was adequate phosphorus fertilization for bluegill ponds with sufficient nitrogen agrees closely with the usual recommendation of 4 kg P₂O₅ ha^?1 per application. Results of this research also revealed that nutrient assessment in bluegill ponds can be based on total nitrogen and total phosphorus analyses, and Secchi disk visibility may be used as an index of plankton abundance.     

Growth of Tilapia nilotica in ponds with differing histories of organic fertilization

A series of six 0.04 ha ponds that had received varying rates of organic fertilization during 1976 and 1977 were each stocked with 200 Tilapia nilotica for a 3.5 month period during the 1978 growing season. Slotted feeding floors were placed over five of the six ponds and two growing-finishing hogs were placed on each feeding floor. The sixth pond received neither manure nor supplemental feed. Growth of T. nilotica was most rapid in ponds that had a history of relatively high manuring rates. Condition factors paralleled fish growth. Survival was 75% or more in each of the ponds with no apparent correlation between percent survival and history of manuring. Water quality was similar and acceptable for tilapia in each of the six ponds. The data indicated that a stocking rate of 50 hogs/ha can result in high fish yields; and that the history of a pond's experimental use influences subsequent experimental results.     

Responses of phosphate solubilizing bacteria to qualitatively different fertilization in simulated and natural fish ponds

The growth of phosphate solubilizing bacteria (PSB) was examined inresponse to pond fertilization with poultry dropping (PD) (12,500 kgha^–1 y^–1), cattle manure (CM) (25,000 kg ha^–1 y^–1), inorganic fertilizer (IF) consisting of urea (10.83 kg ha^–1 y^–1) and single super phosphate (43.52 kg ha^–1 y^–1) and inorganic-organic mixed fertilizers (PD:CM:IF – 1:1:1) in simulated fish ponds under alluvial and laterite soil conditions as well as in natural pondslocated in alluvial soil zone. The high correlation between dissolved oxygenand density of PSB implied the contribution of the latter in the aerobicorganic decomposition. The PSB were maximal in the PD, and minimal in theIF treatments. The distribution pattern of PSB was related to theautochthonous C/N ratio and the N/P ratios of water. Relatively low C/N ratios caused greater abundance of PSB. Increased fish production in PD treatments was clearly due to increased primary productivity and higher zooplankton abundance resulting from nutrient-grazing-detritus-microbial-food chain complex pathways.     

全雄太阳鲈网箱养殖技术的研究

2 0 0 1年设置 2m× 2m× 2 5m网箱 6只 ,其中 3只放养密度为 4 0 0尾 /m3 ,鱼种规格 2 2cm ;另 3只放养密度为 5 0 0尾 /m3 ,鱼种规格 2 7cm ,试验期 180d。 2 0 0 2年设置 2m× 3m× 3m网箱 6只 ,3只一组。一组放养密度为 375尾 /m3 ,鱼种规格 4 0cm ;另一组放养密度为 4 17尾 /m3 ,鱼种规格 6 5cm ,饲养期16 0d。 2 0 0 1年成鱼起捕平均规格为 0 17kg/尾 ,单位产量 6 2 6kg/m3 ,成活率 80 9% ,单位箱体纯收入996 6 7元 /m3 。 2 0 0 2年成鱼起捕平均规格为 0 2 4kg/尾 ,单位产量 87 1kg/m3 ,成活率 90 7% ,单位箱体纯收入 10 90 6元 /m3 。试验证明 :全雄太阳鲈适合高密度的网箱养殖。     

Fertilizing fish ponds: III. Growth of Mugil capito in Egypt by pond fertilization and feeding

The possibility of increasing the growth rate of M. capito fry by using supplemental artificial food and different fertilizers in seven ponds at Mex Experimental Station, Alexandria, is discussed. Growth was indicated by an increase in the length and weight of the fish.The experiment demonstrated different patterns of growth of M. capito. The best growth rates for the adolescent fish are achieved by using supplemental artificial food composed of powdered blood and flour. The next best results are obtained with the cheaper cotton seed cake and rice bran. The increase in the growth rate of the fish in the ponds fertilized with superphosphate and superphosphate plus nitrate, is lower for the 6–12-month-old fish, while it is highest from the fry stage until 6 months of age. Obviously there is a considerable difference between the treated and untreated ponds.     

