High Quality Content by WIKIPEDIA articles! Giant kelp, Macrocystis pyrifera, has been utilized for many years as a food source; it contains many compounds such as iodine, potassium, other minerals vitamins and carbohydrates and thus has also been used as a dietary supplement. In the beginning of the 20th century California kelp beds were harvested as a source for potash. With commercial interest increasing significantly during the 1970s and the 1980s this was primarily due to the production of alginates, and also for biomass production for animal feed due to the energy crisis during that period. However commercial production for M.pyrifera never became a reality. With the end of the energy crisis and the decline in prices of alginates, the research into farming Macrocystis also declined.