Successful Australia-Japan collaboration and student mentoring

第6回極域科学シンポジウム[OB] 極域生物圏11月16日（月）　統計数理研究所 セミナー室1（D305

A new tool for monitoring the Antarctic marine ecosystem using environmental DNA

The Tenth Symposium on Polar Science/Ordinary sessions : [OB] Polar Biology, Wed. 4 Dec. / Entrance Hall (1st floor) , National Institute of Polar Researc

Zooplankton community structure influences the distribution of flying seabirds off Vincennes Bay, East Antarctica

The Tenth Symposium on Polar Science/Ordinary sessions : [OB] Polar Biology, Wed. 4 Dec. / Entrance Hall (1st floor) , National Institute of Polar Researc

Sexual dimorphism in body shape of Antarctic krill (Euphausia superba) and its influence on target strength

AbstractSexual dimorphism in the body shape of Antarctic krill (Euphausia superba) was investigated and its influence on target strength (TS) was clarified using a theoretical scattering model. The TS which is used to convert acoustic backscatter to krill density was also presented. Body shape data were obtained from 456 specimens (54 juveniles, 200 males, and 202 females) collected off Adélie Land using a Rectangular Midwater Trawl. The sexual dimorphism manifested as a swollen cephalothorax in female krill with body lengths exceeding 40 mm. The TS of female krill was higher than those of male krill at low frequencies, even when body lengths were the same. This is because of the Rayleigh scattering region and the transition region to the geometric scattering region. The influence of the sexual dimorphism on the TS was small at frequencies exceeding 70 kHz, which are close to the geometric scattering region. The regression curve derived from the predicted TS of 456 specimens was in reasonable agreement with the measured TS in other previous studies, and the regression curve could be applied to the acoustic surveys of Antarctic krill

Composition analysis of sinking particles by using gel sediment traps in the Indian sector of the Southern Ocean during austral summer

The Tenth Symposium on Polar Science/Ordinary sessions : [OB] Polar Biology, Wed. 4 Dec. / Entrance Hall (1st floor) , National Institute of Polar Researc

第53次日本南極地域観測隊 東京海洋大学研究練習船「海鷹丸」（KARE-15; UM-11-07）活動報告

2011/2012年夏シーズンに，東京海洋大学研究練習船「海鷹丸」の海洋研究航海が，南大洋インド洋区で行われた．この航海では東京海洋大学の共同研究5課題が行われた．このうち，以下の2課題が南極地域観測第Ⅷ期計画（第52?57次隊）関連研究であった．すなわち，一つは重点研究観測「南極から探る地球温暖化」のサブテーマの一つである「南極海生態系の応答を通して探る地球環境変動」で，もう一つは一般研究観測の「プランクトン群集組成の変動と環境変動との関係に関する研究」であった．これら南極観測事業関連研究のほか，東京海洋大学・国立極地研究所との共同研究である「南大洋の環境変動と生態系変動」，独立行政法人海洋研究開発機構（JAMSTEC）との共同研究「時系列観測による南大洋の大気・海洋環境変動の研究（南大洋ブイの開発）」，北海道大学との共同研究「南極底層水の動態に関する研究」も同時に実施された．「海鷹丸」は平成23年12月27日，フリーマントルを出港後，東経110度及び140度の海氷縁に及ぶ海域の観測を行い，平成24年2月1日，ホバート港へ寄港した．この間，プランクトン群集の分布を調べるため各種ネットによる曳網が行われたほか，物理観測，化学成分観測が行われた．また，昨シーズンに設置した長期係留系を回収した．また，「しらせ」から放流された漂流ブイ2系統を回収した．さらに，JAMSTECのm-TRITON ブイを設置した．こうした観測のほか，翼足類を用いた酸性化実験が船上で行われた．The training vessel Umitaka-maru of the Tokyo University of Marine Science and Technology (TUMSAT) undertook a marine science cruise in the Indian sector of the Southern Ocean during the 2011/2012 austral summer. During the cruise, TUMSAT conducted five different collaborative research projects. These included two phase-VIII Japanese Antarctic Research Expedition (JARE-52 to -57) projects: "Responses of Antarctic Marine Ecosystems to Global Environmental Changes with Carbonate Systems", which is the sub-theme of the prioritized research project "Exploring Global Warming from Antarctica"; and the ordinary research project "Studies on Plankton Community Structure and Environment Parameters in the Southern Ocean". The other three collaborative research projects were those undertaken in conjunction with (1) the National Institute of Polar Research, entitled "Environment and Ecosystem Changes in the Southern Ocean"; (2) the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), entitled "Deployment of the Southern Ocean Buoy" ; and (3) with Hokkaido University, entitled ＂Studies on Dynamics of Antarctic Bottom Water＂. The Umitaka-maru departed from Fremantle, Australia, on 27 December 2011, sailed to the study area around the marginal sea ice zone (mainly along 110°E and 140°E), and returned to Hobart, Australia, on 1 February 2012. The participants performed various net castings to qualitatively evaluate the vertical distribution of plankton communities, made physical observations, and measured chemical parameters. They also retrieved a year-round mooring that had been deployed the previous year, retrieved two surface drifting buoys that had been released by the ice breaker Shirase, and deployed a JAMSTEC buoy (m-TRITON). In addition, several acidified culture experiments using pteropods were conducted on board

