【作者】 刘兴国；

【导师】 刘兆普；

【作者基本信息】 南京农业大学 ， 水生生物学， 2011， 博士

【摘要】 池塘养殖是我国水产养殖的主要形式和水产品供应的主要来源。据《中国渔业年鉴2010》资料,2009年我国有养殖池塘416.4万公顷,养殖产量1852.91万吨,占水产养殖总产量51.2%以上。我国有悠久的池塘养殖历史,是世界上最早开展生态养殖的国家,我国劳动人民创造的“桑基渔业”、“蔗基渔业”等生态模式和“八字精养法”等养殖技术,为世界水产养殖业做出了巨大的贡献。由于我国的多数养殖池塘建设于上世纪七、八十年代,目前普遍存在着养殖环境恶化、设施破败陈旧、坍塌淤积严重、污染严重、水资源浪费大等问题,同时由于一直采用传统的养殖生产方式,池塘养殖普遍还存在着养殖方式简单,生态、经效效益不高等问题,严重制约了池塘养殖业的可持续发展。池塘养殖生态系统是一个相对独立且完整的生态系统。影响池塘养殖的基础因素包括池塘朝向、深度、长宽比等；影响池塘水体生态的物理因子主要有太阳辐射、天气和气候、温度与分层、水文、水流等；影响池塘养殖的化学因子主要是水的组成、土质、盐度、pH值、碱度和CO2、硬度、酸度、有机物分解、氧化还原电位、氮、磷、硫等；影响池塘养殖的生物因子主要是池塘生态系统中种群、群落的作用关系。本文以江浙地区大宗淡水鱼类池塘养殖为主要研究对象,分别从池塘养殖污染、池塘生态、池塘生态工程化技术和生态工程化养殖系统及调控方式4个方面进行了研究,旨在为建立池塘生态工程化技术提供理论依据和技术参考。主要研究内容和研究结果如下：调查研究发现,目前养殖环恶化,江浙地区的多数河、湖水质在Ⅳ类水以上,已不适合养殖用水要求；池塘养殖水资源浪费大,传统大宗淡水鱼类池塘养殖的需水量在4～6.5 m3/kg鱼之间；养鱼池塘每年的TSS、CODMn、TN、TP、直接排放量约为2280 kg/hm2·a、101 kg/hm2·a、5.0 kg/hm2·a;8、9月份,大宗淡水鱼养殖池塘总氮、氨氮、硝氮、总悬浮物的平均浓度分别达到2.44mg/L、0.56mg/L、7.38mg/L,0.01 mg/L、165 mg/L以上；池塘底质土壤的总氮、总磷和有机质含量分别超过自然土壤6.9、1.5和3.9倍,底质沉积污染表现为氮素沉积>有机质沉积>磷素沉积；养殖排水和底质沉积污染是池塘养殖的主要污染形式。综合国内外氮、磷收支的分析方法,研究分析发现江浙地区大宗淡水鱼养殖的氮输入约为90.24 g/kg鱼,其中饲料、肥料和外源水的输入比例分别为80%、11%、9%；养殖水体排放氮为13.76 g/kg鱼,底质沉积氮为57.04 g/kg鱼,分别为养殖投入氮的15.2%和63.2%。传统大宗鱼类池塘养殖的磷收入为21 g/kg鱼,其中饲料磷82%、肥料磷9.5%、水源带入磷8%、降雨带入磷0.2%；水产品磷支出占总投入磷的45.2%,水体排放磷为1.1 g/kg鱼,占投入磷的5.3%和排放磷的9.7%；底质沉积磷为10.38 g/kg鱼,分别占投入磷的49.4%和排放磷的90.3%。调查分析发现,7～9月份上海地区大宗淡水鱼养殖池塘水体有藻类48种,浮游动物24种,底栖生物15种；其中浮游植物平均密度3.10×l07 cell/L,浮游动物平均密度为15.8 ind./L,底栖生物平均密度为1079 ind./L,平均生物量为475g/m2；浮游植物优势种群为蓝藻、绿藻和硅藻；浮游动物优势种类为萼花臂尾轮虫(Brachionus calyciflorus)、短尾秀体溞(Diaphanosoma brachyurum)和近邻剑水蚤(Cyclops vicinus);底栖动物优势种为方形环棱螺(B. purificata)梨形环棱螺(B. purificat)和长角涵螺(A. longicornis).7～9月份山海地区池塘浮游植物的Shannon Wiener指数(H’)变化范围在1.60～2.10之间,浮游动物的Shannon Wiener指数范围0～1.83,池塘水体叶绿素a浓度104.8±12.3μg/L,卡尔森营养状态指数(TSI)范围为65～86,Margalef多样性指数范围为1.0～10.4,底栖动物Goodnight修订指数(G.B.I)指数为0.30～0.88,生物学污染指数(BPI)为1.1。整体显示为中等富营养化状态。池塘藻类特征研究显示,池塘水体中的藻类有明显的季节变化、日变化和水层变化。藻类平均密度在冬、春季节最高,秋季最低；池塘水体中的藻类优势种一般为绿藻、蓝藻、隐藻和硅藻,但有明显的季节变化；不同藻类在不同时间内所占的比例不同。藻类密度与水体中的氨氮和有效磷浓度有直接关系,池塘水体中的氨氮最高值一般出现在夜间凌晨5：00阶段,最低值出现在17：00前后,有效磷的最高值出现在夜间凌晨1：00阶段,最低值出现在13：00前后,与水体的藻类密度呈负相关,反映了藻类对氮、磷的吸收状况。不同季节影响浮游植物的关键理化指标不同,水温、营养盐、pH等理化指标是影响水体浮游植物密度、种类等指标的主要影响因子。池塘水体的Ch1.a有明显的季节性变化规律,与水体的TP四季变化有较好的相关性,而与水体的TN和COD季节变化相关性不明显,反映养殖水体中的Ch1.a受P影响较大,藻类的主要限制性因子为P。小球藻在养殖系统中生长特征和对养殖的影响作用研究发现,在光强4500Lx,水温25℃条件下,小球藻在养殖水体内呈Lgistic方式增长,K值为2543×104,r值为0.5913,最大可持续产量(MSY)为375.91×104 cell/(mL·d),养殖系统内每106 cell/L小球藻的生产力为9.4 J/(L·d)。养殖水体的氮、磷浓度对小球藻的密度有影响作用,但对藻类生长周期无显著影响(P<0.05)；小球藻能够有效吸收养殖水体中的氮、磷等营养物质,对三态氮的吸收存在着差异；水温25℃时,罗非鱼幼鱼的自然密度制约作用点为4.47 g/L,小球藻能够减轻养殖密度制约作用,有藻养殖可提高罗非鱼苗的相对增重率37%以上,降低饲料系数4.1～45.8%,在养殖水体中培育小球藻可以改善水质,提高养殖效果。主要生态工程化设施构建和净化效果研究表明,生态坡对池塘养殖水体中总氮、总磷、COD的净化效率分别为0.27 g/h·m2、0.015 g/h·m2和0.94 g/h·m2；对氨氮、亚硝态氮的去除率分别为46%和65%；对养殖水体中叶绿素a的去除率为8.8%；利用池塘坡面构建生态水处理设施,具有净化养殖水体、和延长池塘使用寿命和节约土地的作用。在水流速度为0.061 m/s的情况下,生物包对养殖排放水体中氨氮、亚硝酸盐的净化去除率分别为19%和45.5%,对水体中氨氮、亚硝态氮的去除率分别为0.61 g/h·m3和0.133 g/h·m3。在利停留时间为0.75h的情况下,陶粒生化滤床对养殖水体中叶绿素a、总磷、总氮的去处率分别达到62%、3.7%、53.8%,去处效率分别为2.7 g/h·m3、0.07 g/h·m3和1.65 g/h·m3。在面积比1：3的情况下,生态塘对养殖排放水体体中氨氮、总氮、总磷、可溶性磷酸盐、BOD5、CODMn的去除率分别为19.8%、14.3%、29.6%、29.1%、21.3%和43.1%；生态塘与养殖鱼池的搭配比例约为1：3-7。