The mean and range of duplicate values of cell-specific bacterial production rates are shown for day 7 for all treatments. Bacterial communities were incubated with water from ice melt containing ice algae (ice algae), from the chlorophyll maximum (chl max), or from aphotic zone water (aphotic) for one week. An aphotic zone bacterial control (control) containing no new DOM was also included. Bacteria for ice algae, chl max and control treatments were collected from the aphotic zone (170 m); bacteria for the aphotic treatment were collected from the chlorophyll maximum (10 m). All water was from the Amundsen Sea Polynya, Antarctica (Figure 1).