Chemistry of Sediment Pore Water in Aquaculture Ponds Built on Clayey Ultisols at Auburn, Alabama

The composition of sediment pore water was determined for ponds constructed on clayey Ultisols at Auburn, Alabama. Pore water was anaerobic and contained much higher concentrations of ferrous iron (Fe²⁺), soluble reactive phosphorus (SRP), total phosphorus (TP), total ammonia-nitrogen (TAN), and sulfide (S²⁻) than surface or bottom waters. Concentrations of SRP and TP in pore water were higher in ponds with high soil phosphorus concentrations than in a new pond with less soil phosphorus. Increased concentrations of organic matter in soil or larger inputs of feed to ponds favored greater microbial activity in soils and higher concentrations of TAN in pore water. The pH of pore water was 6.5–7.0, and pH was apparently controlled by the equilibrium:

Movement of Fe²⁺, SRP, and S²⁻ from pore water into pond water apparently was prevented by the oxidized layer of soil just below the soil-water interface. Pond managers should concentrate on maintaining this oxidized layer to reduce the tendency for toxic substances to diffuse into the pond water.     

Effects of Aeration, Alum Treatment, Liming, and Organic Matter Application on Phosphorus Exchange between Soil and Water in Aquaculture Ponds at Auburn, Alabama

Application of readily-oxidizable organic substrate to laboratory soil-water systems and fish ponds caused anaerobic conditions in bottom soil and water, and concentrations of soluble reactive phosphorus (SRP) increased. Aeration of ponds increased total phosphorus (TP) concentrations by suspending soil particles in the water, but SRP concentrations declined because of increased oxy- genation of bottom water and soil, Alum [Al₂(SO₄)₃·14H₂O] treatment of ponds reduced SRP and TP concentrations in ponds, but the low concentration of alum used, 20 mg/L, had little residual effect on phosphorus concentration. Application of agricultural limestone at 0.2 kg/m² to ponds with soil pH of 5.5 and Ca²⁺ concentration of 5 mg/L did not affect SRP and TP concentration. Unless pond soils were anaerobic at their surfaces, a condition not acceptable in thermally-unstratified fish ponds, soils released little phosphorus to the water. Strong adsorption of phosphorus by soils in intensive ponds with feeding is beneficial, because removal of phosphorus by aerobic soils is a control on excessive phytoplankton growth. In fertilized ponds, phosphorus must be applied at frequent intervals to replace phosphorus removed from the water by soils.     

Geosmin Production by Cyanobacteria (Blue-green Algae) in Fish Ponds at Auburn, Alabama

Studies on production of geosmin, the compound responsible for earthy-muddy flavor in water and fish, were carried out at the Auburn University Fisheries Research Station. Water was collected from ponds during 44 cyanobacterial bloom periods from April to September. Geosmin ( trans -1, 10-dimethyl- trans -9-decalol) was detected at levels averaging 4.77 μg/L when Anabaena species with straight trichomes were predominant. Lower geosmin concentrations were associated with blooms of Anabaena species with coiled trichomes, Microcystis aeruginosa , and Aphanizomenon flos-aquae , and averaged 0.24, 0.12, and 0.07 μg/L, respectively. Study of four Anabaena blooms over a period of 4–8 weeks showed that changes in geosmin were correlated significantly with changes in trichome abundance. Geosmin disappeared from the water in seven days when Anabaena died. Comparison of geosmin concentrations in raw and filtered water showed that, on average, 90% of the geosmin could be associated with the particulate fraction. Dissolved geosmin concentrations ranged from 0.07–0.85 μg/L.     

Physical and Chemical Characteristics of Bottom Soil Profiles in Ponds at Auburn, Alabama, USA and a Proposed System for Describing Pond Soil Horizons

