Abstract:Kueishan Island is located in the transition region between the temperate zone and the tropics. The island is bounded on the west by the Pacific Ocean. The famous North Pacific western boundary current, Kuroshio, flows passing the island on its eastern side, and forms an oceanic ecosystem. Beneath the Kuroshio lies a deep ocean ecosystem that extends to several thousand meters in depths. On the western side of the island is a neritic ecosystem. It receives fresh water from Hwan Hsi, Shuan Hsi, and Lanyang Hsi, and estuarine ecosystems develop near the river mouths. At certain times of a year, the seasonal intrusions of shelf seawater bring marine organisms of the East China Sea to Kueishan Island region. Recently, the discovery of a hydrothermal vent ecosystem near the island is apparently an exciting addition to the already highly diverse habitats in this region (Lee, 2001). This rich collection of microhabitats and ecological environments creates abundant and diverse marine biological resources, and makes Kueishan Island and its vicinity a valuable region for the establishment of a marine ecological conservation zone as well as for a multipurpose planning project for fishery activities.According to the study of Chang (2002), waters surrounding Kueishan Island is a marine environment with diverse biological resources, ecological habitats, and fishery resources. For the sustainable management and development of this region, he suggests establishing conservation zones and regulations for multipurpose utilization. However, information of species composition, distribution, ecology, and habitat characteristics in the vicinity of Kueishan Island is still sparse. As a result, detailed planning and legislation are faced with great difficulties. Based on these considerations, this study organizes related scientists in marine biology and ecology, and proposes to initiate a coordinate biodiversity study in Kueishan Island waters. Emphasis will be given to nitrogen fixing Teichodesmium and other phytoplankton, planktonic oligotrophic ciliates, zooplankton in the sound scattering layer, large crustacean animals, and larval fish. At the same time, this study will employ acoustic and imaging remote sensing, hydrographic investigation, and nutrient and heavy metal measurements to study the connections between biodiversity and distribution of marine organisms. Furthermore, information gathered from this study will be combined with those obtained from biodiversity hot spots along the northern coast of Taiwan to construct a complete Kueishan Island biodiversity data base. This data base will serve as a platform of basic knowledge for the design and legislation of marine conservation as well as multipurpose utilization.