在相同养殖状况下,普通生物浮床占5%、10%、20%水面的池塘水体TN的浓度范围分别为1.65～5.42 mg/L、1.62～3.13 mg/L、1.63～2.62 mg/L; TP的浓度范围为0.18～0.28 mg/L、0.17～0.26 mg/L和0.18～0.21 mg/L；综合分析认为,普通生物浮床的覆盖率不应超过池塘水面的20%。复合生物浮床具有生化、生物等净化功能,有较高的净化效率。在池塘养殖生物负荷量1 kg/m3情况下,占池塘水面8.5%的复合生物浮床即可满足养殖水体净化需要；复合浮床的净化效率与养殖密度、品种、滤料比表面积、曝气量等有关。生态沟的净化效果与植物生长密切相关,与温度有一定的关系；生态沟构建要结合植物生长习性、生境要求等,合理的空间布局和时间分布才能达到改善水质的效果。湿地植物选配和净化效果研究表明,湿地植物不仅能吸收去除水体中的营养盐,还能为基质微生物提供适宜的微生态环境。湿地植物选配宜选用本地生物量大且易栽培的物种,还要考虑其经济性和景观效果。对水鳖(Hydrocharis dubia)、睡莲(?)(Nymphaea tetragona)、伊乐藻(Elodea nuttallii)、黑藻(?)(Hydrilla verticillata)、金鱼藻(Ceratophyllum demersum)、水芹(Oenanthe Javanica)、芦苇(Phragmites australis)、鸢尾(Iris tectorum)、菖蒲(Acorus calamus)等水生植物的净化效果研究发现,不同水生植物对氮、磷、COD的吸收能力不同,生长周期也不同；选配湿地植物时,应充分考虑不同植物的生长特点,合理搭配,才能达到预期的净化效果；种植试验发现,水蕹、茭白；水葱、水烛、茭白、美人蕉、黄花鸢尾和再力花等适合江浙地区种植。莲藕、茭白等水生植物作为湿地植物具有良好的净化效果和经济性。实验发现,与传统种植方式相比,生态种植莲藕可使水体中的总氮、总磷和COD分别下降24倍、10.3倍和3倍；生态种植茭白可使水体中的总氮、总磷和COD下降2.3倍、3.3倍和5.6倍。每100公斤莲藕、茭白可吸收氮2.4公斤以上,同时还可以吸收土壤中40%左右的磷。生态工程化池塘循环水养殖系统研究表明,循环水养殖池塘中的总氮、总磷、COD指标分别低于2.18±1.09 mg/L、0.46±0.12 mg/L和9.0 mg/L,分别是对照池塘的52%、29%和73%,明显低于对照池塘(P<0.05)。循环水养殖系统中潜流湿地对养殖排放水中总氮、总磷和COD的去除率分别在52%～59%、39%～69%和17%～35%之间；生态沟渠对养殖排放水中总氮和总磷的去除率分别为18.5%和17%；生态塘对养殖排放水中TN、TP和COD的去除率分别为24.7%、27.1%和26.75%。与传统池塘养殖模式相比,生态工程化循环水池塘养殖系统可节约养殖用水63.6%,减少COD排放81.9%,有明显的节水、减排效果。循环水养殖系统养殖池塘中以绿藻为主,其中小球藻(Chlorella vulgaris)、色球藻(Chroococcus minutus)、小环藻(Cyclotella sp.)为优势藻,而对照池塘则以微囊藻(Microcystis)、平裂藻(Horizontal fracture)、丝藻(Ulothrix sp.)为优势种；潜流湿地和生态沟对藻类的去除率分别为75.9%和55.2%；表面流湿地和潜流湿地对叶绿素的去除率分别为58.3%和91.6%。生态沟渠、生态塘、潜流湿地和养殖池塘的组成比例应结合养殖品种、密度等特点,生态工程化设施的面积一般不超过池塘面积的20%。池塘水体理化指标变化规律及水层交换的影响作用研究发现,白天池塘水体中的溶解氧(DO)、温度、氧化还原电位(ORP)、pH等理化指标普遍高于夜间,最高值一般出现在光照最强的13：00左右,最低值出现在凌晨3：00～5：00,而氨氮、有效磷的变化则相反；不同水层的DO、pH和温度变化随水深而降低。水层交换具有实现水体上下交换,增加底部溶氧,改善氧债,激活底泥生态等作用,可有效地降低有害物质(如亚硝酸盐、氨氮、硫化氢、大肠杆菌等)的含量。综上研究表明,目前多数地区的养殖环境恶化,养殖水源已基本不适合养殖需要,沉积污染和排放污染是池塘污染的主要形式,养殖池塘的生物学特征反映了池塘的富营养化状态；养殖池塘水体中的藻类有明显的季节变化、日变化和水层变化,其变化与水体营养盐、光照、温度等因素有关；小球藻是池塘中主要的藻类,其种群状况对养殖影响很大,相关研究可为池塘生态调控提供依据；生态坡、立体弹性填料净化床、陶粒生化滤床、生态塘、生物浮床、生态沟渠等是主要的生态工程化设施,其净化效率各有特点；水生植物是生态工程化系统中重要的组成部分,合理的选配植物有助于建立稳定高效的系统；生态工程化池塘循环水养殖系统模式具有“生态、安全、高效”的特点,是改变传统养殖方式、提高养殖效果的有效途径,对池塘生态关键影响因子进行调控是实现高效养殖的发展趋势。更多还原

【Abstract】 Pond aquaculture is the main way of aquaculture in China, which is also the main source of aquatic product. According to the China Fisheries Yearbook of 2010, the area of aquaculture pond reached to 4,164,000 hm2 in 2009; and the production reached to 18,529,100 tons, which occupied above 51.2% of the total aquaculture production. The pond aquaculture in China has a long history, and China is one of earliest countries of the world to develop ecological aquaculture. The ecological aquaculture model of "fisheries based on mulberry culture", "fisheries based on sugarcane culture", and so on, and the "intensive aquaculture based on 8 kinds of aspects" culture technique, which was created by Chinese people, make a great contribution to the world aquaculture.As the Chinese ponds were mainly constructed during 1970s to 1980s, the problems of environmental degradation of aquaculture, old and ruined facilities, heavy collapse and sedimentation, heavy contamination and waste of water source and so on, are common. Meanwhile, as the