The variability of ocean environment and phytoplankton along the 110°E meridian in the Southern Ocean

• Main Authors: 飯田 高大, 高橋 邦夫, 小達 恒夫, 福地 光男, Angela McGaffin, Ben Raymond, Takahiro Iida, Kunio T. Takahashi, Tsuneo Odate, Mitsuo Fukuchi
• Format: Conference Object
• Language: English
• Published: 2016
• Subjects: Antarctic; Southern Ocean; Antarc*
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=11071; http://id.nii.ac.jp/1291/00011019/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=11071&item_no=1&attribute_id=16&file_no=1

It is poorly understood that the multi decadal variability of marine environment in the Southern Ocean, however the very important factor for assessing ecosystem change in association with climate change. The marine environment has been measured coutinuously since 1965 on board the Japanese ice breakers Fuji and Shirase along almost every cruise track of the Japanese Antarctic Research Expedition (JARE) program. Hirawake et al. (2003) reported the long term variability of chlorophyll α concentrations in the sub-Antarctic frontal zone area (around 55°S). It is indicated that the incrasing trends of chlorophyll α and spreading of higher chl-α area to the north with 3-7 year cycles were found. In addition, we found that the stepwide increasing of chlorophyll α concentration in the surface layer (0-100m in depth) in 1999/2000 summer season. Relatively large bloom was observed from ocean color remote sensing data around polor front. The zooplankton species composition and population was changed in 1999/2000 season (Takahashi et al. Hosie et al., this symposium). The cause of stepwise increasing of chlorophyll α is not clear, but there might result in the ecosystem change in the Southern Ocean. 第32回極域生物シンポジウム11月30日（火） 国語研究所 ２階講堂