Zooplankton monitoring using a twin NORPAC net during the 60th Japanese Antarctic Research Expedition in austral summer 2018-2019

As part of the monitoring program of the Japanese Antarctic Research Expedition (JARE), zooplankton sampling using a NORPAC (NORth PACific) standard net has been routinely carried out since JARE-14 (1972/73 season) to estimate the long-term trends of abundance, species composition and their temporal/spatial variation in the uppermost 150 m of the Indian Ocean sector of the Southern Ocean. Two separate monitoring surveys were completed during JARE-60 (December 2018 to March 2019). The icebreaker Shirase has a fixed schedule and route, travel down longitude 110E each December and return along 150E each March, making its voyages ideal for long-term monitoring work in this region. We present data from its 2018/2019 voyage. In additions, a transects by the T/V Umitaka-maru was also carried out along 110E longitude in January 2019. Thus, this report provides the latest zooplankton data, forming part of the long-term monitoring of zooplankton carried out by JARE in this region for the last 45 years. These transect data can be used as time series and/or seasonal sets.

作为日本南极科考队（Japanese Antarctic Research Expedition, JARE）监测计划的组成部分，自第14次南极科考（JARE-14，1972/1973年度）起，研究团队便常规采用NORPAC（北太平洋标准网，NORth PACific）标准网开展浮游动物采样工作，以估算南大洋印度洋扇区表层150米水域内浮游动物的丰度、物种组成及其时空变化的长期趋势。第60次南极科考（JARE-60，2018年12月至2019年3月）期间共完成两次独立的监测航次。破冰船“白濑号（Shirase）”设有固定的航行计划与航线：每年12月沿东经110°向南航行，次年3月沿东经150°返航，其航行路径非常适配该区域的长期监测工作。本报告呈现了该船2018/2019年度航次的采样数据。此外，“海鹰丸号（T/V Umitaka-maru）”也于2019年1月沿东经110°完成了一条断面采样航线。综上，本报告提供了最新的浮游动物采样数据，是日本南极科考队近45年来在该区域开展的长期浮游动物监测工作的组成部分。这些断面采样数据可作为时间序列数据集或季节数据集加以利用。