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1.
Influence of initial sediment phosphorus content of the pond sediment on P dose efficiency was examined in a laboratory experiment using four types of sediments collected from ponds located along a nutrient gradient in a sewage‐fed fish farm. Each sediment type (500 g) was dispensed in a glass jar with water and treated with single super phosphate (SSP) treatment at 1.25, 2.5, 5.0 and 10.0 mg L?1 in triplicate. Determination of orthophosphate (OP) and soluble reactive phosphorus (SRP) in water and available and total P in sediment showed increased response in relation to dose and time. At a given dose, the rate of increase for all species of phosphate in sediment or water was maximum in the case of local pond (LP) soil followed by stocking pond (SP), facultative pond (FP) and anaerobic pond (AP) soil, suggesting that utililization of phosphate fertilizer was much better under oligotrophic conditions than under eutrophic states. The SSP‐induced OP peak at 10 mg L?1 in LP sediment was similar to that of 5.0 mg L?1 in AP sediment containing 59% enhanced initial phosphate, implying that fertilizer application can be profitably reduced by 18% in the former without limiting the OP level in the water phase. It is concluded that dosage selection of phosphorus fertilizer in aquaculture ponds should be based on an evaluation of the initial P status of the system.  相似文献   

2.
3种水质调控方式下参池沉积物酶活性的比较研究   总被引：1，自引：0，他引：1  
2015年10月至2016年9月对自然纳潮、微孔曝气、养水机3种水质调控方式下海参池塘沉积物中淀粉酶、蛋白酶、碱性磷酸酶、脱氢酶的活性进行了跟踪比较研究。研究结果显示,3种水质调控方式下池塘沉积物中的淀粉酶活性年变化为0.126~0.880 mg/g,年均值(0.410±0.180) mg/g,蛋白酶活性年变化为0.024~0.472 mg/g,年均值(0.190±0.103) mg/g,碱性磷酸酶活性年变化为0.068~1.042 mg/g,年均值(0.340±0.196) mg/g,脱氢酶活性年变化为12.092~52.794 mL/g,年均值(26.980±8.295) mL/g。3种水质调控方式下池塘沉积物中蛋白酶、碱性磷酸酶及脱氢酶活性均在自然纳潮池塘中均值最高,变化幅度最大;淀粉酶活性均值则在自然纳潮池塘中最低,养水机池塘最高,这与养水机池塘有机质最低,自然纳潮池塘最高,养水机池塘沉积物的细菌多样性最高,真菌数量最多有关。表明养水机能够快速去除沉积物中氮、磷有机化合物,有利于池塘的正常物质循环。本研究从沉积物酶活性的角度,探讨了养水机的作用效果与其他两种水质调控方式产生差异的机理。  相似文献   

3.
The industrial aquaculture pond system has gradually replaced the use of traditional earthen pond, as it causes less pollution and is more economical. In this study, an industrial ecological purification recirculating aquaculture system consisting of the water source pond, high‐density culture ponds, a deposit pond, and ecological purification ponds for channel catfish cultivation was established. Twelve water samples from different ponds were sequenced, and the bacterial communities were analysed. The abundances of Cyanobacteria and Merismopedia varied in different functional ponds of the system. The water quality was stable after two months of cultivation at 1.89 ± 0.22 mg/L total nitrogen, 1.1 ± 0.08 mg/L NH4‐N and 0.43 ± 0.1 mg/L total phosphorus. The fish weight increased in a nearly linear manner, reaching 237.63 ± 23.8 per fish at day 120. An analysis of the environmental parameters, water quality and fish weight suggested that the system had an effective water purification process. Canonical correspondence analysis showed that the community was affected at the genus and phylum levels by different environmental parameters. We identified several dominant beneficial bacteria with nutrient removal abilities. Overall, our results demonstrated that the ecological purification recirculating aquaculture system had notable effects on water quality improvement and promoted changes in bacterial populations. These results provide important information on the microbial ecology of pond industrial eco‐aquaculture systems.  相似文献   

