Abstract
We present the elemental composition (Al, Cd, Co, Cu, Fe, Mn, Mo, Ni, V, Zn, and P) of field-collected Trichodesmiumpo pulations. To distinguisht he effects of river discharges( Amazon and Niger Rivers) and
Saharand ust deposition on metal concentrationsi n the colonies, samplesw ere collected both in the western (February 2001, July-August 2001, and April-May 2003) and eastern (May-June 2003) basins of the North Atlantic.M etalc omposition( mediansn ormalizedt o P) in Trichodesmiurma ngedf rom 0.011 mmol mol- for Co to 39 mmol mol-l for Fe and varied over an order of magnitude among different locations. A comparison of
metal ratios measuredi n the Trichodesmiumco loniesw ith ratios reportedf or the potentials ourcess uggestst hat the most importants ourceso f tracem etalst o the tropicala nd subtropicaAl tlanticd uringo ur samplingw eret he Amazon and Niger Rivers, rather than dust deposition from the Sahara. | 8 pages, 3 figures, 2 tables. | This work was supported by funds from the NOAA Carbon Sequestration Program (award NA040AR4310097) and NSF (OCE 9912333) to S.A.S.-W. and by Spanish "Plan Nacional de
I+D" CICYT (REN-2000-1471-C02)t o S.A. A fellowship from the Spanish Ramon y Cajal Programme supported A.T.-S.