凡纳滨对虾室内封闭式养殖水质变化与氮收支的试验研究

Experimental Research on Change of Water Quality and Nitrogen Budgets for Indoor Closed Culture Ponds of Litopenaeus Vannamei

采用模式Ⅰ(臭氧机、增氧机、净水网与复合微生物制剂等)与模式Ⅱ(增氧机、净水网、复合微生物制剂与漂白粉精等)开展室内凡纳滨对虾封闭式养殖试验,探讨了养殖池水质变化规律及氮收支状况。结果表明,在80d养殖过程中,两模式所调控的养殖试验池主要水质指标均控制在对虾生长的安全范围。其中以模式Ⅰ与模式Ⅱ分别调控水质的1号与3号试验池主要水质指标平均值为:pH分别为7.92与7.96,DO分别为6.43与6.37mg·L-1,TAN分别为0.517与0.558mg·L-1,NO2-N分别为0.396与0.318mg·L-1,异养菌总数6863与19cfu·mL-1,弧菌数分别为13456与25cfu·mL-1。两池单位水体产量分别为1.18和1.02kg·m-3。两试验池氮收支估算结果为:投入饲料氮分别占氮总输入94.6%与95.3%,水层与虾苗含氮共占5.4%与4.7%;水层氮(含排污水)占氮总输出50.7%与58.3%,其近似于通常泥底养虾塘水层与底泥含氮之和占氮总输出的比例,其次是收获对虾占氮总输出31.9%与25.3%,池水渗漏等损失输出氮量占氮总输出17.4%与16.4%。

Traditional shrimp farming has caused many environmental and economical problems, such as worsen quality of offshore waters, disease outbreak and production losses. In order to promote the development of shrimp farming industry, some new techniques and facilities were used in many countries in recent years to fit the demand of eeo-aquaculture. Combined biosecurity techniques were applied in this study such as ozone, water purge net, microbe, continuous aeration and water recirculating system to maintain suitable water quality and reduced nutrient releasing from shrimp culture ponds. This study was conducted for indoor closed culture ponds of Litopenaeus vannamei to reveal change of water quality and nitrogen budgets in experimental pond 1 using model I which was the combination of ozone applications, aerator, water purge net and microbe, and pond 3 with model I1 composing of aerator, water purge net, microbe and bleaching powder. The main water quality parameters in pond 1 and pond 3 were as follows respectively： pH 7.92 and 7.96, DO 6.43 and 6.37 mg ·L^-1, TAN 0.517 and 0.558 mg· L^-1, NO2-N 0.396 and 0.318 mg· L^-1. The results showed that the water quality were effectively controlled within safe range in both ponds with different models during culture period for 80 d. Bacteria and vibrio in pond 1 were only 6 863 and 19 cfu·mL^-1 for the high effection of ozone on the deactivation of bacteria and viruse, while that in pond 3 reached 13 456 and 25 cfu· mL^-1 without ozone. At the end of the experi- ments, the final biomass loads were 1.18 kg· m^-3 in pond 1 and 1.02 kg· m^-3 in pond 3 respectively. Feed contributed 94.6% and 95.3% of total nitrogen inputs in pond 1 and 3, while original water and juvenile shrimp provided 5.4% and 4.7% of total input nitrogen in both corresponding ponds. The major output of nitrogen（50.7% in pond 1 and 58.3% in pond 3 ） was culture water including effluent, which was similar to the ration of the nitrogen outputs of both culture water and sediment in outdoor shrimp culture ponds with mud sediment. 31.9% of total nitrogen output in pond 1 and 25.3% in pond 3 were transformed into harvested shrimp finally, while 17.4% and 16.4% of total output nitrogen in pond 1 and pond 3 were the results of water leakage and so on.