Chemical and Physical Properties of Shrimp Pond Bottom Soils in Ecuador

Chemical and physical analyses were conducted on bottom soil samples from 74 brackish-water ponds representing 40 shrimp farms in Ecuador. Most ponds had soils with pH > 6 and total carbon concentrations < 2.5%. Carbon was mostly in organic form, for the average concentration of carbonate carbon was 0.06%. The C: N ratio was 8 to 10 in soils with < 2.5% carbon. In ponds built in former mangrove areas, soil carbon was > 2.5% and C: N ratios were 25 to 30. Ponds soils in former mangrove areas also tended to be high in total sulfur and low in pH. Lack of correlation between carbon and sulfur in mangrove soils suggested that most of the sulfur was inorganic and presumably in sulfides. Soils containing above 0.4% free carbonate (as equivalent CaCO₃) had pH values > 7. Although carbonate concentration was a major factor controlling soil pH, calcium hardness of pond waters was strongly influenced by salinity (and calcium) in the water supply. Total phosphorus concentrations averaged 898 mg/kg, and dilute acid extractable phosphorus usually accounted for 25–35% of the total. Concentrations of major cations and minor elements varied greatly in soils and exhibited ranges of up to three orders of magnitude. Contrary to opinions of shrimp producers, many pond soils in Ecuador are not acidic and few soils have a high organic matter content. Proper use of soil and water testing could greatly improve the efficiency of liming and other soil management practices.     

Changes in the Concentration of Nutrients and Other Chemical Properties of Shrimp Pond Soils as a Function of Pond Use

Several soil nutrients, pH, organic carbon, and total soluble salts from the upper 10 cm of soil samples from 72 shrimp ponds in Texas were analyzed. Large increases in sediment concentrations of C, N, Mg, K, Na, Fe, Mn, Zn, Cu, B, nitrate, and water-soluble salts was observed after one production cycle, followed by an asymptotic increase in older ponds. An approximately linear increase in soil concentration of S and P with pond age was observed. The pH showed a marked decrease in ponds that had been used for one production cycle, but stabilized in older ponds. No correlation between Ca and growing cycle was observed. Calculated recovery rates for elements supplied in feed were less than 10% in several cases and 15% for P. No measurable negative effect on shrimp production by the increase of elemental concentrations was measured.     

Regression Analysis of Soil Chemical Composition for Two Shrimp Farms in Texas

Several nutrients, pH, organic matter, and total soluble salts of surface soil from 81 ponds on two Texas shrimp farms were measured. The relationship between shrimp yield and soil characteristics was analyzed statistically. Shrimp yield was negatively correlated with soil concentrations of S, P, NO₃^-, B, Ca, Mg, K, Na, Cu, and total water-soluble salts. Shrimp yield was directly correlated with soil concentrations of Fe, Mn, and organic matter. Stepwise multiple regression analysis indicated that Ca and S concentrations explained 54% of the variation in shrimp yield.     

Using Experimental Microcosms in Shrimp Research: The Growth-Enhancing Effect of Shrimp Pond Water

After preliminary six week experiments showed that shrimp pond effluent from an intensive culture growout pond had the capacity to nearly double shrimp growth in laboratory tanks, an 18 day experiment was designed to determine if similar results occurred in the presence of high quality feeds. The results presented here corroborate the hypothesis that autochthonous factors in shrimp pond water stimulate shrimp growth. These results revealed that performance of currently available shrimp feeds is greatly improved in the presence of pond effluent, regardless of feed quality. Increased feed performance did not appear to be an artifact of supplemental feed availability in pond effluent. The implications from these experiments are that, even in intensive culture systems (above 40 shrimp per m²), in-situ sources of nutrition play an important role in shrimp growth.     

