Found in cool water along the western shores of the Pacific Ocean, this brown algae can grow to a length over 100 feet. In water not much deeper than 60 feet, it spreads along the surface to form a canopy. It’s held down on the rocky bottom with a structure called a holdfast. This kelp is heavily harvested along the California coast for a derivative called algin that is used in a multitude of products. Photo courtesy of Tom Haight.