Zooplankton monitoring using a twin NORPAC net during the 63rd Japanese Antarctic Research Expedition in austral summer 2021-2022

As a part of the monitoring programs 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. The icebreaker Shirase has a fixed schedule and route, traveling down longitude 110 degree E each December. Data collected on fixed schedule seems to be ideal for long-term monitoring work, and can be used as time series and/or seasonal analysis. Due to the influence of COVID-19, monitoring program of JARE-62 (2020-2021) was canceled, and JARE-63 (2021-2022) was reduced the sampling plan. Sampling was conducted during the daytime at two stations during JARE-63 (December 2021).作为日本南极考察队（Japanese Antarctic Research Expedition, JARE）监测计划的组成部分，自第14次考察（1972/1973年度）起，科研人员便常规采用北太平洋标准网（NORPAC, NORth PACific）开展浮游动物（zooplankton）采样工作，以估算南大洋印度洋扇区上层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。考察船“白濑号（Shirase）”设有固定的航行计划与航线，每年12月沿东经110°航线航行。基于固定日程采集的数据非常适合用于长期监测工作，可应用于时间序列分析及/或季节变化分析。受COVID-19疫情影响，第62次日本南极考察（2020-2021年度）的监测计划被迫取消，第63次考察（2021-2022年度）的采样方案也有所缩减。在第63次考察期间（2021年12月），科研人员于日间在两个采样站位开展了采样工作。