封闭循环水养殖系统中池塘覆膜对水质的影响

Effects of covering membrane etange on water quality in a recirculating aquaculture system

2005—2010年,对天津市天祥水产有限公司封闭循环水养殖系统水质进行了检测。结果显示:养殖池塘是否覆膜、覆膜面积大小,均会使整个养殖系统中的总硬度(TH)、总碱度(AT)、NH3-N和PO4-P在时空上产生差异。时间上,它们年份间差异极显著(P<0.01);空间上,各采样点的AT和NH3-N差异显著(P<0.05)。覆膜使系统的TH和AT稳定性减弱,CV上升了166.5%～241.7%,这种情况在养殖中期尤为突出,但对NH3-N和PO4-P稳定性的影响并不明显。养殖系统中较大面积的覆膜(43.65%)对养殖池塘TH、AT和NH3-N稳定性的影响比非覆膜池塘的大,CV分别高出了75.9%、135.6%和21.6%;而小面积(19.2%)覆膜的养殖池塘相对非覆膜池塘稳定,CV分别降低了71.9%、41.5%和91.4%。导致它们间差异及稳定性变异的原因主要归结于覆膜影响了物质与土壤间的物质交换及其间的生物活性强度。

In 2005-2010,the water quality in the recirculating aquaculture system of Tianxiang Aquatic Co.Ltd was determined.The results displayed that the membrane and the area size of the membrane could change TH,AT,NH3-N and PO4-P of the whole aquaculture system in time and space.In time,there was extremely significant differences among different years（P〈0.01）;in space,all the sampling points had remarkable differences in AT and NH3-N（P〈0.05）.Covering membrane etange reduced the stability of TH and AT in the aquaculture system,CV increased by 166.5%~241.7%.This circumstance was particularly prominent in the medium of the culture process,but there was no obvious influence on the stability of NH3-N and PO4-P.For the indices of TH,AT and NH3-N,a large fraction of membrane covering in the aquaculture system（43.7%） was more variable than the non-covered etange（CV elevated by 75.86% for TH,135.6% for AT and 21.6% for NH3-N）;While the covered etange with a small covered area（19.2%）,was more stable than the non-covered etange（CV decreased by 71.9% for TH,41.5% for AT and 91.4% for NH3-N）.The reason for the above-mentioned differences in stability was attributed to the influence of membrane covering on substance interchange between the water and soil,as well as the biological activities within it.