Krill

Krill are small crustaceans of the order Euphausiacea, and are found in all the world's oceans. The name krill comes from the Norwegian word krill, meaning "small fry of fish”, which is also often attributed to species of fish.

Antarctic_krill_(Euphausia_superba)

Antarctic krill Euphausia superba. image: wikimedia/Uwe Kils

Krill are considered an important trophic (food energy) level connection – near the bottom of the food chain – because they feed on phytoplankton and (to a lesser extent) zooplankton, converting these into a form suitable for many larger animals for whom krill makes up the largest part of their diet. 

How many are there? what is their biomass?

In the Southern Ocean, one species, the Antarctic krill, Euphausia superba, makes up an estimated biomass of around 379,000,000 tonnes, making it among the species with the largest total biomass. 

Krill_swarm

A swarm of krill. image: Jamie Hall - NOAA/wikipedia

Of this, over half is eaten by whales, seals, penguins, squid and fish each year, and is replaced by growth and reproduction. Most krill species display large daily vertical migrations, thus providing food for predators near the surface at night and in deeper waters during the day.

Commercial fishing

Krill are fished commercially in the Southern Ocean and in the waters around Japan. The total global harvest amounts to 150,000–200,000 tonnes annually, most of this from the Scotia Sea. 

Most of the krill catch is used for aquaculture and aquarium feeds, as bait in sport fishing, or in the pharmaceutical industry.

 In Japan, Philippines and Russia, krill are also used for human consumption and are known as okiami (オキアミ?) in Japan. 

They are eaten as "camarones" in Spain. In the Philippines, it is known as "alamang" and it is used to make a salty paste called bagoong.

Krill are the main prey of baleen whales, including the blue whale.


source adapted from: Krill. (2017, April 21). In Wikipedia, The Free Encyclopedia. Retrieved 09:32, April 27, 2017, from https://en.wikipedia.org/w/index.php?title=Krill&oldid=776434032