What are krill's habitat and environment?

Krill primarily inhabit the cold, nutrient-rich waters of the world's oceans, particularly in the Southern Ocean surrounding Antarctica. They thrive in areas with abundant phytoplankton, which serve as their primary food source. These small crustaceans are often found in large swarms at various depths, depending on environmental conditions such as temperature and light availability. Krill play a crucial role in the marine ecosystem, serving as a key food source for various marine animals, including whales, seals, and seabirds.