凡纳滨对虾精养池养殖水体的富营养状况时空差异

Spatial and Temporal Discrepancy of Eutrophication of Water in Intensive Cultural Ponds for Litopenaeus vannamei

监测了凡纳滨对虾养殖全过程精养虾池养殖水体中溶解态无机氮(DIN)、溶解态活性磷酸盐(DIP)、水体的化学需氧量(COD)、pH、溶解氧(DO)、营养状态综合指数(E)等理化指标的变化,以及养殖后期水体中各理化因子的水平、垂直分布。结果表明:在凡纳滨对虾养殖过程中,DIN质量浓度为(0.093±0.076)～(1.736±1.134)mg·L–1,DIP质量浓度为(0.062±0.271)～(0.380±0.276)mg·L–1,COD质量浓度为(0.940±0.934)～(9.653±1.317)mg·L–1,E:(1.198±4.250)～(1267.537±68.534),富营养化程度随着养殖时间的增加逐渐增强,20d时各项指标均达到较大值,之后逐渐降低,到养殖后期又逐渐增强,营养状态综合指数(E)达到最大值;养殖后期,富营养化程度在水平方向随着靠近排污口的方向逐渐增强,营养状态综合指数(E):(343.230±1.659)～(2786.072±55.241),在垂直方向随着靠近池底的方向逐渐增强,营养状态综合指数(E):(2046.687±5.568)～(2789.524±7.166)。

The water in shrimp ponds for intensive culture of shrimp Litopenaeus vannamei was monitored in terms of DIN,DIP,COD,pH,DO and Nutritional Status Composite Index （ E） in the whole course of shrimp culture as well as horizontal and vertical distribution of physical and chemical indices at the late cultural stage. In the whole course of shrimp culture in the ponds the DIN was （ 0. 093 ± 0. 076） ～ （ 1. 736 ± 1. 134） mg· L^–1 ,DIP （ 0. 062 ± 0. 271） ～ （ 0. 380 ± 0. 276） mg·L^–1 ,COD （ 0. 940 ± 0. 934） ～ （ 9. 653 ± 1. 317） mg·L^–1 and the E （ 1. 198 ± 4. 250） ～ （ 1 267. 537 ± 68. 534） . The water eutrophication gradually increased as the shrimp culture went on,and all the indexes reached their peak values at the 20th day,and then the values gradually decreased but gradually enhanced at the late cultural stage when the E was maximum. At the late cultural stage the water eutrophication gradually increased horizontally towards the sewage outfall and the E was in the range of （ 343. 230 ± 1. 659） ～ （ 2 786. 072 ± 55. 241） ; the eutrophication gradually increased vertically near the bottom,and the E ranged from （ 2 046. 687 ± 5. 568） to （ 2 789. 524 ± 7. 166） .