Sea ice-derived dissolved iron and its potential influence on the spring algal bloom in the Bering Sea

Abstract

Observational and modeling studies in the Bering Sea indicate that changes in the seasonal ice cover and time of ice retreat influence open-water productivity. In particular, the timing of the spring bloom and its phytoplankton community composition are affected. Dissolved iron (DFe) data in the water column and ice cores collected during the 2007- Bering Ecosystem Study (BEST) cruise indicate that the melting ice provided substantial DFe to the water column. The additional DFe input from melting sea- ice could be biologically important along the outer shelf and shelf break where in ice-free areas insufficient DFe (<1 nM) existed for the complete assimilation of available nitrate (>20 μM). Variability in sea ice dynamics are likely to result in a varying supply of DFe to the outer shelf and shelf break in early spring, and to contribute to the observed changes in the timing and community composition of the spring phytoplankton bloom. Copyright 2008 by the American Geophysical Union.