流沙湾海水中总有机碳的时空分布及其影响因素研究

摘要

于2008年2月(冬季)、5月(春季)、8月(夏季)和11月(秋季)对流沙湾进行了4次采样调查,研究分析了流沙湾海水中总有机碳的空间分布和季节变化特征,并探讨了TOC与温度、盐度、pH、叶绿素a和底泥TOC之间的相关关系.结果发现,在2008年度流沙湾海水TOC的浓度为0.992 ～ 5.437 mg/L,平均值为2.414 mg/L,呈现春季＞夏季＞秋季＞冬季的变化趋势,整个流沙湾海域海水TOC的平面分布相对比较均匀,表层稍大于底层.在内外湾分布上,冬、夏季节内湾TOC大于外湾,而春、秋季节外湾大于内湾;在垂直分布上,冬、夏和秋季表层大于底层,而春季底层大于表层;在地域分布上,冬、夏季节从流沙镇一侧海域到西联镇一侧海域逐渐减小,秋季变化趋势相反,春季时,两侧无明显变化.相关关系的分析结果表明,流沙湾海水TOC与温度、pH呈现出正相关关系,与温度的相关关系较为显著,与盐度则呈现不显著的负相关关系;与叶绿素a存在一定的相关关系,在叶绿素a浓度小于2.6μg/L,两者呈现正相关关系,而在叶绿素a浓度大于2.6 μg/L,两者呈现负相关关系;与底泥TOC呈现出了一定的正相关关系.%The total organic carbon (TOC) in the Liusha Bay was investigated in February (winter), May (spring), August (summer) and December (autumn) of 2008. The characteristic of temporal and spatial distribution of TOC in seawater was studied and the correlations of TOC with temperature, salinity, pH value, chlorophyl-a content and sediment TOC were analyzed. The result showed that TOC content values ranged from 0.992 to 5.437 mg/L with average of 2.414 mg/L), and TOC content changed with a trend of spring>summer>autumn>winter. In Liusha Bay, the horizontal distribution of TOC was relatively even and TOC content in surface water was a little higher than bottom water. The TOC content of inner bay was higher than outer bay in winter and summer, while reversed in spring and autumn. For the vertical distribution, TOC content of surface water was higher than that of bottom water in winter, summer and autumn, while reversed in spring. For the regional distribution, The TOC content gradually decreases from Liusha town to Xilian town in winter and summer, and contrary in autumn. However, there was no significant changes in TOC content from Liusha town to Xilian town in spring. The correlation analysis showed that the TOC content had positive correlations with temperature and pH value. The former one is very significant, The TOC content showed insignificant negative correlation with salinity and definite correlation with chlorophyl-a. The TOC content positively correlated to chlorophyl-a when the chlorophyl-a concentration was less than 2.6 ug/L, while it is reversed when the concentration was more than 2.6 ug/L. In addition, TOC of seawater showed positive correlation with sediment TOC.