闽北海域水体中溶解有机碳的时空变化及其影响因素

Distribution characteristics of dissolved organic carbon and influencing factors in the northern waters of Fujian

为探讨闽北海域水体中溶解有机碳(DOC)时空变化特征及其主要影响因素,于2015年8月、11月、2016年2月和5月对闽北海域环境进行调查,分析该海域DOC时空分布特征,并探讨DOC分布与Chl a、COD、AOU、营养盐、盐度等环境因子的关系。结果表明:2015~2016年闽北海域DOC的含量范围为0.32~2.78 mg/L,均值为1.19 mg/L;季节变化上,秋季>夏季>冬季>春季;空间分布上,整体呈现由近岸向远岸逐渐降低,由南向北逐渐升高的变化趋势,各季节略有差异。DOC与Chl a、COD以及盐度有较强的相关性,与AOU和营养盐的相关性不显著,不同季节影响DOC分布的主要环境因素存在一定差异。研究海域水体中DOC主要受浮游植物光合作用、陆地径流等因素影响,不同季节主要环境因素具有一定差异。

In order to explore distribution characteristics of dissolved organic carbon and influencing factors in the northern waters of Fujian,four oceanographic surveys were conducted in August and November 2015,February and May 2016. The paper analyzed the temporal and spatial distributions of DOC,and the relationship with environmental factors,including chlorophyll-a,chemical oxygen demand（ COD）,apparent oxygen utilization（ AOU）,nutrients（ N、P、Si）,salinity. The results showed that the DOC content ranged from 0. 32 to 2. 78 mg/L,with an average value of1. 19 mg/L in the northern waters of Fujian during the survey period of 2015 ~ 2016. DOC content was the highest in autumn,followed by summer,and lower value of DOC was in winter and spring. In horizontal distribution,the content of DOC decreased from nearshore to offshore,and gradually increasing from south to north,while the partial spatial distribution performed seasonal differences. DOC had a strong correlation with chlorophyll-a,COD and salinity,while no significant correlation with AOU and nutrient. There were some differences in the main environmental factors affecting the distribution of DOC in different seasons. DOC in waters of the study sea areas may be mainly affected by phytoplankton photosynthesis,land runoff and other factors,and the main influencing of environmental factors had differences in different seasons.