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1.
桑沟湾养殖海域无机氮营养盐的分布与行为   总被引:4,自引:1,他引:4  
调查结果表明,桑沟湾IN的垂直分布均匀;该海域受人类频繁活动的影响,其平面分布和量值都有显著的季节性差异;NO3-N是该海域IN的主要存在形式。在海带养殖期间,IN和IN/IP比值始终处于低水平,其季节变异明显受到该湾初级生产水平的制约,故IN必然成为桑沟湾初级生产的限制因素,另外,海带养殖也加速了其养殖期间湾内水体中IN的物质循环速率。  相似文献   

2.
桑沟湾养殖海域的水环境特征   总被引:12,自引:0,他引:12       下载免费PDF全文
本文研究了桑沟湾养殖海域的水环境特征,并与10年前的历史资料作了比较。该湾各种化学指标的垂直分布均匀;受大面积高密度养殖影响,该湾水动力状况与10年前相比发生了明显变化,营养物质输送和海水自净能力降低;各种化学指标、初级生产力、营养状况及类型等平面分布和季节性变化都有更加显著的差异。在海带养殖期间,IN和IN/IP始终处于低水平,其季节变化明显受该湾初级生产力制约,故IN必然成为桑沟湾初级生产的限制因素。另外,海带养殖也加速了其养殖期间湾内水体中IN的物质循环速率。  相似文献   

3.
高产池塘养殖鱼细菌污染的季节变化   总被引:1,自引:0,他引:1  
陶妍 《水产学报》1996,20(1):92-96
高产池塘养殖鱼细菌污染的季节变化陶妍,骆肇荛(上海水产大学,200090)关键词养殖鱼类,高产池塘,细菌污染,鲜度,季节变化STUDIESONSEASONALVARIATIONINBACTERIALCONTAMINATIONOFFISHCULTURE...  相似文献   

4.
大鹏澳海水鱼类网箱养殖对水环境的影响   总被引:9,自引:3,他引:9  
根据2001~2002年对大亚湾大鹏澳海水鱼类网箱养殖海域水环境的监测资料,分析讨论了网箱养殖对水环境的影响。结果表明,该海域水环境质量较好,除夏季溶解氧(DO)和春季的硫化物浓度超第二类海水水质标准情况较严重外(超标率均为62.5%),其他水环境因子一般不超标。养殖区DO和叶绿素a(Chla)浓度均显著低于对照区(t-test,P<0.05),而NH4-N和PO4-P浓度则一般高于对照区,其他水环境因子的空间分布差异不大。海水CODMn、BOD5和硫化物主要与网箱养鱼生产季节性强的特点有关;而水温、盐度、透明度、悬浮物、DO和pH的季节变化主要受控于大亚湾亚热带季风气候,NO2-N、NO3-N、DIN、PO4-P和SiO4-Si等营养因子的季节变化主要受降雨和浮游植物的影响,Chla的季节变化则主要受水温和N:P比的影响,与网箱养鱼的关系并不明显。  相似文献   

5.
桑沟湾养殖海域营养状况及其影响因素分析   总被引:10,自引:0,他引:10  
桑沟湾营养现状调查结果表明,桑沟湾营养状况不仅受沿岸排放水的影响,而且大面积的海带和扇贝养殖对于营养盐的补充与消耗也有较大的影响,特别是在扇贝养殖区水域,富营养化水平较高。由N/P比值计算结果表明,从整个海湾看,冬季无机氮显得相对紧缺,而其他季节无机磷则显得相对紧缺。但从局部海域看,各季节扇贝养殖区无机磷显得相对紧缺。而在扇贝和海带混养区的1月,以及在海带单养区养殖海带期间的1月和4月无机氮显得相  相似文献   

6.
养殖水环境中氮的循环与平衡   总被引:13,自引:1,他引:13  
养殖水环境中,由于人为的介入和影响。使得水体中氮的各种形态转化和循环过程中发生了改变。笔者详细地介绍了养殖水环境中氮的各种存在形态,及其相互之间的转化和循环过程,同时总结了前人研究和提出的各种养殖水环境中氮的物质平衡模型,为优化水产养殖和保护水环境提供科学依据。  相似文献   

