This is a passage of an NPR story about California kelp. May someone expand on the WWI use of kelp in gun powder?
Harvesting kelp in California for commercial purposes is not unprecedented. “They did have these large boats that gave the kelp a haircut, harvesting kelp along the California coast,” Kim explains. During World War I, kelp was used to make gunpowder. By the 1960s, a company in San Diego harvested kelp to make products like alginate, which is a solidifying agent in ice cream and cosmetics.