珊瑚与虫黄藻的共生是珊瑚礁生态系统最基本的生态特征, 虫黄藻光合作用效率直接决定着珊瑚的健康状况。本研究对海南三亚鹿回头珊瑚礁礁坪上5种典型珊瑚(澄黄滨珊瑚Porites lutea、丛生盔形珊瑚Galaxea fascicularis、标准蜂巢珊瑚Favia speciosa、多弯角蜂巢珊瑚Goniastrea favulus和伞房鹿角珊瑚Acropora corymbosa)共生藻的实际光量子产量Φ_PSⅡ进行了连续5日的现场监测, 并同时监测了该海域的7种环境参数(温度、盐度、溶解氧、pH、海水中二氧化碳分压pCO₂、辐射和潮位), 旨在探索鹿回头海域珊瑚共生虫黄藻光合作用的日变化规律及其调控因素。结果表明, 珊瑚共生虫黄藻光合作用效率和各环境参数都存在明显的日变化, 但共生藻光合作用效率主要受光合有效辐射强度(photosynthetic active radiation, PAR)所调控, 其次是温度和潮位变化。澄黄滨珊瑚的共生藻光合作用最易受到环境因素的影响。

Symbiosis of coral and zooxanthellae is the primary ecological characteristic of coral reef ecosystem, and photosynthetic efficiency of zooxanthellae decides the health of symbiont. The present study monitored the photochemical efficiency of zooxanthellae within tissues of five typical species of scleractinian corals, Porites Lutea, Galaxea fascicularis, Favia speciosa, Goniastrea favulus and Acropora corymbosa, in a Sanya fringing reef for five consecutive days, and recorded the environmental parameters of the area. Aiming at exploring the potential diurnal change of photosynthetic efficiency, we analyzed the pivotal factors that impede the photosynthesis of symbiotic algae. The results suggested that photosynthetic active radiation (PAR) determines the diurnal variation of Φ_PSⅡ, an indicator of actual photochemical efficiency. Temperature and tidal height also had prevalent influences on corals. In addition, Porites lutea showed the biggest amplitude of daily Φ_PSⅡ than the other four species.