7.
养殖水环境中磷的循环与平衡   总被引:6,自引:0,他引:6  
详细地介绍了养殖水环境中磷的各种存在形态及其相互之间的转化和循环过程,同时总结了前人研究和提出的各种养殖水环境中磷的物质平衡模型,为优化水产养殖和保护水环境提供科学依据。  相似文献   

8.
2008年5月至2009年5月在阳澄湖中湖网围养殖区采集上、下层水样进行水质检测,并采用营养状态指数法对养殖区营养状况进行综合评价。结果显示,(1)养殖区营养盐的分布存在明显的时空变化,除了硝酸盐以外,所测指标均表现为养殖季节高于非养殖季节,高密度养殖区高于低密度养殖区,底层水高于表层水,说明高密度养殖造成氮磷的大量沉积。(2)高密度养殖区呈重度富营养状态,低密度养殖区也达到中度富营养。(3)2008年5月与2009年5月同期的水质监测数据显示,单季养殖的湖泊水质变化不明显。本研究表明,短期养殖对水质影响较小,但长期养殖则影响明显。网围养殖区富营养化日趋严重,目前已接近重度富营养状态,且磷污染较氮污染严重。  相似文献   

9.
獐子岛养殖海域氮、磷的分布特征   总被引:4,自引:1,他引:3       下载免费PDF全文
根据2005年4个季节的调查资料,研究了獐子岛养殖海区的氮、磷营养盐的季节变化及平面分布特性,重点分析了7月营养盐、叶绿素及环境因子的相关性,探讨了与底播养殖的可能内在联系。结果表明,溶解性无机氮、活性磷酸盐的平面分布和垂直分布较均匀,仅在7月,表底层的氨氮浓度及磷酸盐浓度存在显著性差异。根据氮磷摩尔比和浮游植物生长的阈值分析,在该海区氮、磷营养盐限制呈季节性交替变化,7月磷限制的潜在性较大,3月和5月氮限制的潜在性较大。尽管目前的养殖生产活动并未对该海区的营养盐浓度产生较大的影响或压力,但是,3、5和7月底层水的无机氮以氨氮为主以及贝类养殖密度较大的区域叶绿素浓度较低的现象,可能与养殖活动有关,应引起关注.  相似文献   

10.
桑沟湾养殖海域悬浮颗粒态有机碳的分布与特征   总被引:2,自引:0,他引:2  
孙耀 《水产学报》2000,24(4):329-333
根据1993年11月至1994年10月间9个航次的调查结果,讨论了桑沟湾养殖海域POC的分布与特征。结果表明,受海水养殖生产及风搅动等因素的影响,该湾的POC有显著的平面分布和季节变化。但其POC的垂直分布无显著性差异;该湾的POC与Chl-a之间呈正相关关系;与其它海域的估算结果相符,POC与POCB比值的较高值出现在有利于浮游植物生长的季节,反之,因温度降低或营养物质缺乏使浮游植物生长受限时,该比值降至最低点。该湾单位水柱下真光层中POC的τ值为29d。  相似文献   

11.
丁字湾养殖海域化学指标与营养状况的分析与评价   总被引:16,自引:1,他引:16  
本文根据1987年对虾养殖期间丁字湾海域的调查结果,以 IN、IP、COD和 DO为指标参数分析了该海域有机质和营养盐的污染状况和营养类型。分析结果表明,大面积对虾养殖排出的虾塘废水,能引起丁字湾海域有机质和营养盐的严重污染和富营养化,并且这种污染程度和营养类型有明显的季节变化。本文对丁字湾海域的赤潮能否形成也进行了预测。  相似文献   