普通虾池对虾无公害(Non-Pollution)健康养殖试验

为寻求无公害健康养殖的途径,我们进行了普通虾池无公害对虾健康养殖试验。经过114d的养殖,试验池塘收获成虾总产量27,505kg,平均单产8,595．31kg／hm^2;对比池塘收获成虾总产量12,157kg,平均单产7,598．13kg／hm^2;试验池塘总产值66．01万元,获利27．04万元,平均每亩池塘获利5,633元;试验池塘总产值26．75万元,获利7．1万元,平均每hm^2池塘获利44,370元。试验池塘与对比池塘相比,平均单位面积获利增长90．43％。试验池塘由于采用了无公害养殖技术,成品虾各项规定指标均符合食品卫生安全标准,达到无公害食品要求。     

杂色蛤与对虾混养技术

赣榆县1999年对虾(Penaeus chinensis)与杂色蛤(Ruditapes variegata)混养面积380 hm2,收获杂色蛤4 800 t,对虾125 t,取得了较好的经济效益和社会效益.本项生态农业技术模式适宜在硬泥或沙泥底质的虾塘泥滩推广,其技术要点如下:     

青虾池塘养殖试验报告

利用边坡较缓、淤泥较浅的２个池塘（共计３．３亩），通过人工设置水花生和网片附着物、投喂全价配合饲料、保持中度肥水等水质调节和病害防治措施，进行青虾养殖试验，结果亩产量 １１５．５ ｋｇ，亩利税 １７０９元，投入产出比 １：２．８８。指出池水透明度应保持 ３０～４０ｃｍ。     

分段养殖模式在凡纳滨对虾(Litopenaeus vannamei)养殖过程中的应用

通过测定凡纳滨对虾(Litopenaeus vannamei)生长性能和监测池塘水质变化,研究分段养殖模式在对虾养殖过程中的应用价值.养殖实验在6口池塘内(0.267 hm2/口)进行,首先在其中2口池塘内进行对虾的中间培育,养殖密度为300×104尾/hm2.经过36 d和48 d的中间培育后,将对虾先后转移到其他4口池塘内,养殖密度为60×104尾/hm2,分别记为T1和T2组.剩余的对虾继续养殖在中间培育池塘内,记为C组.结果显示,经过分段养殖的T1和T2组对虾,在分池养殖阶段7d内,生长速度均明显增加,其特定生长率(SGR)分别达到9.36 ％/d和6.76 ％/d;养殖期间,T1组具有最大的SGR (9.36 ％/d)和饲料投喂量,然而其饲料系数(FCR) (1.053)高于T2组(0.822);经过分段养殖的对虾FCR均低于C组(1.082).在分池养殖阶段的大部分时间,T2组对虾的SGR高于T1组;C组NH4+-N、NO2-N和Chl-a浓度低于T1组和T2组,而颗粒物含量(TPM)和总磷(TP)高于T1组和T2组;T2组Chl-a含量明显高于T1组和C组.结果显示,经过48 d中间培育后,即对虾体重约为2 g时进行分池养殖仍可保证对虾在较长时间内保持较大的生长速度,对于饲料的节约具有重要意义.由于分池养殖阶段具有较多的饲料投喂,经过36 d中间培育后的对虾具有最大产量.分池养殖池塘内饲料投喂少于全期养殖,有利于养殖系统的稳定,然而单位时间内投喂量增加则会影响水质.分段养殖模式在提高分池养殖阶段对虾的生长速度和保持水质稳定方面具有重要的应用价值.     

精养虾池的水色培养及调控方法

“养虾先养水”是业内人士都认同的观点 ,它说明了水色在对虾养殖生产中的重要性。在整个养殖过程中 ,要营造良好而稳定的水色是养虾技术的重点和难点。说起来容易 ,做起来难度很大。现针对对虾高产养殖生产中经常碰到一些有关水色调控的问题 ,提出一些处理方法 ,以供参考或共同探讨 :1　虾池水色的标准及作用水色是虾池水体理化因子的综合反映 ,它与水中浮游生物的种类和数量有密切关系。对虾养殖生产中通常以池水的颜色、透明度的大小和清爽度来衡量池水水色的好坏 ,良好的水色应是黄褐色、黄绿色 ,清爽而亮泽 ,硅藻和绿藻同时成为优势种…     

淡水青虾土池人工育苗技术

在土池中架设敞口式网箱，箱内放养抱卵青虾进行强化培育及幼虾孵化，通过适时培养生物开口饵料，及时投喂人工饲料，保持中度肥水等技术措施和20余天的培育，经验收小组确认，每亩生产1cm以上的虾苗 140余万尾。并对适宜青虾育苗的池塘生态条件及饵料生物培养，水质调节提出了自己的看法。     

南美白对虾室内池饲养与室外围塘饲养的比较

南美白对虾是一种优良的海水养殖对象，本文比较了室内水池饲养与室外土池饲养的结果，试验结果表明：室外围塘土池饲养经济效益较高，适宜推广，室内池饲养成本较高，可因地制宜开展。     

