Carrageenan carrageenan were estimated at $640 million. The largest producer of industrial carrageenan was the Philippines, where cultivated seaweed produces about 80% of the world supply, while China is the main exporter to global markets in the US and Europe. The most commonly used sources are "E. cottonii" ("Kappaphycus alvarezii", "K. striatum") and "E. spinosum" ("Eucheuma denticulatum"), which together provide about three-quarters of the world production. These grow from the sea surface to a depth of about 2 metres. The seaweed is normally grown on nylon lines strung between bamboo floats, and it is harvested after three months or so, when
Red algae contain the sulfated polysaccharide carrageenan in the amorphous sections of their cell walls, although red algae from the genus Porphyra contain porphyran. They also produce a specific type of tannin called phlorotannins, but in lower amount than brown algae do. Complete genome sequences are only available for 6 species of red algae, including 4 published in 2013. One of the oldest fossils identified as a red alga is also the oldest fossil eukaryote that belongs to a specific modern taxon. "Bangiomorpha pubescens", a multicellular fossil from arctic Canada, strongly resembles the modern red alga "Bangia" despite occurring in rocks dating