what is a krill

Krill are small, shrimp-like crustaceans found in all the world's oceans. They are an important element of the aquatic food chain, converting the primary production of their prey into a form suitable for consumption by larger animals that cannot feed directly on minuscule algae. Krill are an essential food source for many marine animals, including fish, penguins, seals, and baleen whales. They are rich in protein and omega-3 fatty acids and are used in human food, dietary supplements, livestock food, and pet food. Krill feed on phytoplankton and are themselves the main staple in the diets of hundreds of different animals. Antarctic krill, one of the most abundant and successful animal species on the planet, is among the largest of the 85 known krill species and is an essential part of the Antarctic ecosystem. However, there are concerns about declining krill populations, with studies showing that Antarctic krill stocks may have dropped by 80 percent since the 1970s, partly due to ice cover loss caused by global warming