How iron gets into the North Pacific

Says Lam, "It takes only a simple calculation to show that iron delivered from the continental shelf, under the surface, is at least as important here as iron from airborne dust. And we suspect this is the case for the iron supply in other, similar regions of the oceans."

Lam and Bishop's findings have implications far beyond correcting estimates of the iron budget in HNLCs.

"Just looking at a map and considering the history of geochemical processes like volcanism and their influence on the biology of the oceans -- and what's already happening as the climate gets warmer, the glaciers melt, and the edges of the continents are altered drastically -- it's clear how little we understand how these changes are likely to affect the productivity of the ocean and its ability to store atmospheric carbon," Bishop says. "Before we start playing around with massive-scale, commercial iron fertilization, we have a lot of science yet to do. Natural iron, and associated elements, seem to cause a significantly different biological response than has been seen in the dozen fertilization experiment to date. It would be good to know why."

"The Continental Margin is a Key Source of Iron to the HNLC North Pacific Ocean," by Phoebe J. Lam and James K. B. Bishop, will appear in a forthcoming edition of Geophysical Research Letters and is now available to subscribers at http://www.agu.org/contents/journals/ViewPapersInPress.do?journalCode=GL#id2008GL033294. Once published, the paper will be available from the Geophysical Research Letters website at http://www.agu.org/journals/gl/.

This research was funded by the U.S. Department of Energy's Office of Science, Biological and Environmental Research Program, and by the Woods Hole Oceanographic Institution, the Richard B. Sellars Endowed Research Fund, and the Andrew W. Mellon Foundation. Portions of the work were carried out at DOE's Advanced Light Source at Berkeley Lab and DOE's Stanford Synchrotron Radiation Laboratory.

Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified scientific research and is managed by the University of California. Visit our website at http://www.lbl.gov.