Wakame (Undaria pinnatifida) is a species of kelp native to cold, temperate coasts of the northwest Pacific Ocean.

[9] Wakame, as with all other kelps and brown algae, is plant-like in appearance, but is unrelated to true plants, being, instead, a photosynthetic, multicellular stramenopile protist of the SAR supergroup.

[17] Starting in the 1960s, the word wakame started to be used widely in the United States, and the product (imported in dried form from Japan) became widely available at natural food stores and Asian-American grocery stores, due to the influence of the macrobiotic movement, and in the 1970s with the growing number of Japanese restaurants and sushi bars.

[19] Wild-grown wakame is harvested in Tasmania, Australia, and then sold in restaurants in Sydney[20] and also sustainably hand-harvested from the waters of Foveaux Strait in Southland, New Zealand and freeze-dried for retail and use in a range of products.

[22] A study conducted at Hokkaido University found that a compound in wakame known as fucoxanthin may help burn fatty tissue in mice and rats.

[23] Studies in mice have shown that fucoxanthin induces expression of the fat-burning protein UCP1 that accumulates in fat tissue around the internal organs.

In Oriental medicine it has been used for blood purification, intestinal strength, skin, hair, reproductive organs and menstrual regularity.

[25] In Korea, miyeok-guk soup is popularly consumed by women after giving birth as sea mustard (miyeok) contains a high content of calcium and iodine, nutrients that are important for new nursing mothers.

[citation needed] Native to cold temperate coastal areas of Japan, Korea, China, and Russia,[5] in recent decades it has become established in temperate regions around the world, including New Zealand, the United States, Belgium,[6] France, Great Britain, Spain, Italy, Argentina, Australia and Mexico.

[9] Undaria is commonly initially introduced or recorded on artificial structures, where its r-selected growth strategy facilitates proliferation and spread to natural reef sites.

Undaria populations make a significant but inconsistent contribution of food and habitat to intertidal and subtidal reefs.

[27][28] Eradication of wakame within a localized area usually involves getting rid of the plants underwater, often via regular inspection of aquatic environments.

Its capability to grow in dense congregations on any hard surface allows it to outcompete native flora and fauna for sunlight and space.

[36] Even though it is an invasive species, farming of wakame is permitted in already heavily infested areas of New Zealand,[37] as part of a control program established since 2010.