Aquatic Sciences Meeting, Albuquerque 2001

CS10 Continental Shelf Processes: Benthos and Pelagos

Date: Thursday, February 15, 2001, Time: 2:30:00 PM

Location: Aztec

McRoy, C, , University of Alaska Fairbanks, Fairbanks, USA, ffcpm@uaf.edu

Whitledge, T, E, University of Alaska Fairbanks, Fairbanks, USA, whitledge@ims.uaf.edu

Springer, A, M, University of Alaska Fairbanks, Fairbanks, USA, ams@ims.uaf.edu

Simpson, E, P, University of Alaska Fairbanks, Fairbanks, USA, psimpson@murre.ims.uaf.edu

THE NITRATE FRONT IN THE BERING SEA: IS THIS AN IRON CURTAIN?

The phytoplankton bloom in the Bering Sea is concomitant with a strong gradient of nitrate in the surface along the shelf border from high (>10 µM) in basin waters to low (<1µM) over the shelf. This gradient has been documented by Japanese and US-Russia expeditions. Transition from basin to shelf and the nitrate front is associated with high production and biological diversity throughout spring and summer. This region, the "Green Belt," is recognized as a unique habitat with congregations of fish, seabirds and mammals. The Green Belt runs through the ocean just seaward of the shelf break but processes sustaining the Green Belt remain the subject of speculation. Examination of data lead to the conclusion that the Green Belt forms due to the combination of nutrients essential for phytoplankton growth. The shelf supplies iron to the nitrate-rich ocean waters of the basin. This is an IRON CURTAIN as indicated by the nitrate front. No iron data exist for this contention. We present evidence for the interactions of nitrogen-rich/iron-poor basin waters with nitrogen-poor/iron-rich shelf waters.

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Aquatic Sciences Meeting, Albuquerque 2001

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