【摘要】 分析了近20a来大亚湾海域营养盐和叶绿素a含量的时空变化规律及其对生态环境的影响.结果表明:大亚湾海域水体中NH3N、NO3N、NO2N、PO4P、SiO3Si、DIN、叶绿素a的多年平均含量分别为1.73±0.89、1.55±0.86、0.30±0.25、3.57±1.55、0.33±0.35、22.03±9.40μmol/dm3和2.47±1.28μg/dm3.自1991年以来,水体中活性磷酸盐的含量有较大幅度的下降,溶解态的无机氮的含量则上升,活性硅酸盐的含量变化较小.大亚湾大部分水体属于贫营养水平,养殖海区水体属于中营养水平.大亚湾海域水体的N/P平均值为21.69±19.38.浮游植物的生长从过去的氮限制转变为现在的磷限制.大亚湾海域营养盐含量和结构的改变,已对该海湾生态系统产生了一定的影响,如浮游植物的小型化和渔获量的大幅下降等.更多还原

【Abstract】 Temporal and spatial variations of the nutrients and chlorophyll-a contents and their effects on the ecological environment in Daya Bay were analyzed. The results demonstrated that the average contents of ammonium, nitrate, nitrite, phosphate, silicate, dissolved inorganic nitrogen and chlorophyll-a were 1.73±0.89,1.55±0.86,0.30±0.25,3.57±1.55,0.33±0.35,(22.03±)9.40μmol/dm~3 and 2.47±1.28 μg/dm~3, respectively. Since 1991,the phosphate concentrations declined largely, in contrast, the dissolved inorganic nitrogen concentrations ascended, and the silicate concentrations did not change remarkably. The seawater quality in most of the water areas of Daya Bay belongs to oligotrophic level, and in the aquacultural water areas is in mesotrophic level. The mean ratio of (N/P) is 21.69±19.38 and the phytoplankton growth is controlled by phosphorus now instead of regulated by nitrogen in the past. The change of the nutrients concentrations and compositions in Daya Bay has influenced on the ecosystem of the Bay, e.g. the miniaturization of phytoplankton and the decline of fishery production to a great extent. incontrast,th nsdidnotchan更多还原