Study of material flux from East Asian rivers into the ocean

本研究旨在探讨东亚河流对海洋生物地球化学循环的影响。最初，我们打算利用中国科考船“金星2号”，与中国科学院青岛海洋研究所的秦教授和其他科学家合作，研究长江口。这个项目的规划是通过通信进行的，并商定调查将于1995年11月开始。但是，中国同行通知我们，调查需要推迟。随后，首席调查员nozaki先生也来到了金岛，进一步讨论了详细方案，并对延中兴河进行了初步调查。但不幸的是，由于中国海洋科学政策的突然变化，我们无法获得中国政府（SOA：国家海洋局）的许可。因此，我们转向了第二个目标，并成功地在泰国的湄南河（Manum）上工作。1996年2月、7月和11月，通过与Manuwadi hungsprugs教授和Anond Snidvongs教授以及朱拉隆功大学的学生合作，每年进行3次实地抽样。值得注意的是，我们的团队可以以东南亚渔业发展中心（SEAFDEC）在Chao Praya河口的实验室为基础。利用一艘渔船在湄南河河口和泰国湾进行了水和沉积物取样。采用ICP质谱法测定了水样中稀土元素、铟等重金属含量。名古屋大学的k.o ohta也测量了沉积物中的有机质。部分研究结果已被《地球行星科学快报》接受发表。

The purpose of this study is to evaluate the influence of East Asian rivers in the biogeochemical cycling in the ocean. Originally, we intended to study the Yantze river estuary using a Chinese research vessel "Venus II" in colaboration with professor Y.Qin and other scientists of the Quindao Oceanographic Institution (Academica Sinica). Planning of this project had been made through correspondence and it was agreed that the survey would start in November, 1995. However, Chinese counter part informed us that the survey needed to be postponed. Then, Principal Investigater, Y.Nozaki also visited Quindao to discuss further the detail plan and to make preliminary survey on the Yanzte river. But unfortunately, due to abrupt change of policy in marine sciences in China, we could not get the permission of Chinese Government (SOA : the State of Ocean Administration).Therefore, we shifted to the second target and could successfully work on the Chao Praya (Manum) river in Thailand. Field sampling was made 3 times a year, February, July and November, 1996 through colaboration with Professors Manuwadi Hungspreugs, and Anond Snidvongs, and students of Chulalongkorn University. It is important to note that our party could be based on the laboratory of SEAFDEC (Southeast Asian Fisheries Development Center) at the Chao Praya river mouth. Water and sediment sampling was made by using a fishing boat in the Chao Praya estuary and the Gulf of Thailand. Heavy metals like rare earth elements and indium in the water samples were measured by ICP mass spectrometric method. Organic matters in sediments were also measured at Nagoya University by K.Ohta. Some of the results have been accepted for publication on the journal of "Earth Planetary Science Letters".