National Geographic: A boy swims in algae-covered waters off the coast of Qingdao, China (map) in 2011-just one of the places around the world where algae blooms are a growing problem. elated pictures: "Photos: Thick Green Algae Chokes Beach-Swimmers Dive In.")
With an estimated seven billion people and counting, the world's population will only get hungrier. The advent of fertilizers and high-yield crops have helped growers keep pace with the demand for food.
But there's an unintended crop flourishing around the...