12.
以自行设计的方法测定了对虾养殖环境中沉积物-水界面的营养盐扩散通量。结果表明,营养盐自底质向养殖水体的扩散贯穿于整个对虾养殖季节;该扩散通量的最大值出现在养殖后期的有机质污染区,即投铒区;在污染区,养殖后期的扩散通量大大高于养殖前期,但在非污染区却未见其随养殖季节的明显差异;污染区的扩散通量始终高于非污染区,且随养殖时间的推移,该差异逐渐增大。此外,还比较了新、旧虾塘之间的营养盐扩散通量的差异。初步探讨了底质溶出营养盐对对虾养殖环境的影响。  相似文献   

13.
对虾高密度养殖过程中水质的周期变化与分析   总被引:10,自引:0,他引:10  
杨世平  邱德全 《水产科学》2006,25(9):459-462
通过对对虾高密度养殖池中水质的连续监测,得出养殖水体水质污染状况及一般规律。养殖水体的污染主要是含氮废物的污染,在高密度养殖池养殖后期,养殖水体中氨氮首先达到峰值2.32m/L,随后亚硝酸盐的含量也迅速达到峰值0.773mg/L,在高密度养殖池中活性磷的含量较高,没有显示出明显的磷缺乏现象。  相似文献   

14.
采用低频率运转循环水处理系统(含粗滤器、臭氧仪、气液混合器,蛋白分离器、暗沉淀池等)联用池内设施(微泡曝气增氧机与净水网)开展凡纳滨对虾室内集约化养殖实验。研究了养虾池以水处理系统调控水质效果及氮磷收支。结果表明,养虾水经系统处理后,NO2-N(53.4%~64.5%)、CODMn(53.4%~94.4%)与TAN(31.6%~40.4%)被显著去除,有效改进虾池水质;养殖周期内未换水与用药,虾池主要水化指标均控制在对虾生长安全范围,7号实验池(100 d)与8号对照池(80 d)主要水化指标变化范围:DO分别为 5.07~6.70 mg/L和4.38~6.94 mg/L,TAN 0.248~0.561 mg/L和0.301~0.794 mg/L,NO2-N 0.019~0.311 mg/L和0.012~0.210 mg/L,CODMn 10.88~21.22 mg/L和11.65~23.34 mg/L。7号池对虾生长指数优于8号池(80 d虾病暴发终止),单位水体产量分别为1.398 kg/m2与0.803 kg/m2。氮磷收支估算结果:7号与8号池饲料氮磷分别占总收入:氮93.70%与92.37%,磷98.77%与99.09%;初始水层与虾苗含氮共占总收入6.30%与7.63%,磷共占1.23%与0.91%。总水层(含排污水)氮磷分别占总输出:氮56.45%与59.86%,磷53.26%与55.79%;收获虾体氮磷分别占总输出:氮37.07%与31.94%,磷21.37%与13.11%。7号池饲料转化率较高;池水渗漏与吸附等共损失氮磷分别占总输出:氮7.00%与9.34%,磷25.37%与31.10%。实验结果表明,虾池以低频率运转循环水处理系统联用池内设施可有效控制水质与虾病,具较高饲料转化率。  相似文献   

15.
ABSTRACT:   A pelagic bacterial community structure was examined in experimental intensive shrimp culture ponds that have a shrimp–mangrove complex aquaculture system, an extensive shrimp culture pond and a mangrove area in Thailand by denaturant gradient gel electrophoresis analysis of polymerase chain reaction amplified partial 16S rRNA genes. Bacterial community structure in the intensive shrimp culture ponds was distinguishable from that of the mangrove area. In the extensive shrimp culture pond, the bacterial community structure resembled that in the mangrove area, but bacterial abundance was as great as that in the intensive shrimp culture ponds. Among the intensive shrimp culture ponds, the bacterial community structure was different between a closed culture system and a shrimp–mangrove complex culture system. Moreover, the bacterial community structure in mangrove planted ponds was close to those in the intensive shrimp culture ponds when shrimp culture was conducted, but it was close to those in the mangrove areas without shrimp culture. These results suggest that intensive shrimp culture with shrimp feed input affects the bacterial community structures in pond water.  相似文献   

