关键词: 网箱养殖, 沉积物, 氮, 时空变化, cage culture, sediment, nitrogen, temporal and spatial variations

Abstract: To study the characteristics on spatial and temporal variations of nitrogen in the sediments from cage culture area, the sediments collected from different cage culture area of Zhanghu reservoir bay were determined and analyzed monthly for the content of total nitrogen, ammonium nitrogen, and nitrate nitrogen from June 2016 to May 2017. The relationship between various forms of nitrogen in the sediments from different cage culture area was discussed. The results showed that the range of annual content of sediment total nitrogen, ammonium nitrogen, and nitrate nitrogen were 530.00～3570.00, 28.29～362.46, and 3.36～7.98mg/kg, respectively. Sediment total nitrogen and ammonium nitrogen were influenced obviously by seasons, but the season variation of nitrate nitrogen was not obvious. The results showed that the content of total nitrogen was higher in winter and lower in summer, while ammonium nitrogen was the highest in summer. There were spatial significant difference in the content of various forms of nitrogen of sediments from different cages culture area. The content of total nitrogen and ammonium nitrogen in sediments of high density cage culture areas were significantly higher than that of non-cultured areas. The average content of total nitrogen in the low-density cage culture areas was significantly lower than that of non-cultured areas, but the content of ammonium nitrogen and nitrate nitrogen were not significantly different from that of non-cultured areas. The correlations of all forms of nitrogen were different in the sediments of different cage culture areas, and the significant positive correlations (P<0.05) between contents of ammonium nitrogen and total nitrogen, as well as between contents of ammonium nitrogen and nitrate nitrogen were found.