强降雨对粤西凡纳滨对虾养殖池塘微生物群落的影响

Influence of heavy rain on microbial community in Litopenaeus vannamei culture ponds in western Guangdong Province

于强台风"莫拉菲"环流云系带来的持续强降雨天气前后(2009年7月14日和7月28日),对广东省茂名市电白县凡纳滨对虾半集约化养殖土池的水样和泥样进行调查,研究施用微生态制剂和未施用微生态制剂的虾池水体及底泥中的异养细菌、弧菌和芽孢杆菌的变化情况,并利用BIOLOGECO微板对水体和底泥的微生物群落代谢变化进行探讨。结果发现,定期施用微生态制剂的虾池水体和底泥中的细菌数量和微生物群落功能在强降雨前后基本保持稳定;未施用微生态制剂的虾池在强降雨后,水体的弧菌数升高,Simpson指数和McIntosh指数显著降低(P<0.05),水体和底泥微生物群落对碳源的利用率变化明显。研究结果表明,与施用微生态制剂的虾池相比较,未施用微生态制剂的虾池在强降雨后,水体及沉积物环境波动变化明显,强降雨对其水域环境产生很大的影响。因此建议在对虾养殖过程中定期施用微生态制剂,并针对恶劣天气采取有效措施,以稳定虾池水体及沉积物的微生物生态。

The period from May to September is the rainy season in southern China coast,and also the typhoonprone season.Tropical storms and typhoons landing one after another often bring large amount of precipitation and form the heavy rain,which has a huge impact on aquaculture.After rainstorm or heavy rain,the water environment of aquaculture ponds is changed greatly.Furthermore,the risk of morbidity and mortality in shrimps may increase.The influence of severe weather condition on environment of shrimp pond is seldom reported.In the present study,the influence of heavy rain on microbial community in Litopenaeusvannamei culture ponds was explored.From July 18 to July 22,2009,the typhoon Mola Fei caused continuous heavy rain in western Guangdong Province.The water and sediment samples were collected in July 14 and 28,respectively,before and after this heavy rain.The samples were collected from a semi-intensive shrimp culture pond in which probiotics were periodically used.Samples were also collected from a identical shrimp pond without probiotics application as control.Variation of heterotrophic bacteria,Vibrio and Bacillus in samples were investigated.By using BIOLOG ECO microplate,microbial community metabolic changes in water and sediment were also studied.The results showed that the number of bacteria and microbial community function remained stable in water and sediment of the shrimp pond where probiotics were applied periodically before and after the heavy rainfall.In contrast,the number of Vibrio increased in water,while diversity index significantly reduced in sediment（P〈0.05）of the control pond.In addition,the carbon utilization of microbial community in water and sediment both obviously changed in the control pond.Due to heavy rain,water environment of shrimp ponds was affected greatly.To cope with severe weather,effective measures should be taken to stabilize environment and microbial ecology in both water and sediment.The probiotics,such as Bacillus,lactobacillus and so on,could be applied in shrimp ponds periodically.