Soil cores were taken from each of three, 2-, 23-, and 52-yr-old research ponds (650–1,010 m² area) at Auburn, Alabama. Many physical and chemical variables changed in intensity with increasing depth in cores. Compared to original compacted pond soil, sediment contained more moisture; had lower bulk density (<1.4 g/cm³); possessed higher percentages of silt and clay; had greater porosity, specific surface area, and cation exchange capacity; and contained greater concentrations of organic matter and nutrients. Sediment organic matter was highly decomposed as evidenced by low proportions (5–15%) of carbon and nitrogen associated with the light fraction (soil retained on a 53-μm sieve). Sediment depth at 100-cm water depth increased with pond age (11.7 cm, 28.3 cm, and 48.3 cm in 2-, 23-, and 52-yr-old ponds, respectively), but sediment composition did not change greatly over time. Successive layers in cores were as follows: 1) water near the soil-water interface with a high concentration of solids; 2) high moisture content sediment with dry bulk density <0.3 g/cm³; 3) lower moisture content sediment with bulk density between 0.3 and 0.5–0.7 g/cm³; 4) rapid transition of bulk density from 0.5–0.7 g/cm³ to 1.4 g/cm³; 5) original compacted soil with bulk density of 1.4–1.7 g/cm³. We propose that these five layers be referred to as F (flocculent layer), S (stirred or mixed sediment), M (mature, bulk, un-mixed sediment), T (transitional layer), and P (original, undisturbed pond bottom) horizons, respectively. Superficial, oxidized sediment is termed an S_o horizon, and the reduced part of the S horizon is termed an S_r horizon. The upper part of the T horizon is an MT horizon when it is similar to the M horizon, or a FT horizon when it resembles the P horizon. A system for delineating horizons in pond soil profiles will be valuable in future attempts to classify pond soils.     

Water Temperature in Inland,Low-Salinity Shrimp Ponds in Alabama

Water temperature in eight ponds and air temperatures were monitored at 2-h intervals during the 2010 growing season at an inland, low-salinity shrimp farm in Alabama. There was a high correlation (P < 0.01) between mean daily air and water temperatures; pond water usually averaged 3° to 4°C warmer than air. Monthly mean water temperatures among eight ponds differed by 3.40°C in May and by 2.83°C in September, but there was less than 1°C difference among ponds in June, July, and August. Differences in temperature among ponds were not related to pond water surface:volume ratio, but in July and September there was a negative correlation (P < 0.05) with increasing aeration rate. Negative correlations (P < 0.05) between average water temperature over the entire culture period and survival and production of Pacific white shrimp, Litopeneaus vannamei, possibly resulted from variation in crop duration and were not causal. Nevertheless, differences in water temperature among ponds in May and September were great enough to have possibly caused differential shrimp survival and production among ponds.     

上覆水类型及流速对养殖池塘底泥耗氧速率的影响

为了探究上覆水类型及流速对养殖池塘底泥耗氧速率(SOD)的影响,在实验室进行6组水池平行实验,实验期为2 d,采用6个装置相同的玻璃缸进行对照实验,分别选取自来水和池塘原水作为上覆水体,在实验过程中利用水泵对上覆水进行循环流动,调节水泵循环流量以得到不同的上覆水流速,并采用2台溶氧仪测定不同实验条件下的上覆水水温和DO浓度,记录每次测量的对应时间点,测量间隔约为30 min。结果表明,当上覆水体为自来水和池塘原水时,在不同的循环流速下,SOD的范围为0.042~0.426 g/(m~2·d)。实验第2天各水池的SOD值较第1天均有一定下降,说明SOD随着水体中DO降低也相应减小,表明SOD与DO浓度有显著相关性。当上覆水处于静止状态时,其类型对SOD值有较大的影响,池塘原水在第1天和第2天的SOD值分别为0.426 g/(m~2·d)和0.297 g/(m~2·d),而自来水在第1天和第2天的SOD值均为0.258 g/(m~2·d),与上覆水体为自来水相比,有机物质含量高的池塘原水在第1天和第2天的SOD值分别高出65.12%和15.12%;当上覆水处于流动状态时,池塘原水的SOD为0.042~0.237 g/(m~2·d),自来水的SOD为0.045~0.252 g/(m~2·d),增幅仅为5.9%~15.0%,表明在此条件下上覆水体类型对实验水池的SOD值影响不显著。SOD与上覆水流速存在一定的相关性,对应最小的SOD值有一个流速较低值。     

不同修复方式下养殖池塘底质营养物质的迁移特征

自2013年12月8日起至2014年5月5日,以养殖池塘污染沉积物为研究对象,采用室内模拟法研究了种青、暴晒、投放生石灰等方法修复淡水养殖池塘沉积物的效果。结果表明,在池塘沉积物修复期,种青组沉积物中总氮和总磷的含量、碱性磷酸酶的活性、烧失量均显著低于对照组(P0.01);生石灰组沉积物中烧失量显著低于对照组(P0.01)。覆水处理后,种青组水体中正磷酸盐、叶绿素a含量显著高于对照组(P0.01),种青组水体总磷含量低于对照组(P0.05);暴晒组水体中正磷酸盐、总磷含量低于对照组(P0.05);生石灰组水体中各项指标均无明显差异。分析结果表明,种青、暴晒、投放生石灰降低了养殖池塘底泥中营养物质的含量,其中种青组沉积物中总磷的含量降低显著,覆水后水体中总磷的含量也有明显降低,以种青组的综合修复效果最佳。     

