(noun) Small, shrimp-like crustaceans in the scientific order Euphauslacea that are a vital food source for many pelagic birds, including penguins, albatrosses, shearwaters, petrels and other seabirds. Krill are found in all the oceans on Earth, and are believed to be the most abundant organism on the planet in terms of biomass. A single krill is roughly 2 inches long and has a pale pink, opaque coloration.
Krill feed on phytoplankton and can form massive schools or swarms that will attract many other animals to feed. These crustaceans have vertical migrations on a daily basis depending on the nutrient content and temperature of the water, and animals can feed on krill at different levels.
A healthy krill population is essential for many birds and other creatures that prey on the crusteaceans, including fish and whales. Water temperature and salinity changes, as well as other aspects of climate change, can affect krill populations. Oceanic pollution is also a threat to krill. If krill populations are affected, birds can suffer from the necessity of flying or swimming further from breeding grounds in order to feed adequately, resulting in higher mortality for both adults and hatchlings.
Photo – Penguins and Cormorants © Liam Quinn