南大洋インド洋セクターにおけるナンキョクオキアミに依存しない生態系に関する総合的研究

• Main Authors: 茂木, 正人, Masato, Moteki
• Language: English
• Published: 2013
• Subjects: Antarctic; Southern Ocean; Scotia Sea; Indian; Antarc*; Antarctic Krill; Euphausia superba; Sea ice
• Online Access: https://nipr.repo.nii.ac.jp/record/11775/files/S_MotekiMasato_2.pdf; https://nipr.repo.nii.ac.jp/records/11775

Ecosystem studies in the Southern Ocean have been intensively conducted in the Atlantic sector, where Antarctic krill (Euphausia superba) is a key species owing to its large biomass and geographically broad range. However, recent studies have indicated that an alternative energy pathway, a krill-independent food web, dominates in years and regions with lower abundances of krill in the Scotia Sea (Atlantic sector) (Murphy et al. 2007). In the Indian sector of the Southern Ocean, the geographical distribution of krill is limited to along the continental slope, and krill biomass is lower than that in the Atlantic sector. Thus, the krill-independent food-web is expected to be more important in the Indian sector. However, marine ecosystem studies in this region are still under development, and most research has focused on epipelagic waters. Therefore, the mesoand bathypelagic ecosystem of the Southern Ocean remains an unknown realm. In recent years, Japanese marine scientists have achieved progress in various scientific fields within the Southern Ocean, although only a few integrative science programmes have been undertaken in Japan. The scientific programme presented here aims to achieve a comprehensive understanding of the ecosystem in the Indian sector by combining results from individual disciplines that focus on physical and chemical processes, primary production, zooplankton, fish, and top predators. To accomplish this goal, we propose to investigate the following research topics: 1) Ecosystems under the sea ice and in the vicinity of the ice edge (including applications of acoustic techniques [see point 6 below]). 2) Epi- to bathypelagic ecosystems (including applications of acoustic techniques). 3) Early life history and survival strategies of larval myctophid fishes. 4) Biology of juvenile and adult myctophid fishes (monitoring abundance, biomass, food habits, and body size frequency as well as reproductive biology under the sea ice and in the vicinity of the ice edge). 5) Monitoring of the distribution, ...