It’s amazing how fast bull kelp (Nereocystis luetkeana) can grow, sometimes up to 10 inches (25.4 cm) per day! As a diver below looking upward it can be an awe-inspiring sight to witness sunlight streaming through the kelp forest canopy above.
Bull kelp is an annual seaweed. It grows from a spore to full maturity in a single year. At the base of the kelp is a holdfast that attaches to the rocks below. From here a flexible stem shoots upward to the surface and is supported by a gas filled float. Many long golden fronds grow from this float making a large canopy near the surface of the ocean. This seaweed can grow to 118 feet (36 m) long. Its range is from northern Alaska to southern California.