16.
The efficacy of a commercial microbial product was tested in commercial tiger shrimp, Penaeus monodon (Fabricius), ponds for one culture period in Kuala Selangor, Malaysia. Four ponds with replicates for treatment and control were used. The pond bottom was dried but the organic sludge was not removed as normally practised in pond preparation. The ponds were stocked with 15 post‐larvae at the rate of 31.m?2. Physical, chemical and biological parameters of the pond were analysed every 2 weeks during the culture period. Water quality parameters remained within the optimum range for shrimp culture except for ammonia‐nitrogen being significantly higher in control ponds and silica in treated ponds. Benthic organisms were not found in any of the ponds. The average counts of different bacteria were not significantly higher in treated ponds than control. Because of poor health, the shrimp were harvested earlier (72 days) than the usual 120 days. An average of 875.60 ± 67.00 kg shrimp ha?1 was obtained in treated ponds with a feed conversion ratio (FCR) of 1.57 ± 0.10 and survival rate of 42.35 ± 5.37% compared with 719.50 ± 130.94 kg shrimp ha?1, 2.99 ± 0.70 and 21.25 ± 3.26%, respectively, in control ponds. Neither the microbial product nor the frequent water exchange was effective in overcoming the problems caused by the poor pond bottom.  相似文献   

17.
二种微生物制剂对青虾池水质和生长的影响   总被引:1,自引:0,他引:1  
将二种微生物制剂施用于青虾养殖池,观察池塘水质的变化和对青虾规格及产量的影响,结果表明,施用微生物制剂后,池水的溶解氧、总磷增加,氨氮值下降,而COD、pH和总氮则没有明显变化和差异。试验池青虾的生长速度明显要大于对照池,说明微生物制剂可明显改善水环境,提高养殖青虾的产量和规格。  相似文献   

18.
WSSV has caused great losses to the global shrimp industry in recent years. This virus can infect shrimps asymptomatically. However, once the clinical signs are developed, mortalities can reach 100% in 3-10 days. PCR has been extensively used to detect WSSV in a specific and sensitive manner. Nested PCR is even more sensitive than single-step PCR and had been used for the detection of WSSV in asymptomatic populations. In this work, a detailed monitoring of WSSV by nested PCR in shrimp commercial ponds in Guasave County, State of Sinaloa, Mexico, is presented. Five ponds from two different farms were monitored for growth and presence of WSSV. At the beginning of the culture, ponds from both farms showed no or very slight WSSV presence. A 3-day period of rain occurred at both farms 10 and 14 weeks of culture for farms 1 and 2, respectively. At this time, WSSV was widely distributed in the shrimp populations of farm 1 according to nested-PCR data, although no visual symptoms were observed. In ponds of farm 2, WSSV was present at low level. However, the number of PCR-positive groups was drastically increased in both farms by nested and single-step PCR. Abrupt fluctuations in temperature and salinity were documented in farm 2 after the rain, which may have contributed to the increasing of viral load in the pond's shrimp populations. Twelve days after the rain period, estimated mortalities of 80% occurred in farm 1. Nevertheless, the study ponds at farm 2 culture continued normally for three more weeks and were harvested successfully (52% and 67% of survival for ponds 1 and 2, respectively). The removal of 40% and 50% of shrimp population 2-4 days after the raining period may have contributed to the thriving of the cultures. Analyses of the presence of WSSV in individuals of both sexes indicated that there is no preference for this virus to infect male or female shrimp. Also, no differences in weight were found between WSSV infected and non-infected individual shrimps, as well as nested-PCR positive against single-step PCR positive organisms. Nested PCR is more useful to monitor shrimp cultures than single-step PCR since it allows knowing how widely distributed the virus is in asymptomatically populations.  相似文献   

19.
封闭内净养虾技术试验报告   总被引:10,自引:0,他引:10  
为减少养虾业排污对海的污染,防止虾病传播,进行了封闭内净养虾技术试验。在全封闭条件下,采用在池内净化的措施,5个试验池平均亩产对虾65.19kg,比对照组增产70.61%;平均成活率为43.38%,比对照缄提高86.98%,投饵系数2.78,比对照组的4.48降低37.72%。  相似文献   

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