4.
In this study, we evaluate the use of polymerase chain reaction‐denaturing gradient gel electrophoresis (PCR‐DGGE) for monitoring the effect of different aquaculture practices on sediment prokaryote (Archaea and Bacteria) communities. The effect of initial fish (gilthead seabream Sparus aurata) stocking density on the structural diversity of prokaryote communities of earth ponds bottom sediments was evaluated using PCR‐DGGE after a 5 month grow‐out period. An identical approach was used to monitor the effect of supplying different fish feeds [commercial feed (CD) versus an ecofeed (ECO)]. One additional variable was the use of copper sulphate (CuSO4) as an algicide in some of the experimental rearing tanks. The statistical analyses of prokaryote community profiles showed that the presence of fish in earth ponds significantly influenced the structure of sediment prokaryote communities, when compared with earth ponds without fish, independently of the stocking density. Our results also indicated that the structure of the prokaryote communities of earth ponds supplied with the ECO feed shared a strong similarity with that fed CD. Curiously, the use of CuSO4 in ponds receiving the ECO feed promoted significant differences on the structural composition of the bacterial community, but not on the archaeal community. DGGE molecular fingerprints are suitable for fast evaluation of new management practices in food‐fish production on earth ponds by monitoring shifts on microbial communities in bottom sediments.  相似文献   

5.
Bacterial community and abiotic environmental parameters in twelve freshwater aquaculture ponds were analysed. According to the major component of stocked animals, the ponds were grouped into four types: black carp Mylopharyngodon piceus, largemouth bass Micropterus salmoides, yellow catfish Pelteobagrus fulvidraco and pearl mussel Hyriopsis cumingii ponds. Each type of pond was stocked with three species of Chinese carps (silver carp, bighead carp and gibel carp) to form a unique mode of fish polyculture or mussel–fish integrated culture. The bacterial composition was identified using 16S rDNA sequencing. Totally, 3701 and 11 150 operational taxonomic units (OTUs) were identified from the water and sediment samples respectively. The number of OTUs, abundance‐based coverage estimator, Chao1 index and Shannon diversity index were lower in the water column than in the sediment, suggesting that diversity and stability of bacterial community were higher in the sediment. In the water column, Proteobacteria, Actinobacteria and Bacteroidetes dominated at the phylum level, and 26 dominant genera were identified. In the sediment, Proteobacteria, Chloroflexi, Bacteroidetes, Acidobacteria and Nitrospirae dominated at the phylum level, and 25 dominant genera were identified. Bacterial compositions between the ponds with different aquaculture modes were similar at the phylum levels, but varied at the genus levels. The bacterial composition in the ponds was correlated with hardness, ammonia and total nitrogen in the water column. This study indicates that the type of aquaculture mode is a factor regulating the microbial community, which provides an insight towards microbial management through probiotic manipulation in pond culture.  相似文献   

6.
A participatory on-farm study analysed water and nutrient budgets of six low and four high water-exchange ponds of integrated agriculture–aquaculture (IAA) farms in the Mekong delta. Water, nitrogen (N), organic carbon (OC) and phosphorus (P) flows through the ponds were monitored, and data on fish production and nutrient accumulation in sediments were collected during a fish culture cycle. Results showed that, on average, only 5–6% of total N, OC or P inputs introduced into ponds were recovered in the harvested fish. About 29% N, 81% OC and 51% P accumulated in the sediments. The remaining fractions were lost through pond water discharges into adjacent canals. Fish yields and nutrient accumulation rates in the sediments increased with increasing food inputs applied to the pond at the cost of increased nutrient discharges. High water-exchange ponds received two to three times more on-farm nutrients (N, OC and P) while requiring nine times more water and discharging 10–14 times more nutrients than the low water-exchange ponds. Water and nutrient flows between the pond and the other IAA-farm components need to be considered when optimizing productivity and profitability from IAA systems.  相似文献   

