Monitoring of coral calcification rate and CO2 concentration at coral reef.

(1)最重要的问题是珊瑚是从海水还是从空气中吸收或释放二氧化碳。在本研究项目中，对珊瑚的钙化研究表明，珊瑚能够有效地从海水中吸收二氧化碳，这是由于珊瑚细胞中存在Xozanthella。(2)珊瑚钙化的速度受白天光照强度的控制，这与Zoothanthella的初级生产量成正比。这表明，在珊瑚-游动藻类生态系统中，钙化过程和光合作用过程是相互交织的。珊瑚的钙化速率与初级有机产物(光合作用)的比值小于1(约1/3)，这对珊瑚吸收海水中的二氧化碳非常重要。因为钙化过程本身就是CO2的释放过程，而光合作用则是一个吸收CO2的过程。(3)观测了珊瑚礁中CO2浓度的分布和变化。观测到明显的CO2昼夜变化，类似于钙化研究的结果。这表明珊瑚生物也能有效地吸收二氧化碳。仍然存在的问题是，产生的有机物质在哪里运输、储存和分解。总结出珊瑚礁中的二氧化碳问题类似于公海中的二氧化碳问题。(4)建立了二氧化碳浓度监测系统。该系统能自动监测大气和海水中二氧化碳的变化。

(1) The most inportant question is whether corals uptake or release CO2 from sea water or from air" In this research Project, caltivation study of hermatypic corals revieled that coral can uptake the carbon dioxide from sea water effectively, awing to the coexistence of xoozanthella in the coral cells.(2) The rate of calcification by coral is controlled by the intensity of light intensity during daytime, which is proportional to that of primary production by zoothanthella. It is suggestited that calcification process and the photosynthesis process are kinked each other in the coral-zoothanthella ecosystems. The ratio of coral calcification rate to that of primary organic production(photosynthesis) is lower than unity(ca. 1/3), which is very important for the coral can uptake CO2 from sea water. Because calcification process itself is considered as CO2 release process,, on the other hand, photosynthesis is a CO2 uptake process.(3) The distribution and variation of CO2 concentration in coral reef was observed. Durnal variaton of CO2 was clearly observed, which is analogous to that of caltivation study. It is suggested that CO2 can also be uptaked by coral living organisms effectively. The remained problem is where the produced organic substances are trasported, deposited and the decomposed. It is generalized that CO2 problems in coral reef is analogous to that of open sea.(4) Monitoring system for CO2 concentration was established. This system can monitor automatically the CO2 variation both in air and in sea water.