摘要
通过系统分析近 2 0a来渤海中部海域 3a( 1 982～ 1 983,1 992～ 1 993,1 998～ 1 999年 ) 1 0航次的生态环境特征参数的变化 ,描述了变化趋势 ,初步讨论了各特征参数之间的相互关系。研究发现 ,近 2 0a来 ,渤海中部营养盐的浓度和结构 (N/P和Si/N)均发生了显著变化 ,表现为 :硝酸盐、亚硝酸盐、总无机氮持续增加 ,活性磷和硅显著降低 ,N/P值升高 ,Si/N值下降。N/P值 3a的五月和十月平均值分别为 1 64、5 2 4和 1 6 1 2 ,Si/N值分别为 1 3 2、3 87和 1 32。渤海中部海域氮限制的状况正在逐步改变 ,活性硅和磷从供给充分改变为硅和磷限制的临界 ;渤海营养盐结构若按此趋势演化 ,必将造成磷和硅限制。黄河口及毗邻海域磷很低 ,不是渤海磷的主要来源 ,而氮和硅主要由黄河输入 ,近几年来黄河断流减少了主要由风化过程产生的硅的入海量 ,而农用化肥的流失总量并未改变 ,这是造成上述变化趋势的主导因子。渤海赤潮近几年频发 ,硅的减少使硅藻生长受到了较大压力 ,从而间接地助长了甲藻的生长可能是一个重要原因。
The series data of nutrients and biological parameters in the central Bohai Sea for 20 years were reviewed. It is found that both concentration and relative content of nutrients were changed dramatically. The increase of nitrogen and decrease of phosphate and silicate led to the dramatically increase of N/P ratio and the decrease of Si/N ratio. The average ratio of N/P in May and October in the central Bohai Sea was increased from 1 64 in 1982～1983 to 16 2 in 1998～1999, but the average ratio of Si/N was decreased from 13 12 in 1982～1983 to 1 32 in 1998～1999. The situation of nitrogen limiting in the central Bohai Sea was gradually changing to that of relative lack of phosphate and silicate. The decrease of Yellow River flow into to Bohai Sea may be resulted in this change. These may limit the growth of diatom and thus promote the development of pyrrophyta if other conditions (e.g.temperature and hydrodynamics) were suitable. This may be the major factor for pyrrophyta red tide occued in Bohai Sea.
出处
《海洋环境科学》
CAS
CSCD
北大核心
2000年第1期15-19,共5页
Marine Environmental Science
基金
国家自然科学基金!重大项目资助课题 ( 49790 1 0 0 1 )