7.
Abstract. The application of different combinations and levels of pellet formulated feed and chicken manure to ponds stocked with Macrobrachium rosenbergii (de Man) did not result in any significant differences in water quality, sediment chemistry, or benthic macroinvertebrate populations. Water chemistry data indicated that all ponds were eutrophic. Chlorophyll was strongly correlated with total nitrogen, but not with total phosphorus, suggesting that nitrogen limited algal biomass. There was evidence that added organic matter was rapidly decomposed and mineralized. The sediments appeared to act alternately as sources and sinks of nutrients, although there was least variation in sediment nutrient levels in the treatment which received manure only. Applied pelleted feed was directly consumed by the prawns. In the absence of pelleted feeds, macrobenthos appeared to limit prawn growth after 1 month of culture. Simple nutrient mass-balance equations indicated that the losses of nitrogen, phosphorus and carbon from the treatments receiving feed were not dissimilar to previously reported values in finfish culture.  相似文献   

8.
微生物群落是养殖池塘生态系统的重要组成部分,了解环境微生物群落结构和功能,可有针对性地进行养殖环境微生态调控。在不同季节采集尼罗罗非鱼（Oreochromis niloticus）和斑点叉尾鮰（Ictalurus punctatus）池塘水样,分析硝酸盐氮(NO3-N)、亚硝酸盐氮(NO2-N)、氨氮(NH4-N)、总氮(TN)和总磷(TP)等理化指标,利用Biolog-Eco微平板技术分析水体中微生物对各类碳源代谢的平均颜色变化率,利用高通量测序技术分析其菌群结构。结果表明,1月淡水养殖池塘水质和菌群结构不同于其他采样时间,养殖鱼类种类对池塘理化指标和微生物菌群结构影响不大。不同采样时间的池塘理化指标差异显著,同一采样时间不同养殖鱼类池塘的理化指标之间无显著差异。其中,1月尼罗罗非鱼池塘中的NH4-N含量高于其他月份,且显著高于4月和7月（P<0.05）;1月TP含量显著高于4月、7月和10月（P<0.05）。1月斑点叉尾鮰池塘的TP和NO3-N含量显著高于其他3个月份（P<0.05）。Biolog-Eco微平板技术检测到尼罗罗非鱼和斑点叉尾鮰池塘中的微生物群落对碳...  相似文献   

9.
In aquaculture, ponds with high loads of organic inputs, organic matter accumulates at the bottom over time. Uneaten feed, senescent phytoplankton and faeces are the principal sources of accumulated material, but quantifications are scarce. The sedimented organic matter develops into a flocculent layer in which different processes transform the material into inorganic forms. A better understanding of factors influencing organic matter accumulation/decomposition in the sediment is needed to better understand and manage the dynamics of nitrogen in fish ponds. In this study, the rate of mineralization of organic nitrogen and the nitrogen flux between the sediment and the water column were measured. Organic matter accumulation in fish ponds was quantified, and the data were used to construct, calibrate and validate a dynamic simulation model of organic matter deposition/decomposition in fish ponds. The accumulating material consisted of dead phytoplankton, fish faeces and uneaten feed. Through model calibration, the proportion of these materials in the total accumulated organic matter was determined. In the model, gross photosynthetic rate was estimated from an empirical relationship with feed input. After calibration, the model was validated using independent data. The model simulated well the concentrations of organic carbon and nitrogen in the sediments but it may be developed further, especially by considering the effects of resuspension.  相似文献   

10.
We evaluated the water characteristics and particle sedimentation in Macrobrachium amazonicum (Heller 1862) grow‐out ponds supplied with a high inflow of nutrient‐rich water. Prawns were subject to different stocking and harvesting strategies: upper‐graded juveniles, lower‐graded juveniles, non‐graded juveniles+selective harvesting and traditional farming (non‐grading juveniles and total harvest only). Dissolved oxygen, afternoon N‐ammonia and N‐nitrate and soluble orthophosphate were lower in the ponds in comparison with inflow water through the rearing cycle. Ponds stocked with the upper population fraction of graded prawns showed higher turbidity, total suspended solids and total Kjeldahl nitrogen than the remaining treatments. An increase in the chemical oxygen demand:biochemical oxygen demand ratio from inlet (4.9) to pond (7.1–8.0) waters indicated a non‐readily biodegradable fraction enhancement in ponds. The sedimentation mean rate ranged from 0.08 to 0.16 mm day?1 and sediment contained >80% of organic matter. The major factors affecting pond ecosystem dynamic were the organic load (due to primary production and feed addition) and bioturbation caused by stocking larger animals. Data suggest that M. amazonicum grow‐out in ponds subjected to a high inflow of nutrient‐rich water produce changes in the water properties, huge accumulation of organic sediment at the pond bottom and non‐readily biodegradable material in the water column. However, the water quality remains suitable for aquaculture purposes. Therefore, nutrient‐rich waters, when available, may represent a source of unpaid nutrients, which may be incorporated into economically valued biomass if managed properly.  相似文献   

