Conservation and Efficient Use of the Marine Biodiversity in the Ambient Sea of Kasiwajima Island : For the Promotion of community development -Approach form Biology and Social Sciences-

生物学方法：2001年至2002年，我们在龟和岛的Usironohama海滩附近使用水肺对鱼类进行了研究。研究区基质划分为3个子区；活珊瑚，死珊瑚和巨石。共观察到42科206种。比较三个分区的结果，可以发现明显的差异，许多鱼类栖息在活珊瑚区。研究了环境海水中一些环境参数和水质的季节和时间变化。从海水资料看，岛上的环境环境受少营养化黑潮的强烈影响。然而，在夏季，海底溶解有机氮（DON）的浓度增加，可能是由于珊瑚的生产和排泄。一些观测结果表明，相对富营养化的沿海水体对小潮的影响在退潮期更为显著。本研究的结果表明，在某种程度上，鹿和岛周围的环境随着季节和月亮的年龄而变化。社会科学研究：在kasasiwajima地区，人们世世代代从事渔业。但最近出现了一种全新的海上生意。这就是所谓的潜水店。他们的工作是指导和指导来自高松和冈山市的潜水员。估计了接受概率曲线，并计算了支付意愿的一些统计数据。因此，WTP总额为26.2亿~ 99.1亿日元。为了验证数据的可靠性，我们对投标函数进行了估计。我们发现被调查者的第一份报告具有可靠性，而第二份报告的可靠性较低。在此基础上，应用区域旅游成本法（ZTCM）对柏岛游憩效益进行了评价。我们在三个不同的假设下计算了三个估计值。

Biological Approach : In Kasiwajima Island, we conducted the research on fish faunae-using scuba from 2001 to 02 off Usironohama Beach. The substrates of study area were classified into three sub-areas ; live coral, dead coral and boulder. Two-hundred and six species belonging to 42 families were observed. Comparing the results among the three sub-areas, clear difference could be found, and many fish inhabited the live coral area. Seasonal and temporal changes in some environmental parameters and water quality were investigated in the ambient seawater. Judging from the data of seawater, environment ambient of the island was under strong influences bf oligotrophic Kuroshio current. In summer, however, concentrations of dissolved organic nitrogen (DON) increased in the bottom water, probably due to the production and excretion by corals. Some observation suggested that influences of relatively eutrophic coastal water were more significant in ebb tide period in the neap tide. Results obtained in the present study suggest that environments around the Kasiwajima Island changes, to some extent, depending on the season and the age of the moon.Approach from Social Sciences : In Kasiwajima region people have been engaged in fishery for generations. But recently there was born a quite new type of sea business. It is so-called diving shop. Their work is to guide and instruct diveres who came all the way Takamatsu, and Okayama city. I estimated acceptance probability curve and computed some statistic of Willingness to Pay (WTP). As a result, the value of aggregated WTP is 2.62 -9.91 billion yen. To verify the data reliability, we estimated bid function. We found the 1st presentation from respondents had reliability, but the 2nd one had less reliability. After that, we applied ZTCM (Zonal Travel Cost Method) to evaluate recreation benefit of Kashiwajima Island. We computed 3 estimates under 3 different assumptions.