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Seaweed has been consumed by coastal marine-based civilizations all over the world since the dawn of human existence.
In its dried state it could be preserved for long periods of time, providing a storehouse of vital nutrition that was light weight and easy to transport.
Seaweed has been used extensively throughout history as natural fertilizers for land based food crops to increase production and nutritive content.
Sea vegetables became especially popular in the Western world with the macrobiotic health movement, that was made infamous by the Japanese teacher George Ohsawa in the 1960's.
Kelp grows in "underwater forests" in shallow oceans, and is thought to have appeared in the Miocene, 23 to 5 million years ago.
The organisms require nutrient-rich environent with temperatures between 6 and 14 °C (43 and 57 °F). It is known for its high growth rate - the genera Macrocystis and Nereocystis can grow as fast as half a metre a day, ultimately reaching 30 to 80 metres (100 to 260 ft).