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

• Format: Article in Journal/Newspaper
• Language: English
• Published: National Institute of Polar Research 2021
• Subjects: Zooplankton monitoring; NORPAC net; Southern Ocean; Antarctic; Austral; Indian; Pacific; Antarc*
• Online Access: http://id.nii.ac.jp/1434/00000028/; https://pdr.repo.nii.ac.jp/?action=repository_uri&item_id=42; https://pdr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=42&item_no=1&attribute_id=22&file_no=1; https://pdr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=42&item_no=1&attribute_id=22&file_no=2; https://pdr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=42&item_no=1&attribute_id=22&file_no=3

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. 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 110ºE each December and returning along 150ºE 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 110ºE 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.