Fertilizing fish ponds: II — Growth of Mugil cephalus in Egypt by pond fertilization and feeding

Growth of Mugil cephalus, indicated by increase in length and weight, was studied in seven ponds at Mex Experimental Station, Alexandria. The ponds were treated with different fertilizers and the fish were given supplemental artificial food.Different patterns of growth were studied and compared. The best and cheapest method of increasing the growth of M. cephalus in experimental ponds was to fertilize with superphosphate at a monthly rate of 20 kg. The increase in the growth rate of the fish in ponds receiving superphosphate, and superphosphate plus ammonium nitrate indicated by condition factor values was nearly double that reported by other investigators.     

Experimental evaluation of inorganic fertilization in larval giant grouper (Epinephelus lanceolatus Bloch) production

A major constraint in successful larviculture of groupers has been the small gape of the larvae and hence the requirement for small prey at first feeding. In this study, we examined how maintaining a phosphate concentration of 100 μg P L^?1 and an inorganic nitrogen (N) level of 700 μg N L^?1 via weekly fertilization with inorganic fertilizers affected phytoplankton, zooplankton and giant grouper larval survival in relation to a control group that was provided with rotifers immediately after larvae hatched. Unicellular algae, zooplankton within the size ranges of 10–50 μm and 50–100 μm and survival of giant grouper larvae were all significantly higher in the fertilized treatment compared with the control. Stomach analysis revealed that ciliates and flagellates were actively consumed by larval fish in the fertilized group, whereas few rotifers were consumed in the control. We conclude that the inorganic fertilization method provides high densities of suitable‐sized prey for larval groupers at the onset of exogenous feeding before they are able to consume larger, commercially available rotifers and copepods.     

Effect of varying closes of organic and inorganic fertilizers on plankton production and fish biomass in brackish water fish ponds

The effects of four different doses of organic (cowdung) and inorganic fertilizers (single super phosphate: SSP) in combination were studied on plankton production, species diversity and fish biomass in saline and freshwater fish ponds. Physico-chemical factors of pond waters were also monitored. Alkalinity and nutrients increased with increase in the dose of fertilizers. Dissolved oxygen (DO) also remained sufficiently high up to the third treatment; however, levels declined significantly in the ponds receiving the fourth treatment (20 000 kg ha^-1 year^-1 of cowdung and 3000 kg ha^-1 year^-1 of SSP). The highest plankton population, species diversity and higher fish biomass was also observed in ponds which received the third dose of fertilizers (10 000 kg ha^-1 year^-1 of cowdung and 1500 kg ha^-1 year^-1 of SSP). However, a decline in these parameters was observed in ponds which received the highest (fourth treatment) dose of fertilizers. Nutrients remained slightly lower in brackish-water fish ponds. When species diversity values were compared, it was observed that, although values werte higher in freshwater ponds, their abundance (no. 1¹) remained lower than in brackish-water fish ponds. Similarly, fish biomass also remained significantly higher in brackish-water ponds than in freshwater ponds. From these studies, it can be concluded that a combination of 10 000 kg of cowdung + 1500 kg ha^-1 year^-1 of SSP appears to be the optimum dose.     

