Long term monitoring of particle fluxes in the Bering Sea and the central subarctic Pacific Ocean, 1990–2000

A time-series particle flux study has been conducted at two sites near the Aleutian Islands: Station AB in the Bering Sea for nine years (1990–1999) and Station SA in the central subarctic Pacific for ten years (1990–2000). Significant variability in seasonal and inter-annual particle flux was observed at both stations. The annual primary flux maxima that occurred during spring through summer tended to vary considerably in their timing and magnitude, whereas the secondary maxima in fall tended to be fairly consistent of timing and flux levels. Biogenic opal contributed to a major portion of the time-series fluxes. Especially diatoms such as Neodenticula seminae are important in the biogenic opal fluxes and drive bulk of the biological system. Calcium carbonate fluxes were comprised of six species of planktonic foraminifera and mainly two species of coccolithophores. At Station AB, the fall CaCO3 flux maxima were higher than those of spring, whereas the magnitudes of the CaCO3 flux maxima were similar during both spring and fall at Station SA. The seasonal change in CaCO3 flux was significantly different from that of biogenic opal. The planktonic foraminiferal contribution was greater than that of coccoliths to the total CaCO3 flux.