The Institute of Cetacean Research
2025/2026 Japanese Abundance and Stock-structure Surveys in the Antarctic (JASS-A)
- Departure of Research Vessel
December 1, 2025
Designated Corporation for Scientific Whale Research
THE INSTITUTE OF CETACEAN RESEARCH
1. Background
This survey is the continuation of the Japanese government's research program (non-lethal research) aimed at sustainable use of whale resources in the Antarctic Ocean, and the seventh research cruise in the Antarctic after Japan's withdrawal from the International Whaling Commission (IWC) on June 30, 2019. The scientific validity and the value of this research have been confirmed by the IWC Scientific Committee.
The scientific information obtained from the research is provided to the IWC Scientific Committee, the Ecosystem Monitoring and Management Working Group of the Commission for the Conservation of Atlantic Marine Living Resources (CCAMLR) and the Scientific Committee of the North Atlantic Marine Mammal Commission (NAMMCO) and thus contributes to the appropriate management of whale resources in the Antarctic Ocean. In this year's research, we will continue to conduct sighting surveys, mounting satellite tags and collecting biopsy samples of cetaceans in the Antarctic Ocean.
The two research vessels Yushin Maru No. 3 and Yushin Maru No. 2 are departing from the Shiogama Port (Miyagi Prefecture) on 3 December 2025 and scheduled to return to Shiogama Port on 12 March 2026 after conducting non-lethal research in the Antarctic Ocean.
2. Outline of the 2025/2026 Research Cruise
This survey is financially supported by the Fisheries Agency of Japan, and the Institute takes the lead in planning, implementing and conducting analyses of data to be obtained from the survey.
2.1 Main research objectives
(1) Study of abundance and their trends of large whale species in the Antarctic Ocean.
(2) Study of the distribution, movement and stock structure of large whale species in the Antarctic Ocean.
2.2 Research Cruise Period
From 3 December 2025 to 12 March 2026 (100 days).
2.3 Research Area
Antarctic Ocean.
2.4 Researchers
Yushin Maru No. 3
Four researchers* led by Tatsuya Isoda (Cruise Leader, Deputy Director, Research Department I, The Institute of Cetacean Research).
*One researcher from Chile on board.
Yushin Maru No. 2
Three researchers led by Minato Kawasaki (Researcher, Research Center, The Institute of Cetacean Research).
2.5 Research Vessel
Yushin Maru No. 3, (742 tons, Captain Shigeru Nojima, 16 crews in total).
Yushin Maru No. 2, (747 tons, Captain Chikamasa Okoshi, 16 crews in total).
Thirty-nine members led by the Cruise Leader Isoda, Captain Abe, and Captain Okoshi will be on board to engage in the research.
2.6 Implementing body
Designated Corporation for Scientific Whale Research - The Institute of Cetacean Research.
2025/2026 Japanese Abundance and Stock-structure Surveys in the Antarctic (JASS-A) - Departure of Research Vessel (PDF file)