Evaluation of physical and ecological environments of a coral reef and its conservation strategy in a regional environmental system

1)对石垣县藤户岛和托多罗基河口地区由珊瑚礁、海草床、潮滩和红树林组成的综合生态系统进行了实地调查，弄清了水流特征、相关的热和物质输送、珊瑚群落新陈代谢等。2)我们建立了新的珊瑚和海草床冠层光学模型，并结合非线性逆估计方法，用于遥感图像分析。利用这些模型，我们成功地对珊瑚和海草床的冠层高度和密度进行了高精度的估计，并成功地进行了水深测绘。我们进一步发展了一种遥感方法，以探测沉积红壤对珊瑚礁的覆盖情况。3)通过对石垣岛、石垣岛和关城泻湖近20年来的20多幅陆地卫星图像的分析，发现了石垣岛和石垣岛之间的土地利用和植被覆盖的历史变化及其与生境特征…年际变化的关系在邻近的珊瑚礁中，珊瑚礁的覆盖率更高。4)通过使用装有GPS记录仪和移动电话的小型漂移器进行近地表颗粒跟踪、高频雷达测量以探测海面流的空间分布、相关区域不同位置的浮游生物网，我们揭示了珊瑚幼虫从喀拉玛群岛到冲绳岛西海岸的珊瑚幼虫扩散的礁间连通性。我们发展了一个多嵌套的近海模式，其中吸收了JCOPE模式的计算结果，分析了琉球群岛近岸地区的水流结构和幼虫的输送过程。利用该数值模拟模式，我们成功地再现了角马群岛至冲绳主岛西海岸的东流及其幼虫的输送，并阐明了东流产生的物理机制。我们进一步应用了数值模式，揭示了覆盖琉球群岛的更广泛区域的礁间连通性。5)为了阐明最近在琉球群岛暴发的荆棘海星(COTS)的种群动态，我们成功地建立了基于分子技术和遗传标记的野生COTS幼虫鉴定系统。我们还发现了在琉球群岛五个不同珊瑚礁采样的COTS的产卵高峰期，以及它们对当地水温的依赖。较少

1)Performing field surveys for integrated ecosystems comprised of coral reef, seagrass bed, tidal flat and mangroves at Fukido and Todoroki river mouth areas in Ishigaki Is, we have clarified characteristics of currents, related thermal and material transport, coral community metabolism and others. 2)We have developed new optical models for coral and seagrass bed canopies, combined with a nonlinear inverse estimation method, for remote sensing image analyses. With these models, we have succeeded in high-accuracy estimation of coral and seagrass bed canopy height and density and in bathymetry mapping. We have further developed a remote sensing method to detect the coverage of coral reefs by deposited red-soil. 3)Analyzing more than 20 LANDSAT images in the past 20 years at Ishigaki and Iriomote Islands and Sekisei Lagoon in between them, we have found historical change of land-use and vegetation cover of the land areas and its relationship with the inter-annual change of habitat charact … More eristics in the neighboring coral reefs like coral coverage. 4)With a comprehensive field in which we did near-surface particle tracking using small drifters installed with a GPS logger and a mobile phone, HF-radar measurement to detect spatial distribution of ocean surface current, plankton netting at various locations in the wide area concerned, we revealed the inter-reef connectivity in terms of coral larvae dispersal from the Kerama Islands to the west coast of main Okinawa Island. We have developed a multiple-nesting coastal ocean model, in which the computational results of JCOPE model are assimilated, to analyze the flow structure in the coastal areas of the Ryukyu Islands and the larval transport process. With this numerical simulation model we have succeeded in reproducing the eastward current and associated larval transport from the Kerama Islands to the west coast of main Okinawa Island and clarifying the physical mechanism of the generation of the eastward current. We have applied the numerical model further, revealing the inter-reef connectivity in wider regions covering the Ryukyu Islands. 5)To elucidate population dynamics of crow-of-thorns starfish(COTS), which has recently shown outbreaks in the Ryukyu Islands, we have succeeded in developing a larval identification system for wild COTS larvae based on molecular techniques and genetic markers. We have also found peak spawning periods of COTS sampled at five different reefs in the Ryukyu Islands and their dependence on the local water temperature. Less