Japanese Arctic projects’ contributions to the Central Arctic Ocean Fisheries Agreement

Since the previous Japanese Arctic projects (ArCS and ArCS II projects), we have accumulated and evaluated scientific data, providing knowledge to the Joint Program for Scientific Research and Monitoring (JPSRM) established under the Central Arctic Ocean Fisheries Agreement (CAOFA). This knowledge could form the basis for conserving and utilizing marine resources. Here, contributions of the Japanese Arctic studies to the CAOFA JPSRM Implementation Plan are presented. During the 2020 R/V Mirai cruise in collaboration with the Synoptic Arctic Survey (SAS), unusually low oxygen and acidified water was found on the Chukchi Borderland (CBL), a high-seas fishable area of the Pacific Arctic. The integrated SAS data suggested that Beaufort Gyre shrinkage and Atlantification triggered a frontal northward flow along the CBL that transported the low oxygen and acidified water from the shelf-slope north of the East Siberian Sea. Therefore, the CBL area should be monitored as a bellwether of ecosystem degradation caused by ocean acidification and deoxygenation in the Central Arctic Ocean. This finding was cited in the CAOFA JPSRM Implementation Plan, and is proposing a most urgent monitoring site, which is at risk of ocean acidification and deoxygenation, in the Agreement Area. Future contributions to the CAOFA JPSRM are expected through the scientific surveys that will be conducted by the Japanese new icebreaker, Arctic Research Vessel (ARV) Mirai II.