Kelp Forests of California
A World Famous and Stunning Feature of the California Marine World
Sep 30, 2008
Much like the rainforests on land, the diversity of fish species and of the kelps themselves varies from the surface to the bottom. Kelp forests occur all over the world, and each can be split into three basic zones: the Canopy, Midwater, and Benthic zones.
The Canopy Zone: Land of the Giant Kelp
The canopy of the California kelp forest is dominated by the Giant kelp, Macrocystis pyrifera. Macrocystis is a brown algae that can grow up to three feet a day in the high growing seasons. Because it can grow so quickly it out-competes other species of kelp for space on the surface. Canopy kelps are kept afloat by gas filled floats called pneumatocysts.
As a perennial, this kelp persists through the year but experiences some "sloughing". Sloughing is where the weakened end of the kelp plant is broken off by waves and rough currents.
Examples of animals that live in the canopy are sea birds and otters. While they spend a majority of their time on the surface, they dive down into the lower layers of the forest in search of food.
The Midwater Zone: Fish Hub
The midwater zone is the largest of the kelp forest. It contains all the area between the surface and the bottom and so encompasses many more species of kelps and animals than other zones.
While canopy kelps are found in the zone above, stipate kelps rule in the midwater. Stipate kelps are those that grow upward from the bottom but do not reach the surface. Many stipate kelps are kept afloat by pneumatocysts, like the canopy kelps.
The midwater zone is home to the majority of the fish species of the kelp forest. Garibaldi is the most notable. As the California state marine fish they are protected and seem to know so. Divers will report that some Garibaldi will be so bold as to chase away a diver more than 10 times the size of the little fish! Other species found in this zone include the California Sheephead, Blacksmith, Senorita, and Opaleye.
The Benthic Zone: Domain of Invertebrates
The final zone of the kelp forest is the benthic zone, or benthos. This is where the last of the kelps are found, the prostrate kelps. Prostrate kelps lack any form of floatation like the canopy and stipate kelps. Because of this they grow out and lay on the bottom. Some kelps are capable of growing in depths of up to 130 feet deep.
The benthos is dominated by invertebrates living and thriving on any surface that they can. Common species of the benthos include the California Spiny Lobster, Coronado Sea Urchin, Warty Sea Cucumber, and Giant Keyhole Limpets.
Historically, this zone was the home to many species of abalone, but over fishing reduced their populations to near extinction levels. Due to state legislation and marine reserves the abalone populations have seen small improvements in the last few years. It is projected that with continued protection they will recover even more.
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