Physical, Biogeochemical, and Ecosystem Studies for Sub-Arctic Sea taken by CTD and other instruments from the R/V Mirai in the North Pacific from 2017-07-10 to 2017-08-21 (NCEI Accession 0304368)

A highly productive habitat named as “Green Belt” locates along the edge of the continental shelf in the Bering Sea. Enormous seabirds and whales accumulate in a limited area of the south-eastern Bering Sea during summer, which is called as “the Aleutian Magic”. To elucidate the mechanism of this biological phenomenon, we conducted oceanographic researches using R/V Mirai during the period of the Aleutian Magic. This cruise started on August 5, 2017 at Dutch Harbor, Alaska, USA and ended on August 21, 2017 at Dutch Harbor. We conducted bottom observations and biological sampling using a deep-tow camera system equipped with a dredger (11 tows), multi-layer plankton sampling using the Vertical Multiple Plankton Sampler (VMPS, 32 casts), sediment core sampling using a multiple corer (13 casts), water sampling and physico-chemical measurements using a CTD and Niskin bottle carousel (46 casts in total) at depths between 0 – 2500 m. Sediments in areas shallower than 1000 m were coarse and no evidence was seen for xtraordinary organic falls. In contrast, sediments in areas deeper than 1500 m were fine, which were similar to “ordinary” deep-sea sediments. About 10 times of the Aleutian Magic were observed during this cruise at a depth of 100 m at the east end of the Bering Canyon. These events occurred in a small region (named as “Station M”), which was similar to that of previous records. CTD/hydro casts and plankton sampling were conducted across Station M. Higher concentrations of turbidity and chlorophyll were observed at downstream location from the station. Many Limacina and Clione gastropods were collected and a dense aggregation of juvenile cods were observed at Station M.
Cruise data are available from the JAMSTEC DARWIN portal, see the Documentation on the dataset landing page.
This dataset is U.S. State Department MSR U2016-038 as part of the World Data Services for Geophysics and Oceanography.