Effects of Major Water Quality Variables on Shrimp Production in Inland,Low‐Salinity Ponds in Alabama

Common water quality variables in nine, inland low‐salinity shrimp ponds in Alabama exhibited wide variation in concentrations among ponds and over time. Shrimp performance also varied considerably among ponds in 2008 as follows: survival, 16–128%; production, 928–5950 kg/ha; feed conversion ratio (FCR), 1.18–2.89. Measured water quality variables were not at concentrations high enough to be lethal to shrimp; but water temperature, dissolved oxygen, carbon dioxide, total ammonia nitrogen, calcium, and magnesium were occasionally outside optimum ranges for shrimp production and may have stressed shrimp. Survival and production both were positively correlated (P < 0.05) with increasing concentrations of methyl orange alkalinity, total alkalinity, and calcium hardness. Negative correlations (P < 0.05) between production and higher pH and water temperature may have resulted from lower water temperature and pH during final days of the crop in ponds harvested in October rather than from an actual effect of temperature and pH on growth. Nevertheless, those variables that were outside optimal ranges or correlated with shrimp survival or growth should be further investigated to ascertain whether or not excursions outside optimum ranges are harmful and to determine if observed correlations are causal.     

阿维菌素对池塘水质和浮游生物群落结构的短期影响

在湖北省公安县崇湖渔场3口面积均为0.268hm2的主养草鱼池塘中,施用剂量0.0375mL/m3的阿维菌素后,于第2、3、4、5、6d采样,测定池塘水质及浮游生物群落结构的短期变化。研究结果表明,阿维菌素可使池塘水体硝态氮水平显著下降,亚硝态氮、铵态氮和总氮水平显著上升;而对总磷、可溶性磷酸盐和pH值的影响不显著。施用阿维菌素前共镜检出浮游植物6门80种,浮游动物32属41种;用药后共检出浮游植物7门94种,浮游动物38属48种。其中,原生动物消失10种、新增9种,轮虫消失5种、新增10种,桡足类新出现3种成体。绿藻消失9种、新增10种,硅藻消失1种、新增8种,裸藻消失2种、新增7种,甲藻和金藻各新增1种。施用阿维菌素后,浮游动植物优势种显著变化,小型浮游植物种类增多。阿维菌素导致原生动物和枝角类的密度和生物量显著下降,桡足类数量显著上升,而对轮虫密度和生物量影响不大;同时裸藻、蓝藻、甲藻等部分浮游植物密度和生物量剧烈波动;使用阿维菌素的池塘易发生裸藻水华,应慎用阿维菌素。     

Distribution of Ground Water Suitable for Use in Saline-Water Aquaculture in Central and West-Central Alabama

Production of shrimp in inland ponds supplied by water from saline aquifers is a potential new aquaculture industry in Alabama. Examination of 2,527 well records of the Geological Survey of Alabama and the United States Geological Survey and samples from 35 wells revealed 238 wells with chloride concentration of 125 mg/L chloride or more in 11 counties of central and west-central Alabama. Chloride concentrations varied from 136 mg/L to 94,000 mg/L. The highest chloride concentrations were from wells in Washington, Choctaw, and Clarke Counties. However, 83% of the saline-water wells in Dallas, Hale, Greene, Marengo, Wilcox, and Sumter Counties were supplied by aquifers of the Eutaw, Gordo, McShan, and undifferentiated Eutaw-McShan formations. Water from these wells had an average and standard deviation of 1,238 ± 615 mg/L chloride. Based on the frequency of saline-water wells, the number of wells with chloride concentrations above 700 mg/L (about 2 ppt salinity), and well depths, it was concluded that Hale, Greene, Marengo, and Sumter Counties have the greatest potential for saline-water aquaculture. Contour maps for chloride concentrations and depths of wells in these four counties were prepared to better delineate this potential water source for aquaculture. There were, however, areas in Lowndes, Tuscaloosa, and Wilcox Counties with saline ground water suitable for inland aquaculture.     

