Oceanic Observation and Investigation for Ocean Thermal Energy Conversion and Deep Ocean Water Use in Coast of Kemejima Island

Abstract

In 2013, Okinawa prefecture had launched the ocean thermal energy conversion (OTEC) demonstration plant and been operated for about six years in Okinawa prefectural government deep seawater research center (OPDSRC), Japan. The variety of high-develop business utilizing the deep ocean water (DOW) advances in Kumejima island by applying in the aquaculture, agriculture, bath, drinking water and cosmetic products. And, eventually, the DOW industry becomes the biggest community in terms of economical impact in the island. Furthermore, an expected increase of DOW intake capacity for expansion of DOW usage and for introduction of OTEC. In general, the function of DOW is the annual low temperature stability, the clearness, and inorganic nutrient-rich; however, the vertical profile data of the nutrient is limited in the coast of Kumejima. In this paper, therefore, the authors measured the sea water temperature, salinity, and DO by CTD, and sampled in each depth in four locations of the Kumejima east side. The sampled seawater were analyzed the concentration of inorganic nutrients. This research clarifies the vertical profiles of the basic data that is necessary for the application and clarification of the potential of OTEC and DOW multiple utilization.