What is Krill?

Antarctic krill is abundant

Krill are tiny shrimp-like crustaceans (creatures with a hard external skeleton) that make up what many scientists believe to be among the largest biomasses on the planet, weighing almost double that of all the humans on Earth. Scientists estimate the total quantity to be between 500 and 800 million tons. Among multicelled organisms, only ants are thought to run a close second, biomass-wise.  

There are some 85 species of krill living in the world’s oceans, but the species that swims in the pure Antarctic waters, Euphausia superba, is the one currently being harvested for the nutritional properties contained in its oil and meat. In Japan, krill meat is known as okiami. The Japanese and Russians have been harvesting krill for many decades.

Antarctic krill is what is called a keystone species; that is, a species on which many of these oceans’ predators depend on for their food, including whales (who can consume up to seven tons a day), seals, squid, penguins and many species of birds.  (BBC has produced a short, dramatic video of humpback whales fishing for krill in the Antarctic.)

Krill normally spend their daylight hours in huge swarms at depths of up to 350 feet, where they are safe from many of their predators. These swarms are dense – they can extend to four miles and contain up to 100,000 krill per cubic meter. Scientists have observed swarms spreading over more than 450 square kilometers (279 square miles). Antarctic krill are bioluminescent – that is they emit a strong blue-green light that may be a means of communication to help them congregate.

As it grows dark, the krill rise to feed on algae called phytoplankton, single-celled plants that live on the underside of and within Antarctic ice. Phytoplankton contain astaxanthin, a powerful antioxidant in humans, which is what gives krill their distinctive red-orange color. Astaxanthin is also among the pigments that give creatures, such as salmon, lobsters, and flamingos their color (See Astaxanthin).

Because Antarctic krill are so important to so many other species, nations bordering the Antarctic Ocean, including Australia, South Africa, New Zealand with Argentina and Chile, formed a treaty organization (CCAMLR) to ensure that krill were being harvested sustainably. Formed in 1982, CCAMLR currently counts 25 nations as members, including the United States, Russia and Japan.

You can read about krill oil benefits for health here. 

Read about what is in krill oil here. 

We address sustainability issues of krill harvesting elsewhere on this site.

Read about liquid krill oil here.

Read about krill oil and fish oil testing results by Consumerlab.com. 

Krill oil vs fish oil: What's the difference?

Disclaimer: The information provided in this krill oil forum is a public service of WellWise.org, and should not in any way substitute for the advice of a qualified healthcare professional and is not intended to constitute personal medical advice.