Combined effects of fertilization rate, manuring and feed pellet application on fish performance and water quality in polyculture ponds

This study analyses the combined effects of organic and inorganic fertilization and of feeding with pellets on fish performance and water quality in a polyculture of common carp. Cyprinus Carpio L., silver carp. Hypophthalmichthys molitrix (Val.), grass carp. Ctenopharyngodon idella (Val.) and hybrid tilapia, Oreochromis niloticus L. x O. aureus Stetndachner. Experiments included six treatments, which are combinations of inorganic fertilisation (daily or fortnightly), manuring (supplied or not), feed pellets (supplied or not) and density of phytoplanktivorous fish species (high-density treatments with 50% more hybrid tilapia and 300% more silver carp than low-density treatments). The effects of the management procedures on fish weight, growth, survival and yield. plankton abundance, water quality, and their complex interactions at the different levels of the natural food web were analysed. The hypothesis that daily fertilization should increase algal production, which in turn should sustain a higher density of phytoplanktivorous fish, proved to be correct within certain limits. Algal reproduction rate was higher under daily fertilization, pointing to better supply of food for herbivorous fish, while algal biomass was similar under both fertilization regimes, pointing to the utilization of that algal food supply. The increased algal food supply sustained a 50% density increase of the omnivorous tilapia, but not the 300% density increase of the grazer silver carp.     

刺参养殖技术之二刺参虾池健康养殖技术

虾池养参是刚刚兴起的养殖模式。由于对虾养殖的利润下滑以及病害问题严重,在我国北方山东、辽宁地区的很多对虾池塘改养刺参。但刺参在虾池养殖过程中仍然存在不少问题,若要达到高产高效,需要规范的技术环节很多。现将虾池养殖刺参技术介绍如下:     

Growth and survival response of Penaeus stylirostris (Stimpson) to fertilization, pelleted feed and stocking density in earthen ponds

Abstract. Growth and survival response of Penaeus stylirostris (Stimpson) to fertilization, pelleted feeding and stocking density were analysed for the conditions prevailing on the Baja California peninsula (Mexico). Three 0·25-ha earthen ponds were longitudinally divided in half with mesh structures. One half received inorganic fertilization (trial F) and the other supplementary feeding using a pelletized ration (trial PF). The initial stocking rates were approximately 5, 10 and 15 PL5/m² in both trials. After 210 days, final mean weights ranged from 15·0 to 5·3g and survival from 48·6 to 17·8%. Growth and survival were analysed by means of a reparameterization of the von Bertalanffy's growth model and the exponential mortality equation. Results indicated that: (1) final mean weight was dependent on density in both trials ( P < 0·01) although growth rate was only affected in trial PF ( P < 0·01); (2) pelleted feeding produced both greater final mean weight and increased growth rate at densities higher than 5 PL/m² ( P < 0·005); (3) the ratio tail weight/total weight was influenced by density in trial F ( P < 0·015); (4) the mortality equation served to explain differences in survival to a limited extent. An increase in growth rate after 170 days occurring at the intermediate density in trial PF was attributed to an increase in mortality, which allowed the remaining individuals to attain larger sizes. Further research to increase biomass yields should focus on the optimization of pond depth, the supply of vigorous post-larvae and on the possible influences of seasonal variations of planktonic communities of the lagoons on the productivity of ponds.     

Effect of fertilization frequency on pond productivity and fish biomass in still water ponds stocked with Cirrhinus mrigala (Ham.)

Four different fertilization frequencies, namely twice per week, once per week, twice a month and once a month, were used in ponds to assess their effects on nutrient release, pond productivity and fish biomass. All ponds received the same total fertilizer inputs during the experimental period of 60 days (cow dung 208.3 kg ha^?1 week^?1, TSP 9.8 kg ha^?1 week^?1, urea 6.0 kg ha^?1 week^?1). Studies have revealed that the highest values of fish biomass, specific growth rate (SGR), net primary productivity (NPP), plankton population and nutrients were observed in the ponds that were fertilized twice a month. A strong and significant correlation of fertilization frequency was observed with dissolved oxygen, biochemical oxygen demand (BOD), alkalinity, nutrient release, NPP, plankton density (no. L^?1), fish biomass and SGR. The linear relationship between NPP and fish biomass/SGR for all the ponds was strong (r²= 0.88). Sediment chemistry revealed that O‐PO₄, NO₃‐N, organic carbon and electrical conductivity (EC) increased significantly (P<0.05) with a decrease in the frequency of fertilization, while alkalinity and calcium were high in ponds that were fertilized twice a month.     

