Antarctic krill are one of the world’s most abundant multi-celled animals. Scientists estimate the biomass of Antarctic krill to be around 380 million tonnes – greater than the weight of all humans on Earth .
They are the key species of most food webs in the Southern Ocean.
Harvested krill is mainly used for the production of krill meal and krill oil, which in turn is used for animal feed and for direct human consumption through health products.
How they behave
Female krill lay up to 10 000 eggs at one time.As krill grow to maturity they gather into swarms (the collective name), sometimes stretching for kilometres in every direction, with many thousands of krill packed into each cubic metre of water, turning the water orange.
These swarms form columns that rise and fall, staying deep in the water during the day and rising to the surface at night. Why swarms are sometimes seen on the surface during daylight hours is unknown.
What they eat
Antarctic krill eat microscopic phytoplankton, single celled plants that drift up near the ocean’s surface. In their larval or juvenile stages of life krill feed on the green algae that grows on the underside of pack ice. Krill are the staple diet of hundreds of different animals, from fish to birds to seals and whales
Why are krill ecologically important?
Krill plays a key role in the Antarctic ecosystem and are a critical food source for many Southern Ocean species such as whales
, seals, fish, penguins
and other seabirds
. Hence it is important to avoid food competition from the fishery with predators, especially in the vicinity of breeding colonies. There are many current and emerging threats to their conservation and management, including climate change, and future increases in catch limits. Antarctic krill are very sensitive to climate change, including increased temperatures, the loss of sea ice and ocean acidification driven by rising carbon dioxide concentrations in seawater.
Who manages the krill fishery?
Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) is the international body responsible primarily for conserving Antarctic marine life. This includes managing fisheries activities in the Southern Ocean. It is committed to precautionary, ecosystem-based management, meaning that it is responsible for managing the impacts of fisheries on the health, resilience and productivity of the whole ecosystem.
Why is it important to source krill sustainably?
Although the overall population of Antarctic krill is large, fishing takes place in the same areas where many predators live and forage – around the Antarctic Peninsula. It is critical that krill harvesting be done in the most responsible and sustainable way possible to minimise impacts on Southern Ocean ecosystems.
Antarctic krill are very sensitive to climate change. It is critical that the fishery continues to be managed based on sound scientific evidence including understanding the impacts of climate change on current and future krill population sizes.
WWF supports Marine Stewardship Council (MSC) certification as the most robust and credible certification program for wild-capture fisheries. No other certification program provides as high a level of independent, transparent scrutiny on the sustainability of wild-capture fisheries. MSC’s standard recognises the importance of krill to the marine ecosystem.