One of the largest algae in the world, giant bladder kelp forms an extensive offshore submarine forest which supports an abundance of animal life. The kelp itself is also harvested for a product called "algin" which is used in many different commercial products. Large rafts of the alga commonly pile up on shore after winter storms.

The root-like holdfast can grow to about 20 inches in diameter in a very mature plant. The stipe bears a number of yellow-brown wrinkled blades, each of which has an air sac at its base.