Kelp farms are farm locations where seaweed is grown and harvested. In fictional worlds, kelp farms or other aquatic means of food cultivation may help feed an underwater civilization. Kelp is rich in iodine and alkali and kelp ash can be used for soap and glass production. Kelp also contains alginate, a natural thickening agent used in products like ice cream, jelly, and toothpaste. Kelp is also a food and can be eaten raw or cooked. Wild kelp may be kelp forests.