11.
Bacterial communities in the water column and sediment of 12 commercial grass carp (Ctenopharyngodon idellus) farming ponds were analysed. At the same time, physical and chemical environmental parameters were measured, including secchi depth (SD), total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (CODMn). From 12 water samples and 12 sediment samples, 39 different ribotypes were detected with PCR‐denaturing gradient gel electrophoresis (PCR‐DGGE). The ribotype richness showed that bacterial species in the water column differed among these ponds, and the result of sequencing further revealed the dominant and common bacterial species. In total, 32 bacterial species belonging to seven phyla (Proteobacteria, Bacteroidetes, Actinobacteria, Cyanobacteria, Acidobacteria, Fibrobacteres and Fusobacteria) were identified. Ordination via canonical correspondence analysis (CCA) on the DGGE data and environmental parameters indicated that the composition of bacterial community was significantly influenced by SD.  相似文献   

12.
为了揭示池塘种植莲藕对沉积物养分吸收及其养分转化相关酶的作用效果,将基本情况完全相同的黄颡鱼养殖池塘分为植藕组（Tf）和非植藕组（CK）,观察两组池塘在黄颡鱼苗种培育过程沉积物中养分和4种酶（脲酶、磷酸酶、蛋白酶、蔗糖酶）活性的变化特征。结果表明,与CK相比,Tf沉积物中的TN、NH4+—N和NO3-—N在莲藕苗期后均显著降低,在莲藕休眠期分别降低了8.5%、54.1%和52.7%,其中NH4+—N减少是沉积物中TN降低的主要原因;从莲藕苗期至花果期TP明显下降,最大降幅达22.6%;苗期后有机质开始显著降低,休眠期相较未植藕池塘降低8.4%。对两组池塘而言,沉积物的酶活性均呈现先增加后降低的变化趋势,Tf沉积物中4种酶的平均活性均高于CK,酶活性的差异在莲藕苗期和休眠期达显著水平（P < 0.5）。分析表明,4种酶之间存在着显著正相关关系（P< 0.5）,脲酶、磷酸酶和蔗糖酶活性与沉积物中NH4+—N的含量呈显著负相关,蛋白酶活性与沉积物中NO3-—N的含量呈显著正相关。  相似文献   

13.
The antimicrobial sulphamethazine is widely used in aquaculture for the prevention and treatment of bacterial diseases. Residues of sulphamethazine have been detected in aquatic environments and in edible tissues of aquaculture fish and shrimps at relatively low, but detectable concentrations. Detailed information on the environmental fate and pharmacokinetics of sulphamethazine in aquaculture species is essential to predict possible ecological risks and to provide recommendations on appropriate dosages and withdrawal periods. In this study we investigated the distribution of sulphamethazine in water and sediments of Fenneropenaeus chinensis shrimp ponds treated with 50, 100 and 150 mg kg?1·bw of sulphamethazine for 5 days and measured the uptake and elimination dynamics of sulphamethazine in different shrimp organs and tissues. Results of the HPLC analysis showed highest sulphamethazine concentrations in shrimp tissues, followed by sediments and water. The rank order of the mean concentrations of sulphamethazine in shrimp tissues and organs was hepatopancreas> plasma≈ stomach> muscle≈ gill≈ intestine> carapace. The results also demonstrated a significant dose‐dependent accumulation of sulphamethazine in the different biological and environmental compartments. Sulphamethazine decreased gradually with the time in all of the three compartments. The mean half‐life of sulphamethazine in sediment and water was 2.15 and 2.17 days respectively. A withdrawal period of 10 days or more is proposed for F. chinensis orally treated with sulphamethazine in order to meet the current food safety standards.  相似文献   

