Zooplankton monitoring using a twin NORPAC net during the 59th Japanese Antarctic Research Expedition in austral summer 2017-2018

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-59 (December 2017 to March 2018). 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 2017/2018 voyage. In additions, a transects by the T/V Umitaka-maru was also carried out along 110E longitude in January 2018. 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 40 years. These transect data can be used as time series and/or seasonal sets.作为日本南极研究考察队（Japanese Antarctic Research Expedition, JARE）监测计划的组成部分，自第14次考察（JARE-14，1972/1973年度）起，科研人员便常规采用NORPAC（北太平洋，NORth PACific）标准网开展浮游动物采样，以评估南大洋印度洋扇区表层150米水深范围内浮游动物的丰度、物种组成及其时空变化的长期趋势。第59次考察（JARE-59，2017年12月至2018年3月）期间共完成两项独立的监测调查。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°南下，次年3月沿东经150°返航，其航行轨迹极为适合该区域的长期监测工作。本研究呈现该船2017/2018年度航次的观测数据。此外，"海鹰丸"号调查船（T/V Umitaka-maru）于2018年1月沿东经110°开展了断面调查。因此，本报告提供了最新的浮游动物数据，该数据是JARE近40年来在该区域开展的浮游动物长期监测计划的组成部分。这些断面调查数据可作为时间序列数据集或季节数据集加以应用。