The Diet of Krill

Krill are small, shrimp-like marine animals that dwell in the Southern Ocean, the waters between Antarctica and the Atlantic, Pacific and Indian Oceans. Krill are primarily herbivorous and are dietary staples of whales, seals, aquatic birds and other marine life.

  1. Diet

    • Krill feed on phytoplankton, unicellular plants that subsist on sunlight and carbon dioxide, and on ice algae, which grows in colonies on the underside of Antarctic ice packs. Krill can also feed on their own eggs, larva, excrement and on other krill.

    Carbon Removal

    • Several times a night, krill swim deep into the ocean to excrete waste that includes the carbon they've ingested from phytoplankton. The British Antarctic Survey reports that the krill population, which has a greater combined mass than humanity, acts in concert with phytoplankton to remove the greenhouse gas CO2 from the atmosphere and transport it safely to the ocean floor.

    Population Decline

    • National Geographic reports that the krill population may have declined 80 percent since the 1970s. Commercial fishing and the melting of the Antarctic ice shelf that's home to the red algae they prey on are the major threats to the krill's survival.