共查询到20条相似文献,搜索用时 156 毫秒
1.
2.
3.
4.
5.
6.
7.
湖北省漳河水库养殖场自1977年以来,因地制宜,进行鱼池种稗淹青培育大鱼种,成绩显著。如1983种稗57亩,长稗草54万斤,培育出3寸以上的鱼种1.87万斤,平均亩产328斤。下面是该场今年鱼池种稗养鱼一组场面。 相似文献
8.
养鱼的青饲料很多,受人们重视,较普遍的种植种类只有苏丹草,黑麦草及莪菜等。在诸多种草类中,我却喜欢种植农田害草-稗,稗草具有易种植,生长快,产量高,营养价值高等特点。 相似文献
9.
为了揭示无机氮和有机氮对沉积物磷释放的贡献,在武汉市青菱湖草型湖区和藻型湖区分别采集沉积物,进行添加不同形态不同浓度氮(0.5、2.5 g酪蛋白,0.02、0.2 g氯化铵)的培养实验。结果显示,培养结束时,草、藻型湖区沉积物加2.5 g酪蛋白的处理组上覆水中溶解反应性磷(SRP)浓度分别为对照组的64.88倍和5.61倍,而加氯化铵处理组与对照组上覆水中SRP浓度无显著差异;加氯化铵处理组上覆水溶解氧(DO)浓度分别为各自对照组的80%左右,而加酪蛋白处理组上覆水DO浓度分别为各自对照组的10%和4%;整个培养过程中,草、藻型湖区沉积物均为加2.5 g酪蛋白处理组的沉积物碱性磷酸酶活性(APA)稍高于其他处理组相应值,但无显著性差异;草、藻型湖区沉积物加2.5 g酪蛋白处理组磷平衡浓度(EPC0)分别为对照组的2.08倍和1.77倍;而加氯化铵处理组和加0.5 g酪蛋白处理组沉积物EPC0与对照组相应值无显著差异。研究表明,有机氮的富集会增加沉积物磷的释放,而无机氮对沉积物磷释放的贡献不大;有机氮对沉积物磷释放的影响是由形成厌氧的状态、胞外磷酸酶的分泌、改变沉积物磷吸附行为等多种因素综合作用的结果。 相似文献
10.
11.
桑沟湾海带养殖容量的研究 总被引:23,自引:5,他引:23
首次对桑沟湾的海带养殖容量进行了调查研究。采用了无机氮作为估算桑沟湾海带养殖容量的关键因子,通过无机氮的供需平衡估算海带养殖容量。结果显示,海底沉积物中释放的无机氮为该湾无机氮的主要来源,而由海水交换所带入的无机氮次之。海带生长期间海水交换周期为39d,比80年代中期延长了近1倍。桑沟湾在海带生长期间由海水交换、陆地径流、动物排泄和海底沉积物中释放所进入该湾的无机氮总供应量为1228t;而浮游植物 相似文献
12.
湖泊围养鱼类血液学指标的初步研究 总被引:21,自引:2,他引:21
本试验测定了185尾在湖泊围养区和池塘内体质健壮的草鱼、青鱼、团头鲂、鲢鱼、鳙鱼的血液,共取得红血球、血红蛋白、血糖、总蛋白、白蛋白、尿素氮、胆固醇、甘油三酯八项指标的1367个数据。经可靠性分析,除血糖指标的相对误差值略高于5%外,其余各项血液指标均值的相对误差,均达到生物调查实验要求。 相似文献
13.
In recent years, aquaponic systems have gained significant popularity as soilless agriculture systems for organic fruits and vegetables production with concomitant remediation of aquaculture effluent. Aquaponics is a potential sustainable food production system that integrates aquaculture with hydroponics in which nitrogen-rich effluent from the fish production is utilized for plant growth. Because nitrogen is one of the most important inputs in an aquaponic system, it is critical to investigate the nitrogen transformations in the system for enhanced recovery of resources. Since studies on nitrogen transformations and nitrogen utilization efficiency (NUE) in aquaponic systems have been very limited, this review critically examines the important fates of nitrogen from input to outputs (e.g., ammonia nitrogen generation, nitrification, nitrate assimilation and nitrogen loss) to improve NUE in aquaponic systems. Various factors affecting the nitrogen transformations are also discussed. Furthermore, an example of nitrogen imbalance between nitrate uptake and nitrate generation rates in an aquaponic system was demonstrated. This review aims to advance our current understanding of nitrogen transformations and outlines future research needs in aquaponic systems, a sustainable model for efficient water and nutrient managements, and food production. 相似文献
14.