14.
为探讨菌藻调控技术、底质改良技术及投饵区微孔增氧技术对异育银鲫养殖池塘底泥微生物群落结构多样性的影响,在江苏大丰地区选择3口总面积约42.93hm~2的异育银鲫精养池塘实施以上技术,同时两口总面积约30hm~2的池塘作为对照池,采用PCR-DGGE方法比较分析4—7月池塘底泥中的细菌多样性。试验结果显示,试验塘底泥细菌多样性指数为3.15~3.52,明显高于对照塘的2.20~2.74,表明了三大技术的实施有利于提高底泥中细菌多样性指数,同时底泥菌群多样性指数的平均值与异育银鲫的损失率呈正相关,一定程度上反应了三大技术的联用有利于提高精养池塘生态稳定能力,间接增加养殖效益。  相似文献   

15.
为客观综合评价养殖水体质量,利用熵确定水质指标权重,结合物元分析理论及贴近度的概念,构建养殖水质复合模糊物元模型,对2015—2019年监测的上海地区635批次养殖水样进行地表水环境质量等级分类.水质监测结果显示,池塘水体的pH、总磷、高锰酸盐指数、As(砷)和叶绿素a平均含量显著高于引水河道的(P<0.05),硝酸盐...  相似文献   

16.
A participatory on-farm study was conducted to explore the effects of food input patterns on water quality and sediment nutrient accumulation in ponds, and to identify different types of integrated pond systems. Ten integrated agriculture-aquaculture (IAA) farms, in which ponds associate with fruit orchards, livestock and rice fields were monitored in the Mekong delta of Vietnam. Pond mass balances for nitrogen (N), organic carbon (OC) and phosphorus (P) were determined, and pond water quality and sediment nutrient accumulation were monitored. Data were analyzed using multivariate canonical correlation analysis, cluster analysis and discriminant analysis. The main variability in pond water quality and sediment nutrients was related with food inputs and water exchange rates. Water exchange rate, agro-ecological factors, pond physical properties and human waste input were major variables used to classify ponds. Classification was into: (1) low water exchange rate ponds in the fruit-dominated area, (2) low water exchange rate ponds in the rice-dominated area receiving homemade feed, and (3) high water exchange rate ponds in the rice-dominated areas receiving wastes. Pond water exchange rate was human-controlled and a function of food input patterns, which were determined by livelihood strategies of IAA-households. In the rice-dominated area with deep ponds, higher livestock and human wastes were found together with high water exchange rates. In these ponds, large organic matter loads reduced dissolved oxygen and increased total phosphorus concentrations in the water and increased nutrient (N, OC and P) accumulation in the sediments. In the rice-dominated area with wide ponds, higher homemade feed amounts were added to the ponds with low water exchange rate. This resulted in high phytoplankton biomass and high primary productivity. The contrary occurred in the fruit-dominated area, where fish were grown in shallow and narrow ponds, receiving more plant residue which resulted in lower phytoplankton biomass and lower sediment nutrient accumulation.  相似文献   

17.
Sedimentation and Resuspension in Earthen Fish Ponds   总被引：5，自引：0，他引：5  
Resuspension of particles from pond sediment into the water column may be an important nutrient transfer mechanism in aquaculture ponds. However, the magnitude of sediment re-suspension cannot be determined directly because sediment traps collect particles settling from the water column as well as those re-suspended from the pond bottom. We developed a dilution analysis method to differentiate the magnitude of the two particle source fluxes based upon the concentration of soil-derived elements (Si, Al, and Fe) and water-derived elements (C, N) in material collected by sediment traps placed in earthen ponds. Estimated organic C sedimentation from feed residues and algae was compared with trapped organic C as an independent and approximate measure of resuspension. Resuspension fluxes based independently on analyses of three soil-derived elements and on the estimation of expected C sedimentation were similar and accounted for 60–90% of the total solids flux (121–2,676 g/m2 per d) in most ponds sampled. The proportion of total flux that was derived from resuspension in ponds stocked with common carp Cyprinus carpio and tilapia Oreochromis spp . was modeled as a hyperbolic function of fish size and density, with a threshold fish size of 200–300 g. Resuspension flux was conservatively estimated to be equivalent to the daily suspension of a few mm of the pond bottom. These results indicate that sediment resuspension is a major process in carp and tilapia ponds, suggesting that the exchange of nutrients between the sediment and overlying water is intensive.  相似文献   