几种对虾池塘放养模式的生态效益评价

从生态效益角度对我国对虾池塘的几种放养模式进行了评价,综合放养模式符合生态平衡、物种共生互利以及对物质多层次利用等生态学原理,较之于单品种放养模式具有较高的生态效益,在我国具有强大的生命力和广阔的发展前景。     

日本沼虾水泥池育苗试验

选取450只平均抱卵量为960粒/尾健康活力强的抱卵虾作为亲本进行育苗试验,并对日本沼虾蚤状幼体分期进行系统观察。结果在孵化期间共获得蚤状幼体408 240尾,孵化率为94.5%,育苗后期共获得仔虾242 086尾,蚤状幼体发育到仔虾的成活率为59.3%,蚤状幼体可分为Ⅴ期。本试验结果为今后日本沼虾人工育苗技术推广提供参考。     

Shrimp Yields and Economic Potential of Intensive Round Pond Systems

Three intensive growout trials using Penaeus vunnumei were conducted in round ponds in Hawaii in 1987. A 337 m² experimental pond was stocked at 100 shrimp/m² for two trials; a 2,000 m² commercial prototype pond was stocked at 75/m² for one trial. In the experimental pond trials, shrimp survival averaged 88 ± 10% (SE) and feed conversion averaged 2.2 ± 0.2. Growth averaged 1.5 ± 0.3 g/week, yielding 18.2 ± 1.7 gram shrimp in 80 ± 5.5 days. Combined production in the experimental trials was 32,272 kg/ha in 174 days (from stocking of trial 1 to harvest of trial 2). Comparing these results to 1986 results (Wyban and Sweeney 1988), it was concluded that shrimp growth is not affected and production is doubled by increasing stocking density from 45/m² to 100/m². Pooling data from 1986 and 1987, a significant linear regression was obtained when weekly growth of shrimp above four grams individual size was regressed on mean weekly pond temperature: growth = 0.37 * temperature - 8.44, (r²= 0.41; P < 0.01). Multiple regression to examine effects of shrimp size, pond biomass, and shrimp age on the temperature-growth relationship was not significant. In the commercial prototype pond trial, survival was 67% and feed conversion was 2.0. Growth averaged 1.4 g/week, yielding 18.1 gram shrimp in 88 days. Production was 9,120 kg/ha. Individual shrimp size distribution at harvest in the commercial pond was similar to experimental pond results, indicating that shrimp growth in the two systems was comparable. Financial characteristics of a hypothetical 24 pond shrimp farm using these results were determined using an electronic spreadsheet model (hung and Rowland 1987). Feed costs were 40% of total operating costs while postlarvae and labor were 14% and 16% of total operating costs, respectively. Breakeven price (BEP) was far more sensitive to changes in revenuedetermining inputs such as survival and growth than to comparable changes in costdetermining inputs such as feed and postlarvae costs. Together these results suggest that commercial scale round pond production mimics experimental scale production and that round pond technology has commercial potential.     

微生态制剂对虾池水质影响的研究

以虾为研究对象来探讨微生态制剂对虾池水质的改良效果。在养虾池中分别加入光合细菌、芽孢杆菌以及不同浓度的微生态制剂,待其生长繁殖后测定氨氮、亚硝酸盐、溶解氧、COD值和pH值等各项水质指标。结果表明,微生态制剂对虾池水质具有较好的改善作用,其最适使用浓度约为2 0×1010个/m3。     

Ionic Supplementation of Pond Waters for Inland Culture of Marine Shrimp

Saline well water used to fill ponds for inland culture of marine shrimp in Alabama often have low concentrations of potassium and magnesium. In 2002, pond waters on a shrimp farm were treated with enough muriate of potash and potassium-magnesium sulfate (K-Mag) to increase potassium concentration from 6.2 mg/L to about 40 mg/L and magnesium concentrations from 4.6 mg/L to about 20 mg/L. Salinity in ponds averaged 2.6 ppt at the time of mineral salt additions. The concentrations of potassium and magnesium remained fairly constant throughout the growing season without further applications of salts, and salinity increased to about 4 ppt mainly as a result of concentration through evaporation. Survival and production on the farm averaged 19% and 595 kg/ha, respectively, in 2001. In 2002, average survival improved to 67% and average production was 4,068 kg/ha. Ponds were stocked at similar rates and managed by similar procedures both years. Magnesium concentration was very low related to the concentration expected in normal seawater diluted to the same salinity as the pond water, while potassium was near the expected concentration. Thus, increased potassium concentration is thought to have influenced production much more than did the increase in magnesium concentration. K-Mag does not dissolve as readily as muriate of potash. Thus, K-Mag should not be dumped in shallow water areas of ponds to dissolve as can be done with muriate of potash. It should be broadcast over the pond surface, predissolved and splashed over the pond surface, or placed in porous bags suspended in front of aerators. Although a single application of mineral salts was effective, 2002 was a dry year. On a wet year, ions may be diluted or flushed out in overflow and more than one treatment with mineral salts might be necessary during the growing season.     