pond aquaculture always used the traditional mode of production, the problems of simple mode in aquaculture, low ecological and economic efficiency, limit the sustainable development of pond aquaculture heavily.Aquaculture pond ecological system is a relatively independent and integrated system, in which the culture organisms are affected by the biotic and abiotic environment. The factors affecting pond aquaculture include pond’s orientations, depths, length-width ratios, and so on. The physical factors affecting it mainly include solar radiation, weather and climate, temperature and layering, hydrology and water current. The chemical factors affecting it mainly include the water composition, soil property, salinity, pH value, alkalinity and CO2, hardness, acidity, decomposition of organic matter, oxidation-reduction potential, nitrogen, phosphorus, sulphur, and so on. The biotic factors mainly contain the community and population of the pond ecosystem.This research was mainly carried on to the mass pond aquaculture of freshwater fish in Jiangsu and Zhejiang regions, from the 4 aspects of pond aquaculture pollution, pond ecology, engineering techniques of pond ecology and regulation and control of ecological engineering aquaculture system, to provide certain theoretical guidance and technical reference for establishing pond ecological engineering techniques. The main contents and results are as follows.The research results found that, the water quality of most rivers and lakes in Jiangsu and Zhejiang regions at present was in level IV or even worse, which was not fit for aquaculture, and water treatment is in need for aquaculture. The water requirement of traditional aquaculture is about 4-6.5 m3/kg fish. The direct discharge of TSS, CODMn, TN and TP of the pond was about 2,280kg/hm2·a,199 kg/hm2·a,101 kg/hm2·a and 5.0 kg/hm2·a, respectively. During August and September, the mean concentration of the total nitrogen, ammonium nitrogen, nitrate nitrogen and total suspended solids was above 2.44 mg/L,0.56 mg/L,7.38 mg/L,0.01 mg/L and 165 mg/L, respectively. The level of total nitrogen, total phosphorus and organic matter of the pond sediment was 6.9,1.5 and 3.9 times higher than that of natural soil, and the rank order of the sedimentation was nitrogen> organic matter> phosphorus. Water discharge and dredging were the main pollution discharge of pond aquaculture.According to the analysis methods on budget of the nitrogen and phosphorus at home and abroad, the results showed, the input of nitrogen of mass freshwater pond aquaculture in Jiangsu and Zhejiang regions was about 90.24 g/kg fish, in which the feed, fertilizer and external water source accounted to about 80%,11% and 9%, respectively. The nitrogen discharge of pond water and sediment was 13.76 g/kg fish and 57.04 g/kg, respectively, which accounted for 15.2% and 63.2% of the nitrogen input, respectively.And the input of phosphorus was 21 g/kg fish, while the input from feed, fertilizer, water source and precipitation was 82%,9.5%,8% and 0.2%, respectively. The aquatic product accounted for 45.2% of the total phosphorus