Abstract. A simplified mass balance model was used to predict spatially averaged nitrogen and chlorophyll concentrations in Big Glory Bay, Stewart Island, New Zealand. The bay is used for salmon fanning and during January 1989 supported a dense bloom of Heterosigma alcashiwo which killed 600t of fish. Nutrient concentrations in the bay arc affected by inputs from bottom sediments, catchment run-off, rainfall, salmon farms and water exchange with Paterson Inlet (into which Big Glory Bay drains). The nitrogen model was calibrated using field data collected on 11–27 February 1988 and successfully predicted the mean nitrogen concentration of the bay during the 1989 bloom. Nitrogen concentrations in the bay were most affected by the nitrogen concentration in Paterson Inlet, which appears to vary year-to-year as a result of the incursion into Fouveaux Strait of highly fertile oceanic water. The marginal effect of the salmon farms was to increase the mean nitrogen concentration of Big Glory Bay by about 30%. The nitrogen model was combined with a logistic phytoplankton growth model to examine the effects of nitrogen availability and hydraulic flushing on phytoplankton yields (measured as chlorophyll a). The spatially averaged chlorophyll concentration of Big Glory Bay was reliably predicted during the 1989 study, when there was strong evidence that phytoplankton were nitrogen limited. The model indicated that nitrogen inputs from the salmon farms increased the mean chlorophyll concentration of the bay by about 33%. The model was less successful in predicting chlorophyll concentrations in February 1988 when phytoplankton growth was not restricted by nitrogen, but may have been controlled by zooplankton grazing or sedimentation (which were not included in the model). The use of mo re complex three-dimensional models is advocated to describe the observed'patchiness'in Heterosigma distribution. 相似文献
15.
城郊养鱼高产湖塘理化特点及生物相的分析 总被引:2,自引:0,他引:2
本文报导 1973年武汉市郊两个渔业高产湖塘的理化、生物环境特点,并分析了各类环境因素间的关系。在养殖季节中,湖水溶氧量通常在7毫克/升以上,总氮平均为2.63毫克/升,总磷平均为0.38毫克/升;浮游植物平均为2,199×10~4-3,080×10~4个/升,主要为硅藻,甲藻和绿藻等小型种类;浮游动物平均为39,200-74,318个/升,以原生动物和轮虫为主。文中提出了各类环境因素间相互关系的方程式,定量地描述了饵料生物丰度和氮、磷的关系。 相似文献
16.
一株高效脱氮菌株的分离鉴定及应用潜力分析 总被引:1,自引:1,他引:0
为了获得对虾养殖池塘中高效去除亚硝态氮和氨氮的菌株,采用富集培养分离的方法,从养殖水体中筛选得到1株去除亚硝态氮和氨氮的菌株,培养24 h后的去除率分别为96.17%和88.27%,编号为O-11。基于形态学、分子生物学及生理生化鉴定结果,明确了该菌株基本生物学特征以及可能的分类地位。分离菌株在20~30℃时有利于亚硝态氮的去除,而温度为20~35℃时对氨氮的去除效果较好;分离菌株在盐度小于30的环境中对亚硝态氮的去除能力受盐度变化的影响不大;在碱性环境中分离菌株对氨氮的去除能力较高。安全性检验可知,在菌浓度为10~5~10~8 cfu/mL的菌株O-11对凡纳滨对虾(Litopenaeus vannamei)是安全的,且在菌浓度为10~5 cfu/mL时能显著提高对虾的存活率,促进对虾生长。这说明,分离菌株O-11在水产养殖水体中有害氮脱除方面具有潜在的应用价值。 相似文献
17.
渤海海域营养现状研究 总被引:17,自引:1,他引:17
主要根据1992~1993年调查资料,分析了影响渤海营养状况的主要因子。结果表明:与历史同期调查结果相比,无机氮有所上升,无机磷下降较大,与国内外有关浮游植物对营养盐类的最低需求的适宜浓度相比,除冬季外,其他季节无机氮和无机磷均低于浮游植物所需要的最适浓度值。就N/P比值而言,仍低于海水的正常N/P比值,无机氮仍为渤海浮游植物生长繁殖的主要限制因子。无机磷除冬季外,也低于其浮游植物生长繁殖的最低浓度的下限,故认为无机磷也起一定的限制作用。 相似文献
18.
不同单养及混养海水实验围隔水化学的研究 总被引:4,自引:1,他引:4
1995年6~10月和1996年6~8月对不同单养和混养海水实验围隔的水化学研究结果表明:围隔中盐度、总氮、总磷和化学耗氧量(COD)在雨季前逐渐升高,进入雨季后降低;投饵养殖时围隔中磷浓度较低氮浓度较高,其中混养中国对虾和台湾红罗非鱼的围隔活性磷(PO4-P)浓度相对较高,混养对虾与菲律宾蛤仔的围隔氨氮(NH3-N)浓度较高,投铒兼酌情施肥养殖时围隔中氮浓度较低磷浓度较高,其中混养中国对虾与缢蛏 相似文献
19.
20.
鱼虾类暴发性疾病的中医学探讨 总被引:1,自引:0,他引:1
鱼虾类暴发性疾病的中医学探讨王鸿泰(中国水产科学研究院长江水产研究所)近年来鱼虾类暴发性流行病越来越严重,呈上升趋势,不少学者都认识到这些流行病与生态环境变化有密切相关,特别是多种细菌和病毒都在同一水环境中,如淡水中的呼肠孤病毒(Reovirus)、... 相似文献