This study is mainly composed of the following three approaches

　(1) Social anthropological approach: "Resource Management System and Response to Weather Disasters in Modern Times"

　First, after identifying the environmental characteristics of the three islets of Wale, Motu Koh, and Motu Kotawa through GPS mapping, the actual recharge of specific living resources such as taro, coconut palm, brackish water fish, coconut crab, seabirds, and material trees in the three resource management zones will be confirmed. Then, interviews with the Island Council, the Traditional Authorities Council (Kau Wowolo), and the Village Council (wuingāpule) of each village will be used to identify long-term and short-term strategies for environmental functional differentiation. In addition, we will use participatory observation to characterize the institutionalized resource management systems in each village, centering on neighborhood watch groups (pule) and food distribution organizations (tuanga kai), and identify the mechanisms that enable sustainable use of resources in normal times. In addition, we will examine the role of resource management systems in disaster mitigation, emergency response, and recovery in the event of weather disasters such as drought and tropical cyclones. In addition, we will focus on the case of the 2005 cyclone disaster and reconstruct how, when the islets were severely damaged, some residents extended their living world outside the atoll by migrating to Rarotonga in the Cook Islands, New Zealand, and Australia, and by encouraging material assistance to the existing migrants.

    (2) Historical Anthropological Approach: "The Construction of the Living World and the Reorganization of Social Groups in the Colonial Period"

    First, an analysis of historical data confirms the following historical events since the mid-19th century: the arrival of the London Missionary Society in 1857, the blackbirding of the island in the 1860s, the change of its status to a British protectorate in 1892, its entry into the copra industry at the end of the 19th century, its incorporation into the Cook Islands in 1901, the purchase of Nasau island, a single reef island located approximately 90 km southeast of Pukapuka atoll, by the Island Council in 1951, the deecline of copra industry in 1970s, etc. We will then identify the rapid changes in the political system, economic activities, social life, and population. Next, with the help of oral history interviews, we will describe the process of environmental functional differentiation of the three islets as a result of these changes, focusing on such events as the expansion of taro pits, the creation of coconut palm forests, the planting of oud tree species for seabird nesting, and the construction of an airstrip. We will also point out the transformation of the ownership and management of land and resources and the reorganization of social groups in the process, and clarifies how the three-village system and resource reserves were established, which today are often viewed statically as "traditions". In particular, the focus will be on the event of purchase of Nasau Island by the Island Council, and after clarifying its background and process, we will attempt to analyze it as an example of how the environmental functional differentiation was extended to neighboring islands outside the atoll and improved the environmental boundaries for the atoll residents.

    (3) Archaeological and Geographical Approach: "Topographic and Environmental Identification and Human Settlement History in the Prehistoric Period"

    First, based on the history of relative sea-level change since the middle Holocene based on altimetry and dating of detached water micro-atolls, topographic measurements and sediment dating will be conducted to clarify the state island formation process and geoscientific characteristics of each islet. Furthermore, excavations will be conducted on the three islets and Nasau island to search for traces of anthropogenic environmental modification, such as taro cultivation, through the identification of carbides and plant remains and secondary sedimentary layers, and to examine the possibility of prehistoric environmental functional differentiation. In addition, archaeology and geography will collaborate to analyze samples of reef-like blocks (tsunami stones/storm rocks) remaining on coral reefs, and detect event wave deposits caused by tropical cyclones to elucidate the history of meteorological disasters during the prehistoric period. If good core samples of micro-atolls are obtained, we will also analyze oxygen isotopes in coral annual rings to analyze paleoclimate such as El Niño and Southern Oscillation (ENSO) events.

    Finally, the results of (1), (2), and (3) will be summarized to diachronically reconstruct the actual process of the construction of the living world that the inhabitants of the far-remote atoll have developed to cope with fragility and vulnerability, and to disucuss the dynamics of both environmental functional differentiation and environmental boundaries.