夏季台湾海峡及邻近海域总有机碳含量的分布特征和影响因素

依据2006年7～8月对台湾海峡及邻近海域环境调查资料,分析了总有机碳(TOC)含量的空间分布特征,并讨论影响其分布的主要因素.结果表明,2006年夏季台湾海峡及邻近海域的TOC含量范围为0.54～3.68 mg/dm3,平均值为1.20 mg/dm3.TOC含量平面分布呈现由近岸向离岸逐渐降低、由北向南先降后升的趋势.在垂直方向上,随深度的增加TOC含量均值由1.35 mg/dm3降至1.07 mg/dm3,至底层时略有升高,为1.10 mg/dm3.TOC含量高值区主要出现在盐度32以内的区域,这表明径流输入是导致近岸TOC含量较高的主要因素,一方面通过直接输入,另一方面通过浮游植物繁殖间接增加,从而形成近岸TOC含量高值区.叶绿素a含量与TOC含量呈较弱的正相关,表明浮游植物活动对TOC的增加有一定贡献,海流运动以及浮游动物对叶绿素a的摄取可能是导致叶绿素a与TOC含量呈较弱正相关的主要因素.而在东山-南澳附近局部海域,上升流是影响TOC含量分布的主要因素.

Distribution of total organic carbon contents and influencing factors in Taiwan Strait and adjacent waters in summer

Based on the survey in Taiwan Strait and adjacent waters in July and August 2006, the spatial distribution of total organic carbon （TOC） is analyzed and factors influencing the distribution pattern are also discussed. The results showed that in Taiwan Strait and adjacent waters in summer of 2006, the TOC content was 0.54 - 3.68 rag/dm^3 and its average concentration was 1.20 mg/dm^3. The content of TOC decreased from nearshore to offshore while it first decreased from north to south and then increased. It also decreased with depth from 1.35 mg/dm^3 to 1.07 mg/dm^3 but slightly raised to 1.10 mg/dm^3at the bottom water layer. In the nearshore zone of salinity higher than 32 ,TOC concentration was high due to directly runoff input and indirectly the growth of phytoplankton. The chlorophyll a concentration was low correlated positively with that of TOC because of current movement, phytoplankton growth and zooplankton uptake. However, upwelling was the main controlling factor in sea waters along the coastof Dongshan and Nan＇ ao.