18.
Ten water quality parameters were measured in influent and effluent water at 11 aquaculture facilities in Hawaii. The data were grouped into four categories based on the types of organisms cultured: freshwater fish, freshwater prawn, marine fish, and marine shrimp. Within each category, concentrations of most parameters were lognormally distributed and spanned one to two orders of magnitude. Geometric mean concentrations of suspended materials, total nitrogen, total phosphorus, and pigments were highest in effluent from freshwater prawn ponds and lowest in marine fish pond effluent. Nitrate/Nitrite and total ammonia concentrations were higher in fish pond effluent than in crustacean pond effluent. Parameter concentrations were generally higher in effluent than in influent water, with freshwater fish and prawn ponds exhibiting the greatest increases in suspended materials and pigments. In contrast, nitrate/nitrite concentrations were lower in effluent than in influent waters. These data provide a basis for analyzing the environmental impacts of warm-water aquaculture effluent discharges.  相似文献   

19.
This study examined the effects of organic enrichment on water column, sediments and macrofauna caused by a fish farm in the Mediterranean Sea. Samples were collected on four sampling campaigns over a one‐year cycle. Significant differences were found in the water column in dissolved oxygen, dissolved inorganic nitrogen, phosphate and total phosphorus concentrations between the fish farm and the control. The increase in the dissolved inorganic nitrogen and phosphate concentrations at the fish farm modified the stoichiometric ratios between nutrients, with silicate acting as limiting nutrient at the fish farm 11% more than at the control. Nevertheless, chlorophyll a concentration in the water column was higher at the control station, probably due to the fouling of the underwater fish farm structures. Significant differences were found in sediment concentrations of organic matter, total phosphorus and redox potential between the fish farm and the control. The Canonical Correlation Analysis indicated that organic matter, total phosphorus, redox potential and% of gravels accounted for 68.9% of the total variance in the species data. Changes were observed in macrofauna, with a decrease in number of species and up to a nine‐fold increase in abundance with respect to the control.  相似文献   

20.
Studies to determine suitable levels of intensification are essential for developing sustainable aquaculture. The objective of this study was to evaluate the quality of effluents discharged from ponds stocked with 10 (D10), 20 (D20), 40 (D40), and 80 (D80) postlarvae of Macrobrachium amazonicum/m2. Intake and effluent water samples were taken throughout a 5.5‐mo grow‐out cycle. In that study, twelve 0.01‐ha earthen ponds were stocked postlarvae with 0.01 g. Average water exchange rate was 15%/d; water was discharged from the bottom of the ponds. Prawns were fed a commercial feed with 38% crude protein according to their biomass (3–10%) and the concentration of dissolved oxygen (DO). In our research, temperature, turbidity, total suspended solids, conductivity, DO, pH, biochemical oxygen demand (BOD), chemical oxygen demand (COD), N‐ammonia, N‐nitrite, N‐nitrate, N‐Kjeldahl nitrogen, total phosphorus, and soluble orthophosphate were measured every 15 d throughout the experiment in the early morning (0630 to 0730 h). Turbidity was lower in D10 than in D20 and D40 and total phosphorus was higher in D80 than in D10 and D20. An analysis of principal components comparing treatments and intake water showed three groups: intake, D10 and a cluster of D20, D40, and D80. On the basis of the water characteristics found in our study it appears that the farming of M. amazonicum is likely to have a low environmental impact, at least up to a stocking density of 80 prawns/m2.  相似文献   

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