池塘投饵机控制系统

根据北方池塘投铒的实际要求，结合电路控制的各项性能，研制开发了一种新型的投铒机控制系统。应用逻辑电路和定时器电路进行控制，使用拨码开关技术设置定时时间、自动重复启动的间隔时间和投铒的各项参数，并具有延时投铒功能。操作简单直观、定时准确、抗干扰能力强，解决了定时定量、准确投喂的问题，避免了铒料投喂的浪费。     

The brackish ponds at Killingholme,Humberside, UK

1. The National Power site at Killingholme, on the Humber Estuary, contains three brackish ponds at the northeast corner, adjacent to Killingholme Haven. The ecology and conservation importance of these ponds were surveyed as part of a Nature Conservancy Council lagoon research programme in 1986 and by National Power staff in 1990 and 1991. 2. The north and west ponds were found to be saline, and both supported the nationally rare polychaete worm Alkmaria romijni. The east pond was fragmenting, owing to the incursion of the reed Phragmites australis, and predominantly freshwater. 3. A total of nine characteristic lagoonal species was present in the system. 4. In 1990 the saline ponds had been allowed to dry out extensively, which was detrimental to the lagoonal species. 5. The surveys concluded that the system of ponds is of national importance for conservation on account of its invertebrate community, particularly with the diversity of lagoonal habitat it offers. Optimum management of the system for conservation is discussed.     

The effects and control of algal blooms in fish ponds

It has been demonstrated that large quantities of ammonia may be released into the water of a fish pond following the collapse of an algal bloom. Some blue-green algae are thought to release toxins. This paper puts forward another explanation for this occurrence. A review of the disease known as Infectious Dropsy of Carp (IDC) based on the findings of this paper shows it to be caused by ammonia. Various methods to counteract this disease are described. Particular emphasis is placed on the policy concerning the addition of fertilizers. It is shown that dense blooms of nitrogen-fixing algae can be controlled by manipulation of the nitrogen: phosphorus balance of ponds. Determination of the aetiology of carp dropsy will probably lead to a better understanding of other diseases of fish which are manifested by similar symptoms. The disease of trout known as Viral Haemorrhagic Septicaemia (VHS) is discussed in this context. For clarification it is proposed that infectious dropsy of carp be renamed Environmental Ammonotelic Syndrome (EAS).     

刺盖太阳鲈池塘养殖试验

刺盖太阳鲈俗称海鲈鱼,隶属于鲈形目、鳍鲈科,是一种溯河性鱼类,它具有生长快、养殖周期短、抗病力强、食性杂、适温范围广等特点。刺盖太阳鲈是一种名贵鱼类,其肉质鲜嫩、营养丰富、蛋白质高、销售价高等优点,深受广大消费者的喜爱。为探索其池塘养殖技术,笔者进行了刺盖太阳鲈池塘养殖研究,现介绍如下。1试验地点与池塘条件1.1鱼种放养前的准备工作在浙江省绍兴县富盛镇仪峰村许国明养殖场,4口池塘,面积1.4 hm2,池深1.5 m,池底淤泥厚8 cm,水源充足,水质清新,无污染,进排水方便,池塘水均可完全排干,并且装有防盗设备,增氧机及排水机等设施…     

垂钓鱼塘的饲养管理

随着人民生活水平的提高,每逢节假日,城郊有池塘的地方,持竿垂钓者络绎不绝。伴随着垂钓业的发展,交通、旅游、餐饮乃至娱乐行业都跟随而至。这为休闲渔业提供了千载难逢的发展机遇。目前,不少养鱼户纷纷改建专供垂钓的养鱼池,集垂钓、售鱼、餐饮为一体,养殖效益大增。供垂钓的