A Delicate Balance

Ringed seals, like the one pictured here, are the smallest and most common seals found in the Arctic. Their diets consist mainly of shrimp, krill and other small crustaceans and they are the main food for polar bears. Learn more about the Arctic ecosystem on Polar Discovery, a project to document science in action from pole to pole during the 2007-2009 International Polar Year. This image was taken on the 2009 Bering Sea Ecosystem Expedition, which focused on sea ice and how climate change will affect the region’s delicately balanced ecosystem. (Photo by Chris Linder, Woods Hole Oceanographic Institution)