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

1）对石垣岛吹户和轰河口地区的珊瑚礁、海草床、滩涂和红树林等综合生态系统进行了实地调查，明确了水流特征、相关的热量和物质输送、珊瑚群落代谢等。 2）我们开发了新的珊瑚和海草床冠层光学模型，结合非线性逆估计方法，用于遥感图像分析。借助这些模型，我们成功地高精度估计了珊瑚和海草床冠层的高度和密度以及测深测绘。我们进一步开发了一种遥感方法来检测沉积红土对珊瑚礁的覆盖范围。 3）通过分析过去20年中石垣岛、西表岛以及它们之间的石成泻湖的20多张LANDSAT图像，我们发现了陆地区域土地利用和植被覆盖的历史变化及其与邻近珊瑚礁的珊瑚覆盖等生境特征年际变化的关系。 4）通过使用安装了GPS记录器和手机的小型漂流器进行近地表粒子追踪、用于检测洋流空间分布的高频雷达测量、有关广泛区域的各个地点的浮游生物网等的综合领域，我们揭示了从庆良间群岛到冲绳本岛西海岸的珊瑚幼虫扩散方面的珊瑚礁间连通性。我们开发了多巢式沿海海洋模型，其中同化了JCOPE模型的计算结果，以分析琉球群岛沿海地区的水流结构和幼体运输过程。通过该数值模拟模型，我们成功地再现了东流和相关幼虫从庆良间群岛到冲绳本岛西海岸的运输，并阐明了东流产生的物理机制。我们进一步应用了数值模型，揭示了覆盖琉球群岛的更广泛区域的珊瑚礁间连通性。 5）为了阐明最近在琉球群岛爆发的棘鸦海星（COTS）的种群动态，我们成功开发了基于分子技术和遗传标记的野生COTS幼虫的幼虫识别系统。我们还发现了在琉球群岛五个不同珊瑚礁采样的 COTS 的产卵高峰期及其对当地水温的依赖性。较少的

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