Flipping through the winter 2005 issue of Blue Planet Quarterly from The Ocean Conservancy, I found a great article about giant kelp that details the importance of the critters in the world.

Kelp
Giant kelp is found in the cooler waters of North America, southern Africa, southern Australia, and the west coast of America. It is used in a variety of food, industrial, pharmaceutical and cosmetic products. Chances are you have some in your fridge right now. One kelp harvesting and processing company based in California estimates that 80,000 tons of kelp will be harvested each year during this decade.

During its peak growing season, kelp can grown up to 2 feet per day. All of this makes kelp sustainable and economically significant to the economy.

Who eats the kelp and who eats those who eat the kelp
The near extinction of southern sea otter from southern Califonia waters (The southern sea otter was listed as “threatened” under the federal Endangered Species Act (ESA) in 1977) gave way to a growing population of sea urchins. Without the sea otters, there were fewer critters to eat the sea urchins and the sea urchins decimated the kelp forests, leaving them urchin barren.

Bye, bye ecosystem
Without the kelp, other animals who rely upon the kelp for food and habitat left the area.

But what can I do?
For more information on threats to the ocean and what you can do check out The Ocean Conservancy,