These kelp fronds are at the tip of a stalk of giant kelp (Macrocystis pyrifera) which is anchored to the ocean bottom and grows up toward the ocean surface. New growth such as this occurs at the tip of the stalk. Gas filled pneumatocysts provide bouyancy to the kelp plant, lifting it off the bottom and into the water column where it provides a home to many sea creatures. A veritable undersea forest.
Kelp frond showing pneumatocysts (air bladders).
Image ID: 03410
Species: Giant kelp, Macrocystis pyrifera
Location: San Clemente Island, California, USA