Deep-Sea Research I 47 (2000) 1723}1759 Long-term biogenic particle #uxes in the Bering Sea and the central subarctic Paci"c Ocean, 1990}1995 Kozo Takahashi*, Naoki Fujitani, Mitsuru Yanada, Yoshiaki Maita Department of Earth and Planetary Sciences, Graduate School of Sciences, Kyushu University 33, Hakozaki 6-10-1, Fukuoka, 812-8581, Japan Department of Marine and Fisheries Sciences, Faculty of Fisheries, Hokkaido University, Minato-cho 3-1-1, Hakodate, 041-8611, Japan Received 4 August 1999; received in revised form 7 December 1999; accepted 7 December 1999 Abstract Time-series sediment traps were deployed for "ve consecutive years in two distinctively di!erent subarctic marine environments. The centrally located subarctic pelagic Station SA (493N, 1743W; water depth 5406 m) was simultaneously studied along with the marginal sea Station AB (53.53N, 1773W; water depth 3788 m) in the Aleutian Basin of the Bering Sea. A mooring system was tethered to the sea-#oor with a PARFLUX type trap with 13 sample bottles, which was placed at 600 m above the sea-#oor at each of the two stations. Sampling intervals were synchronized at the stations, and they were generally set for 20 days during highly productive seasons, spring through fall, and 56 days during winter months of low productivity. Total mass #uxes, which consisted of mainly biogenic phases, were signi"cantly greater at the marginal sea Station AB than at the pelagic Station SA for the "rst four years and moderately greater for the last year of the observations. This re#ects the generally recognized higher productivity in the Bering Sea. Temporal excursion patterns of the mass #uxes at the two stations generally were in parallel, implying that temporal changes in their biological productiv- ity are strongly governed by a large-scale seasonal climatic variability over the region rather than local phenomena. The primary reason for the di!erence in total mass #ux at the two stations stems mainly from varying contributions of siliceous and calcareous planktonic assemblages. A signi"cantly higher opal contribution at Station AB than at Station SA was mainly due to diatoms. Diatom #uxes at the marginal sea station were about twice those observed at the pelagic station, resulting in a very high opal contribution at Station AB. In contrast to the opal #uxes, CaCO  #uxes at Station AB were slightly lower than at Station SA. * Corresponding author. Fax: 81-92-642-2686. E-mail address: kozo@geo.kyushu-u.ac.jp (K. Takahashi). 0967-0637/00/$ - see front matter  2000 Elsevier Science Ltd. All rights reserved. PII: S 0 9 6 7 - 0 6 3 7 ( 0 0 ) 0 0 0 0 2 - 9