Terrestrial biodiversity is low. Antarctic seas are extremely productive
because phytoplankton grow abundantly during the extended daylight of summer
and feed large populations of krill. Krill, which are shrimp-like crustaceans, are a
key animal in this ecosystem. They serve as food for top predators, such as
whales, penguins, and seals.
Figure 4.6 Antarctic food webMajor Environmental Threats
■ Climate change and global warming, resulting in a warming of the sea and
the loss of sea and land-based ice.