Material scraped off land by glaciers and carried to sea by icebergs nourishes life in frigid Antarctic waters.
Late in 2005, oceanographers conducted separate biological surveys near two large icebergs in the South Atlantic. One, an ice mass about 2 kilometers long and 0.5 km wide, drifted more than 120 km in 8 days, says Kenneth L. Smith Jr., an oceanographer at the Monterey Bay Aquarium Research Institute in Moss Landing, Calif. Currents carried the other iceberg—30.8 square kilometers in area—about 531 km during an 18-day period.
Smith and his colleagues assayed the ocean around each iceberg from about 20 meters to 9 km away. Phytoplankton, the organisms at the base of the ocean's food chain, were about five times as abund