input. The phosphorus discharge of pond water was 1.1 g/kg fish, which occupied 5.3% of the phosphorus input and 9.7% of the phosphorus discharge. The phosphorus sedimentation was 10.38 g/kg fish, which occupied 49.4% of the phosphorus input and 90.3% of the phosphorus discharge.The analysis found, there were 48 species of phytoplankton,24 species of zooplankton and 15 species of benthos in the pond. The mean density of the phytoplankton, zooplankton and benthos was 3.10×107 cell/L,15.8 ind./L and 1,079 ind./L, respectively. The mean biomass was 475 g/m2. The dominant algae were blue-green algae, green algae and diatom. The dominant zooplankton was Brachionus calyciflorus, Diaphanosoma brachyurum and Cyclops vicinus. And the dominant benthos was B. purificata, B. purificat and A. longicornis.The range of Shannon Wiener index (H’) of the pond phytoplankton and zooplankton during July and September was 1.60-2.10 and 0-1.83, respectively. The chlorophyll a content was 104.8±12.3μg/L. The range of TSI was 65-86, and the Margalef diversity index was 1.0-10.4. The range of Goodnight revised index (G.B.I) of benthos was 0.30-0.88, and the index of biology pollution (BPI) was 1.1, which showed the eutrophication of aquaculture ponds.Study on the variations of the pond algae and the relationship with nitrogen and phosphorus concentration. The results showed, there were obvious seasonal, diurnal and layering changes of the pond algae, and the mean density during winter and spring was the highest, while that of the autumn was the lowest. The dominant algae of the pond were green algae, blue-green algae, Cryptomonas and diatom, with obvious seasonal variations. The proportion of different algae occupied depended on different time.There were direct relationship between the algae density and the concentrations of ammonium nitrogen and soluble reactive phosphorus. The highest level of ammonium nitrogen occurred at about 05:00 a.m., and the lowest happened at about 17:00 p.m., while the highest level of soluble reactive phosphorus appeared at about 01:00 a.m., and the lowest level occurred at about 13:00 p.m., which was negative related to the algal density.. These showed the situation of assimilation of algae for nitrogen and phosphorus. The key physiochemical indexes affecting the phytoplankton depended on the seasons. Water temperature, nutrients, pH values were the main factors affecting the density and species of the phytoplankton. The changes of chlorophyll a depended on the seasons, and had good relationship with TP, however, its relationship with TN and COD was not significant. It showed that Chi.a was affected by the non-point source of P, and the main limitive factor was P.Study on the growth characteristics of Chlorella in the aquaculture system and its effects on the culture. The results found, under the situation of light density of 4500 Lx and water temperature of 25℃, Chlorella’s growth was in Logistic, and the K value was 2543×104, while r value was 0.5913. The maximum sustainable yield (MSY) was 375.91×104cell/(mL·d), and the Chlorella’s productivity of each 106cell/L