地下泉水土池养殖欧鳗三类苗试验

1　材料和方法1 1　池塘条件养殖用池为永安市大湖镇罗溪养鳗场1号池塘,面积2986 7ｍ2,水源是地下泉水,水质条件符合淡水渔业标准。平均水深1 3ｍ,池塘形状为多边形,池塘底质为沙土,淤泥少。池中配备1台0 75ｋｗ水车式增氧机。1 2　池塘消毒在三类苗投放前1个月,排干池水,让池底曝晒1～2周后,用生石灰150ｇ/ｍ2溶解于水,全池泼洒,以杀灭淤泥中寄生虫和病原体,然后再用90%晶体敌百虫2 25～3ｇ/ｍ2泼洒,彻底消毒杀虫。在鳗苗投放前1周用1ｇ/ｍ3漂白粉全池泼洒消毒。1 3　苗种放养2001年5月4日从大湖镇罗溪养鳗场各口池中分选出三类苗3150ｋｇ(…     

4种金属离子对养殖水体中磷的去除作用的研究

对4种金属离子Al^3 、Ca^2 、Fe^3 、Fe^2 单因子和双因子联合作用对养殖水体中磷的去除效果进行研究。结果表明，单因子作用中以Al^3 和Ca^2 除磷效果较好，除磷率可达50％以上。双因子联合作用中，Al^3 -Fe^2 、Ca^2 -Fe^3 、Ca^2 -Fe^2 除磷效果较为显著，可达60％～76％。     

东平湖区池塘养殖罗氏沼虾试验

试验塘共4口，总面积0．71hm^2，共放养虾苗21．5万尾。经过一个养殖周期，共收获成虾1591kg，平均产量2241kg／hm^2，平均体重23．8g／尾。总收人79550，盈利37300元，投人产出比1：1．88。     

池塘养殖斑节对虾试验

养殖水面3.26hm^2，投放3cm虾苗7.05万尾/hm^2；养殖117d，产虾2794kg，平均单产1222kg/hm^2，养殖成本6.6万元/hm^2，饲料系数1.8。通过驯化使斑节对虾适应低盐度环境，以低盐底环境来抑制对虾病毒性疾病的发作。     

Evaluation of Limnocorrals for Studying the Effects of Phytotoxic Compounds on Plankton and Water Chemistry in Aquaculture Ponds

Abstract.— Two studies were conducted to evaluate the potential use of limnocorrals (in situ enclosures) for evaluating the effects of phytotoxic compounds on phytoplankton community structure and water quality. Limnocorrals consisted of open‐bottomed, fiberglass cylinders that were 2.44 m in diameter and 1.53 m high. The enclosures were placed in an aquaculture pond and allowed to settle 10–20 cm into the bottom mud, forming a watertight seal that isolated approximately 5.5 m³ of pond water. The first study evaluated the effect of water mixing on environmental conditions within limnocorrals. Mixing was accomplished by injecting air through airstones suspended inside the enclosures. Conditions in unmixed limnocorrals rapidly deviated from conditions in the pond and in aerated enclosures, with overall phytoplankton biomass decreasing while abundance of cyanobacteria and concentrations of soluble reactive phosphorus increased. Conditions in limnocorrals with continuous mixing also deviated from conditions in the pond. Environmental conditions among replicate mixed enclosures were, however, relatively consistent and stable for at least 2 wk. The second study evaluated the use of limnocorrals for testing the effects of phytotoxic compounds on phytoplankton community structure and water quality. A commercial chelated copper algicide was added to randomly selected, mixed limnocorrals at the label‐recommended rate. The algicide killed nearly all phytoplankton in the treated enclosures within 1 wk; however, treated limnocorrals were rapidly recolonized by green algae and diatoms. Conditions in untreated limnocorrals remained relatively stable and consistent among replicates for 16 d, after which total phytoplankton biomass began to decrease, possibly due to nutrient depletion within the enclosures. Although conditions inside the enclosures deviated with time from those in the surrounding pond water, mixed limnocorrals appear to provide a convenient and reliable method for short‐term studies of algicides and other water quality manipulations.     

水泥池微流水养殖杂交鲟试验

1　材料和方法1 1　试验材料1.1.1　试验鱼　试验用鲟鱼种为北京禧丰达渔业有限公司购进的杂交鲟鱼种。受试鱼 2 0 0 0尾 ,开始进行人工配合饲料驯化时其体长为 4 5～ 5 5ｃｍ ,体重 1ｇ左右。1 1 2　饲料　养殖试验用饲料 ,前期为山东升索渔业饲料研究中心生产的鱼苗专用微粒饲料 ,其基本营养成分为粗蛋白 5 4%、粗脂肪 10 %、粗纤维 2 0 %、灰分 15 %、钙1 5 %、磷 1 5 %。后期为丹麦进口的“爱乐”牌鲟鱼专用饲料 ,其基本营养成分为粗蛋白 45 %、粗脂肪 16 %、粗纤维 2 0 % ,饵料为沉性颗粒状 ,粒径 2 0～ 3 5ｍｍ。1 1 3　鱼池　利用…     

