What Are Krill?

Most people have heard of krill, but unless they are fishermen, connoisseurs of Japanese cuisine or marine biologists, they are not likely to know much about them aside from the fact that they are reminiscent of other small crustaceans, such as shrimp. Krill are actually a very important part of the ocean's ecosystem, however. This is why these small animals, which are very near the bottom of the food chain, are so popular and critically studied by scientists and animal preservationists.

Identification

Krill are tiny invertebrate animals that are no more than 2 inches long. They look and taste similar to shrimp, although they tend to have a "fishier" taste. According to Cool Antarctica, krill can live up to six years, which is amazing considering what a significant source of food they are for their fellow ocean dwellers. In fact, the term krill actually means "whale food" in Norwegian.

Where They are Found

Krill can be found in all four of the world's oceans. They are typically found in deeper parts of these oceans during the daytime, but they consistently migrate, and eventually end up near the oceans' surface once it gets dark.

Behavior

Aside from being keen on constant migration, krill tend to swim in parks, or swarms, as they are often called. This term is fitting because krill are extremely small. Therefore, if one were to encounter a "pack" of krill it would look more like a swarm of small insects than a group of animals. They spend their days at the bottom of the ocean because it is a place where they are allowed to relax more. There are significantly fewer predators down there, and the colder temperatures allow them to conserve their energy before migrating to the surface where they will have to fend off predators as they attempt to feed.

Purposes

According to National Geographic, krill are "essentially the fuel that runs the engine of the Earth's marine ecosystems." What they mean by this is that hundreds of mammals, birds and fish feed on them. Krill are staples to these animals' diets because the shrimp-like creatures eat phytoplankton and zooplankton, which can then be absorbed by the larger animals for their nutrients, such as phosphate and nitrate. They are also used as bait for fishing and even as food in the Japanese culture.

Shortages

Though you wouldn't know it if you encountered a swarm of krill, the animals are actually not as abundant as they used to be. This can be extremely dangerous to the ocean's delicate eco system because so many animals depend on krill as a source of vitamins and nutrients. In fact, a British Antarctic Survey found that the krill population in Antarctica has decreased by more than 80 percent since the 1970s.