was 9.4 J/(L·d). The nitrogen and phosphorus concentration affected the density of Chlorella, but it didn’t affect the algal growth cycle significantly (P<0.05). Chlorella can effectively absorb the nitrogen and phosphorus, and there were some differences between the absorbance for the three state of nitrogen. Under the water temperature of 25℃, the restriction density for juvenile Tilapia was 4.47 g/L, and Chlorella can alleviate the restriction. Compared with the aquaculture of no Chlorella, the aquaculture with Chlorella can improve the juvenile Tilapia’s, relative weight growth rate by above 37%, and reduce the food coefficient rate by 4.1%-45.8%. Culturing Chlorella in the aquaculture water can improve the water quality and culture effect.Study on the constructing techniques and purification affectfound thatbiological slope is a kind of wetland system between surface flow wetland and undercurrent wetland. The purification rate of biological slope on total nitrogen, total phosphorus, COD of the pond water was 0.27g/h·m2,0.015 g/h·m2 and 0.94 g/h·m2, respectively. And the removal rate of the ammonium nitrogen, nitrite nitrogen and chlorophyll a was 46%,65% and 8.8%, respectively. Building biological water treatment facilities using pond slope is not only good for purifying pond water, but also good for lengthening the pond life. And it is also good for saving land for building artificial wetland.Under the water current speed of 0.0061 m/s, the removal rate of the biological bag for ammonium nitrogen and nitrite nitrogen in the pond discharged water was 19% and 45.5%, respectively. And the removal rate for the pond water was 0.61 g/h·m3 and 0.133 g/h·m3, respectively.When the residence time was 0.75 h, the removal rate of the ceramsite biochemical filter bed for chlorophyll a, total phosphorus, total nitrogen reached 62%, 3.7%,53.8%, respectively. And the removal efficiency for chlorophyll a, total phosphorus, total nitrogen was 2.7 g/h·m3,0.07 g/h·m3,1.65 g/h·m3, respectively.The removal rate of ammonium nitrogen, total nitrogen, total phosphorus, soluble reactive phosphorus, BOD5 and CODMn of the biological pond for the discharged pond water was 19.8%,14.3%,29.6%,29.1%,21.3% and 43.1%, respectively. The area rate range of the ecological pond and traditional pondwas about 1:3-7.Study on the common biological floating bed found that the range of TN in the pond water was 1.65-5.42 mg/L,1.62-3.13 mg/L,1.63-2.62 mg/L, respectively, when the floating bed accounting for 5%,10%,20% of the aquaculture area. And the range of TP was 0.18-0.28 mg/L,0.17-0.26 mg/L,0.18-0.21 mg/L, respectively. Comprehensive analyses consider that the coverage rate of the common biological floating bed should not exceed 20% of the pond area.Complex biological floating bed can purify biochemically and biologically, whose purification rate was well above that of the common floating bed. Under the load capacity of 1kg/m3 of traditional mass freshwater aquaculture, the rate of complex biological floating bed accounted was about 8.5% of the pond area. The purification effect was related to the aquaculture