Krill
Krill are small, shrimp-like crustaceans in the order Euphausiacea found in oceans around the world.
Krill are small, shrimp-like crustaceans in the order Euphausiacea found in oceans around the world. They are a major part of marine food webs, feeding on phytoplankton and serving as food for many fish, birds, seals, and whales.
Classification and anatomy
Krill are crustaceans in the order Euphausiacea, distinct from true shrimp. They are small, shrimp-like animals with multiple species described from ocean waters worldwide.
Distribution and habitat
Krill live in oceans across the globe, with many species concentrated in open-ocean and polar waters. Antarctic krill are especially important in the Southern Ocean, where they form dense biomass.
Feeding and ecological role
Krill feed mainly on phytoplankton and help transfer energy from microscopic algae to larger animals. This makes them a foundational link in marine food webs.
Human importance
Krill are harvested in some regions and are also studied for their role in climate and ocean ecosystems. Antarctic krill fisheries are especially significant in the Southern Ocean.
Key facts
- Krill are a group of shrimp-like crustaceans in the order Euphausiacea, not a single species.
- They feed mainly on phytoplankton and are a key prey species for many marine animals.
- Krill occur in large swarms and are abundant in nutrient-rich waters, especially in polar regions.
- Antarctic krill are a major food source in the Southern Ocean and are commercially fished.
- Krill play an important role in the ocean carbon cycle and marine food webs.
Krill are relevant to Canadian marine science, ocean food webs, and conservation discussions, especially through comparisons with North Pacific species and broader concerns about climate change, fisheries, and ocean ecosystems.
Frequently asked questions
What are krill?
Are krill a single species?
What do krill eat?
Why are krill important?
Where are Antarctic krill found?
Are krill commercially fished?
References
- National Geographic — https://www.nationalgeographic.com/animals/invertebrates/facts/krillSupports: General definition, diet, ecological role, species diversity, Antarctic krill size and longevity
- Australian Antarctic Program — https://www.antarctica.gov.au/about-antarctica/animals/krill/Supports: Antarctic krill species presence in Antarctic waters and dominance of Euphausia superba
- Pew Charitable Trusts — https://www.pew.org/en/research-and-analysis/articles/2022/08/11/8-facts-about-antarctic-krill-show-why-they-need-greater-protectionSupports: Krill classification as zooplankton and size comparison
- Woods Hole Oceanographic Institution — https://www.whoi.edu/ocean-learning-hub/ocean-facts/krill/Supports: Krill as filter feeders and role in the marine food chain
- Britannica Kids — https://kids.britannica.com/students/article/krill/602870Supports: Krill as crustaceans, order Euphausiacea, size range, swarming, and food source role
- National Science Foundation — https://www.nsf.gov/science-matters/antarctic-krill-superheroes-southern-oceanSupports: About 86 species, ecological importance, and Antarctic krill fishery
- Japan Ministry of the Environment — https://www.env.go.jp/nature/nankyoku/kankyohogo_en/key_word_en/okiami.htmlSupports: Antarctic krill size, lifespan, and importance as a principal food source