Kelp

photo by NOAA CC BY
Giant Kelp

Kelps are large seaweeds growing in underwater forests. Balls of spaghetti-like strands hold the seaweeds to the rocky sea bottom. Leaf-like structures called blades are attached to the stems, and gas-filled bladders keep kelp blades close to the surface. Kelps grow very quickly (6-10 in per day) but have a lifespan of only 200 days. The Kelps you spot on the shore are old and decaying.

Kelps often grow in dense kelp forests that provide food and shelter to over 800 marine animals and thousands of invertebrates. The greatest diversity of kelp forests are found from southern California to Alaska, but they are a common feature of all shallow oceans. When they grow close to land, they protect the shore from erosion by decreasing the impact of the waves.

The blades/leaves of Bull Kelps (northern California to Alaska) are attached to gas-filled balls that float on the surface of the water. Giant Kelps are the most common species of Kelp in southern California with blades (leaves) up to 200 ft long.

Did you know? Although there are similarities, Kelps are not plants. Seaweeds are algae, simple-bodied organisms that have combined with a bacteria containing a light-producing pigment that produces energy.