Pond Bottom Management at Commercial Shrimp Farms in Chantaburi Province,Thailand

Most shrimp farmers in Chantaburi Province, Thailand, use water jets to dislodge sediment from empty pond bottoms, and wastewater is held for sedimentation before discharge into natural waters. Other pond bottom management practices used by a few farmers are sediment excavation, leave sediment but till entire pond bottom, and no mechanical treatment. All four methods of pond bottom treatment are followed by sun drying for 30 d. Soil organic carbon concentration in ponds following dry‐out seldom exceeded 2%. Although shrimp production in 24 ponds supplied by the same source of water was negatively correlated with increasing soil organic carbon concentration (r = ?0.582), this observation does not confirm a causative relationship. Moreover, in trials conducted at Burapha University, Chantaburi Campus, bottom soil organic matter concentration following dry‐out differed little irrespective of treatment method. Lower soil moisture concentration revealed that dry‐out was more complete with sediment removal than without, but better dry‐out resulted in lower soil pH. Removal of sediment by excavation or flushing is expensive, and natural dry‐out combined with liming and occasional sediment removal should be investigated as a less expensive and more environment‐friendly alternative to removing sediment after each crop.     

Disinfection, Microbial Community Establishment and Shrimp Production in a Prototype Biosecure Pond

Plankton community establishment and shrimp production in a prototype biosecure pond were compared to three control ponds. The biosecure pond was enclosed and intake water was disinfected, while control ponds were neither enclosed nor disinfected. All ponds were managed with no water exchange and stocked with 100 postlarvae/m², Litopenaeus vannamei . Residual oxidant concentrations in the biosecure pond dropped rapidly after cessation of chlorinated water addition. This was followed by a sharp increase in water column bacterial abundance, after which the pond was fertilized and inoculated with cultured Chaetocerous gracilis . After crash of the initial C. gracilis bloom in the biosecure pond, this species was not observed again. Following initial large fluctuations in biosecure pond bacterial abundance, phytoplankton biomass, oxygen consumption and nitrification rates, these parameters appeared to stabilize at levels similar to the control ponds. Early season compositional differences in phytoplankton, zooplankton, and bacterial communities were observed. No differences were seen in late-season phytoplankton and bacteria; however, zooplankton biomass tended to be lower in the biosecure pond than in the control ponds throughout the season. Shrimp production in all ponds was greater than 9,000 kg/ha. Production in the single biosecure pond was not a significant outlier compared to production in the triplicate control ponds.     

河口区中国对虾虾塘浮游生物调查研究报告

<正> 对虾养殖成败的关键问题之一是水质的好坏。水质恶化对对虾的生长不利,容易患病,甚至有可能导致全部死亡。观察虾池水色,是鉴定水质好坏的一种简单易行的方法。水色主要由浮游生物的种类和数量以及水中泥沙含量所决定,因此,研究虾池中浮游生物的种类和数量变化,探讨虾池水质的生物学指标,有助于提高对虾养殖技术。而     

The Impact of Aquaculture Pond Engineering Design on the Returns to Shrimp Farms

The effects of pond design on the internal rate of return of a 40 ha shrimp farm is evaluated. The influence of four pond construction parameters (pond size, pond shape, levee crown size and canal bank slope) on the total amount of earth moved and construction costs is determined using an engineering design model. The bioeconomic model, MARSIM, calculates returns to farms with the design modifications. Of the four parameters, the pond shape is the most influential over the range considered (from 17% to 8%). Pond size is the second most important parameter (from 17% to 21%). Levee width and canal bank slope influence are of lesser importance (<1% change).