獐子岛养殖海域氮、磷的分布特征

Distribution features of nitrogen and phosphorus in Zhangzi Island maricultural area

中文关键词: 营养盐  营养盐结构  叶绿素  獐子岛  底播养殖

英文关键词: Nutrient  Nutrient composition  Chlorophyll  Zhangzi Island  Bottom mariculture

中文摘要:

      根据2005年4个季节的调查资料，研究了獐子岛养殖海区的氮、磷营养盐的季节变化及平面分布特性，重点分析了7月营养盐、叶绿素及环境因子的相关性，探讨了与底播养殖的可能内在联系。结果表明，溶解性无机氮、活性磷酸盐的平面分布和垂直分布较均匀，仅在7月，表底层的氨氮浓度及磷酸盐浓度存在显著性差异。根据氮磷摩尔比和浮游植物生长的阈值分析，在该海区氮、磷营养盐限制呈季节性交替变化，7月磷限制的潜在性较大，3月和5月氮限制的潜在性较大。尽管目前的养殖生产活动并未对该海区的营养盐浓度产生较大的影响或压力，但是，3、5和7月底层水的无机氮以氨氮为主以及贝类养殖密度较大的区域叶绿素浓度较低的现象，可能与养殖活动有关，应引起关注。

英文摘要:

      The distribution and composition of dissolved nutrients in Zhangzi Island maricultural areas were discussed based on the data collected in March,May,July and October,2005．The results showed that because of large current velocity,the horizontal distribution of nitrogen and phosphorous were symmetrical and there were no obvious stratification between surface and bottom water(except in July).The nutrient level of DIN and PO3-4 in the surveyed areas belong to oligothrophic state.Nutrient limitations were assessed according to the ratio of Nitrogen/Phosphorus(N/P) and the concentration threshold,results showed that the limiting nutrients may change with seasons.There was high potential for phosphorous limitation of the photosynthesis of phytoplankton in July and nitrogen limitation in March and May.Though this survey revealed that there was little effect or impact of mariculture on the environment,the nutrients structure had change somewhat.For example, in March, May and July, DIN were the major component of ammonia the bottom water,and the relatively low concentrations of chlorophyll usually found at the extensive bottom culture areas may all reflect the activity of mariculture,which needs further study in the future.