Spatial distribution of pelagic fish off Adélie and George V Land, East Antarctica in the austral summer 2008

AbstractPelagic fish assemblages and community structure were examined along longitudinal and meridian transects off Adélie and George V Land, East Antarctica, in the austral summer 2008. Fish were sampled with an RMT 8 net principally from six discrete depth layers (0–50–100–200–500–1000–2000 m) in the oceanic zone and from three depth layers (0–50–100–200 m) over the continental shelf zone. A total of 20,281 individuals from 27 species were collected. Pleuragramma antarcticum was the most dominant species by number (18,710 inds), followed by Chionodraco hamatus (768), Trematomus newnesi (375), Cyclothone microdon (101), Electrona antarctica (92), Bathylagus antarcticus (51) and Notolepis coatsi (54). Cluster analysis revealed that the fish community was clearly divided at the Antarctic Slope Front into separate oceanic and shelf assemblages, being dominated by mesopelagic fish and notothenioids, respectively. The Southern Boundary of Antarctic Circumpolar Current likely restricted a more northern distribution of notothenioids in the upper 200 m. Mesopelagic fish dominated the large biomass below 500 m and notothenioids dominated that in the upper 100 m. It is considered that mesopelagic fish in the oceanic zone would unlikely be eaten by seabirds because no distinctive diel vertical migration to the surface layer was observed. In the neritic zone, notothenioids (C. hamatus, T. newnesi and P. antarcticum) possibly play an important role as prey items for flying seabirds, penguins and other notothenioids fish especially in the shallow depth stratum (0–100 m)

南大洋生態系に関する統合的研究 ～海氷下のブラックボックスを開けるために～

第6回極域科学シンポジウム分野横断セッション：[IG] 全球環境変動を駆動する南大洋・南極氷床11月17日（火）　国立極地研究所 2階 大会議

Meridional changes of zooplankton community and copepods population along 110°E transect in the Indian sector of the Southern Ocean during austral summer

The Tenth Symposium on Polar Science/Ordinary sessions : [OB] Polar Biology, Wed. 4 Dec. / Entrance Hall (1st floor) , National Institute of Polar Researc

Eukaryotic community structure in sinking particles in the seasonal sea ice zone of the Southern Ocean

The Tenth Symposium on Polar Science/Ordinary sessions : [OB] Polar Biology, Wed. 4 Dec. / Entrance Hall (1st floor) , National Institute of Polar Researc