Zooplankton monitoring using a twin NORPAC net during the 61st Japanese Antarctic Research Expedition in austral summer 2019-2020

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-61 (December 2019 to March 2020). The icebreaker Shirase has a fixed schedule and route, traveling down longitude 110E each December and returning along 150E each March. Data collected on these fixed schedule seems to be ideal for long-term monitoring work in this region. We present data from its 2019/2020 voyage. In additions, separate samplings were carried out on board the T/V Umitaka-maru along 110E longitude in January 2020. This report provides the latest zooplankton data. These transect data can be used as time series and/or seasonal sets over the last 45 years.