Figure 1.

Map of sampling sites across the Amundsen Sea polynya that were visited during the Oden Southern Ocean (OSO) cruise in 2007–2008 (red dot) and the ASPIRE cruise in 2010–2011 (blue dots). Samples were grouped into three major regions: the Continental Shelf Break, the open waters of the polynya and waters abutting the Dotson Glacier. Insert: A map of chlorophyll a concentrations (red: high; purple: low) in polynyas abutting the Antarctic continent as estimated by remote sensing (courtesy of Dr. Kevin R. Arrigo, Stanford University). Note that sample numbers are only informative of the station number tracked during the ASPIRE cruise. The corresponding samples are presented in the supplemental material.