草鱼复合养殖系统间隙水与上覆水中营养盐分布特征

Distribution of nutrients in the pore water and overlying water in Grass carp Ctenopharyngodon idellus polyculture system

中文关键词: 草鱼复合养殖系统  营养盐  上覆水  间隙水

英文关键词: Grass carp polyculture system  Nutrients  Overlying water  Pore water

中文摘要:

      采用陆基围隔实验法，于2009年6~10月调查并分析了草鱼复合养殖系统上覆水和沉积物间隙水营养盐（NH⁴-N，NO³-N，NO²-N，PO⁴-P）的时空分布及沉积物总氮（TN）、总磷（TP）和总碳（TC）含量的变化。结果显示，（1）草鱼复合养殖系统上覆水中NH⁴-N，NO³-N，NO²-N和PO⁴-P的含量波动范围分别为0.056~1.499、0.022~0.228、0.049~3.903、0.003~1.882 mg/L，间隙水中营养盐的平面分布中，NH⁴-N在总无机氮（DIN）中所占比例随着养殖时间的增加而增加，不同复合养殖系统的营养盐垂直分布特征不同，规律也不明显。（2）实验结束与实验开始时相比，沉积物中TN和TP含量无明显变化，但TC含量显著降低，以混养模式（GSC）的减少幅度最大。结果表明，在本实验条件下，草鱼、鲢鱼与鲤鱼复合养殖系统可有效降低养殖过程中有机物的积累，降低底层中潜在释放的NH⁴-N含量，是一种较为合理的草鱼复合养殖模式。

英文摘要:

      Spatial distribution of NH⁴-N, NO³-N, NO²-N and PO⁴-P in overlying water and pore water, and the change of TN, TP and TC concentrations in sediments in Grass carp Ctenopharyngodon idellus polyculture ponds were studied by means of land-based enclosure during June~October, 2009. The results showed that: (1) the concentrations of NH⁴-N, NO³-N, NO²-N, and PO⁴-P were 0.056~1.499, 0.022~0.228, 0.049~3.903, and 0.003~1.882 mg/L, respectively. The proportion of NH⁴-N in the DIN increased over time in the horizontal pore water. Different systems showed different vertical distribution of nutrients. (2) During the experiments, the concentrations of TN and TP didn't change significantly. However, the concentration of TC decreased significantly, especially in GSC. It is suggested that the accumulation of organic matter and potential release of NH⁴-N in the underlying water can be reduced effectively in Grass carp polyculture system. Therefore, this system might be applied in aquaculture.