©2008 WGBh Educational Foundation. All Rights Reserved.

©2007 WGBH Educational Foundation. All rights reserved. Concept adapted from Bigelow Laboratory for Ocean Sciences. Materials courtesy of British Antarctic Survey (Krill Image), Doug Allan/British Antarctic Survey (Icefish Image), Kristan Hutchison—Antarctic Sun Staff (Snow petral), NOAA (Blue whale), and Robert Pittman (Killer whales).