Limnol. Oceanogr., 44(2), 1999, 447–454

Geophysical and ecological dynamics within lakes of the McMurdo Dry Valleys, Antarctica, are controlled by the presence of permanent ice covers. Despite the importance of the permanent ice cover, there have been no studies that have examined specific couplings between changes in the geophysical properties of the ice covers and dynamic ecological processes within the underlying water column. Herein we present seasonal irradiance and primary production data from Lake Bonney, Taylor Valley, and we show that the phenomena of ‘‘ice whitening’’ is caused by changes in the scattering properties within the upper meter of the ice column and that the timing and extent of this phenomena exerts a predominant constraint on primary production and overall phytoplankton