density, culturing species, filter specific surface area and aeration amount.Usually, the purification effect of the ecological ditch is related to the vegetal growth and temperature. The construction of the ecological ditch should accord to the habit of the vegetal with combination of their habitat to proceed spatial and temporal distribution, which could improve the water quality and landscape construction in a long term. Study on the choosing vegetal for the wetland and purification effect of the aquatic vegetal. Wetland plants not only remove nutrients and pollutant, but also provide appropriate micro-environment for the substrate microorganisms. The general principle of choosing wetland plants was introduced, and the purification effect of aquatic plants, such as Hydrocharis dubia, Nymphaea tetragona, Elodea nuttallii, Hydrilla verticillata, Ceratophyllum demersum, Oenanthe Javanica, Phragmites australis, Iris tectorum, Acorus calamus, and so on. The purification effects of different combination of aquatic plants were analyzed, and the results showed the nutrients absorbance effect depended on different plants and their different growth cycle. According to their biomass, purification effect and whether easy for planting, Aponogeton lakhonensis, Zizania aquatic, Scirpus tabernaemontani, Typha angustifolia, Canna lily, Iris tectorum and Thalia dealbata, which were fit for Zhejiang and Jiangsu regions were chosen.The aquatic plant, such as lotus and Zizania aquatic, has good purification effect and economical efficiency for water. The results found that, compared with the traditional culture way, ecological culture of lotus can reduce the concentration of total nitrogen, total phosphorus and COD as high as 24 times,10.3 times and 3 times, respectively. And the reduction of total nitrogen, total phosphorus and COD of ecological Zizania aquatic culture water was as high as 2.3 times,3.3 times and 5.6 times, respectively. Each 100 kg lotus and Zizania aquatic can absorb 2.4 kg nitrogen and 40% of the phosphorus.Study on the system of ecological engineering water recirculation ponds aquaculture Found, the total nitrogen, total phosphorus and CODMn of the system of ecological engineering water recirculation ponds aquaculture was lower than 2.18±1.09 mg/L, 0.46±0.12 mg/L,9.0 mg/L, respectively, which was 52%,29% and 73% of the control pond and significantly lower than the control pond (P<0.05). The results found that, the removal rates of total nitrogen, total phosphorus and CODMn from the aquaculture emissions were 52%-59%,39%-69% and 17%-35%, respectively, in the constructed underflow wetlands; and the average removal rates of total nitrogen and total phosphorus were 18.5% and 17%, respectively, in the ecological ditch; and the average removal rates of total nitrogen, total phosphorus and CODMn were 24.7%, 27.1% and 26.75%, respectively, in the eco-pond. Compared to the traditional pond aquaculture, the ecological engineering water recirculation ponds aquaculture system can save as much as 63.6% water and reduce 81.9% COD emissions, which show significant effects on water