辽宁省池塘养殖废水排放的分布及其对水环境的影响

对我国第一次污染源普查辽宁省池塘养殖业污染源普查数据进行统计分析,2007年度辽宁省池塘养殖业养殖总面积为4.70×104 hm2,排水总量为1.08×1010 m3;主要污染物排放量分别为总氮1546.23t,总磷123.31t,化学需氧量11102.91t,铜-717.03kg,锌5266.87kg。分析了池塘养殖业养殖废水对水环境的影响,并针对减少池塘养殖业的污染物排放、改善水环境质量提出了相应的建议和措施。     

Nitrogen,Phosphorus, and Carbon Concentrations in Some Common Aquaculture Feeds

Nitrogen, phosphorus, and carbon concentrations were measured from 203 samples of starter, fingerling, and grower aquaculture feeds from several countries and for several common species. The feed protein concentrations reported by manufacturers often were slightly greater than the measured crude protein concentrations. The correlation coefficients (R²) between feed nitrogen and carbon concentrations were less than 0.50, and nitrogen and phosphorus concentrations in feed were not correlated. There were considerable differences in elemental concentrations among feeds, but the overall averages for carbon, nitrogen, and phosphorus concentrations, respectively, were as follows: starter feed 41.36, 7.78, and 1.57%; fingerling feed 39.75, 5.95, and 1.36%; grower feed 39.97, 5.36, and 1.22%. Concentrations of carbon, nitrogen, and phosphorus in feeds are required in estimating the pollution potential of aquaculture facilities. The crude protein concentration – if provided by the manufacturer – can be used to estimate nitrogen concentration in feed, but carbon and phosphorus concentrations should be measured.     

Viability of a Freshwater Mussel (Elliptio complanata) as a Biomechanical Filter for Aquaculture Ponds II: Effects on Aquaculture Pond Water Quality

Bivalves have been proven to be an inexpensive method for removing suspended solids, dissolved nutrients, and controlling algal growth through suspension feeding. The freshwater mussel, Elliptio complanata, is one of the most abundant species in Delaware, and it is additionally favorable for this experiment because of its hardiness against environmental stress and its filtration efficiency. This study examines the possibility that biomechanical filters such as E. complanata can supplement existing chemical and mechanical filtration regiments in aquaculture pond management. Twelve earthen aquaculture ponds located at the Delaware State University were stocked at a density of 4,000 catfish (Ictalurus punctatus) per hectare. Four different concentrations (0, 75, 150, and 300) of E. complanata were placed in trays within the ponds with three replicates of each concentration. The trays were suspended 15 cm below the surface of the water for a period of five months. Fish were fed a 32% protein diet twice daily at a rate of 1% of their body weight. Water quality was analyzed weekly while fish and mussel growths were measured biweekly. Results from water quality parameters varied significantly and were not conclusive based on the data obtained in this study. Water quality did not improve within the mussel treatment ponds during the course of this study and was found to be significantly below that of control ponds for all of the water chemistry parameters measured, with the exception of ammonia. Catfish in the 150 mussel treatment ponds grew the fastest; the 75 mussel treatment provided the most growth in mussels; and the 300 mussel group maintained the highest mussel survivorship. Although there were differences between ponds, fish growth and survivorship were not significantly different between treatments. While our mussel densities may have not been sufficient, their placement within the water column may have added additional stress. Being removed from the sediment can result in a decreased clearance rate in a benthic species such as E. complanata. This study may not have been conclusive in proving that mussels can be used to maintain water quality in aquaculture ponds, but we did see positive growth and survivorship of mussels and fish that indicated that the mussels were thriving in the aquaculture pond setting. This study may show that aquaculture ponds provide a suitable habitat in which propagated mussels may be held until their release into native areas.     

Evaluation of Soil pH-Percent Base Saturation Relationships for Use in Estimating the Lime Requirements of Earthen Aquaculture Ponds

The pH-percent base saturation relationships of selected subsurface soil horizons were evaluated by fitting theoretical and empirical models to published soils data. The selected models were validated by fitting them to an independent set of data. The selected models did not fit the second set of data as well as the original data, but they provide initial approximations for use in cases when real values can't be measured. Possible reasons for the poorer fit to the second data set are discussed. One possibility for increasing the range of soils to which suitable pH-percent base saturation models can be fit is to refine the soil classification system being used. Valid pH-percent base saturation models can be combined with on-site soil pH measurements and typical cation exchange capacity values to estimate aquaculture pond lime requirements on a broad range of soil types in the field i.e., without reliance on laboratory analyses.