南海南部浮游动物稳定同位素研究——碳稳定同位素

Stable carbon isotope of zooplankton in the southern South China Sea

文章分析了南海南部海域（108°~117°E;4°~12°N）春季和夏季不同粒径范围浮游动物碳稳定同位素特征。根据粒级将浮游动物分成三组,分别是〉500μm组（大型）、380~500μm组（中型）和180~380μm组（小型）。研究结果显示浮游动物δ13C值存在着显著的季度变化。夏季大型浮游动物δ13C平均值比春季高,而春季中型和小型浮游动物δ13C平均值比夏季高。单因素方差分析显示,各粒级浮游动物稳定同位素δ13C值并无显著性差异。广义加性模型分析结果表明大型和小型浮游动物δ13C值与对应粒径的浮游动物生物量没有明显的关系,与75m层盐度呈负相关关系（p〈0.05）;中型浮游动物与环境因素及生物量的关系不明显,显示水体垂直混合的季节变化对大型和小型浮游动物δ13C值有一定的影响。

The stable carbon isotopes of zooplankton based on size fractionation in the southern South China Sea during spring and summer 2013 were investigated. The zooplankton was divided into three groups according to size （〉 500 μm, 380-500 μm and 180-380 μm）. The mean δ13C value of macrozooplankton in summer was higher than that in spring, while meso- and micro-zooplankton showed opposite character. One-way ANOVA result showed no significance between size fractionated zooplankton groups. GAM analysis showed that both macro- and micro-zooplankton showed close relationship to seawater salinity at 75-m depth, while meso-zooplankton was not closely related to environment variables, indicating that vertical mixing also influenced stable carbon isotopes.