saving and reducing pollution emission.The dominant algae of the system were green algae, including Chlorella, Chroococcus and Cyclotella, in the recirculation system. And the dominant algae of the control pond were Microcystis, Merismopedia and Ulothrix. The removal rate for algae of underflow wetland and ecological ditch was 75.9% and 55.2%, respectively. And the removal rate for chlorophyll of surface flow wetland and underflow was 58.3% and 91.6%, respectively. The area ratio of the ecological ditch, ecological pond, underflow wetland and aquaculture pond in the recirculation system should be on the basis of the culture species and density, and the area ratio of the ecological engineering facility usually shouldn’t exceed 20%.Study on the regular pattern of the physiochemical indexes of the pond and the effects of water layer exchange found that the DO, water temperature, ORP, pH in daytime was usually higher than that of the night, and the highest level was usually at about 13:00 when the light was the strongest, and the lowest level was at 3:00-5:00 a.m. However, the changes of ammonium nitrogen and reactive phosphorus were the opposite. The changes of DO, pH and water temperature reduced with the increase of the water depth.Water layer exchange can mix the water and increase the DO of the sediment and ameliorate oxygen debt, and activate the ecological effect of the sediment, and boost the remnant feed’s sedimentation, excrement decomposition and transformation, which can effectively reduce the harmful matters, such as nitrite nitrogen, ammonium nitrogen, hydrogen sulfide, Escherichia coli, suppress the rot of the water.The combined study showed that the discharge pollution was severe and the external water source was not fit for aquaculture. Sedimentation pollution and discharge pollution were the main form of pond pollution. And the pollution biology characteristics of the aquaculture pond showed the eutrophic state of the pond. The seasonal, diurnal and layering changes of the algae in the pond had great relationship with the nutrients’ content, illumination, and temperature. Chlorella was the dominant alga. The algal population composition had effect on the aquaculture. The relative study is helpful for providing theory of building ecological regulation.Ecological slope, stereoscopic elastic filler purification bed, ceramsite biochemical filter bed, ecological pond, biological floating bed, ecological ditch, and so on, are the main ecological engineering regulation facilities with special purification efficiency each other. Aquatic plant is one of the important parts of the ecological engineering system, and reasonable plants match is good for establishing stable and effective system. The model of ecological engineering pond recirculation aquaculture system is "ecological, safe and efficient", which is the effective way to change the traditional aquaculture way and improve the aquaculture benefit. Water layer and DO regulation is important regulation, which can save energy and feed, and improve the aquaculture effect and protect the safety of aquaculture.更多还原