Kelp Forest
Off the coast, beyond the crashing surf, where the ebb and flow of the ocean currents bathe
shallow reefs, sways the majestic kelp.
Kelp occurs along coastlines that have an upwelling of cool, nutrient-rich waters, with temperatures
usually 68 degrees Fahrenheit. Dense stands of these brown algaes are called kelp forests.
These beautiful and biologically productive habitats are found in shallow, sunlit waters - usually less
than 30 meters deep - from the Arctic to the Antarctic Circles.
The bull kelp, scientifically known as Nereocystis, is one of the largest and fastest growing kelps
in the world, attaining astonishing growth rates of up to 10 inches a day. Bull kelp typically reach
lengths of 60 feet or more in a lifespan of 1-2 years.
The kelp plant is "anchored" to the seafloor by a root-like structure called a holdfast. At the
top of the holdfast grow stem-like stipes. These reach toward the surface with the help of a hollow
bulb, called a pneumatocyst. At the tip of the bulb are fronds, the function of which is to absorb
nutrients directly from the water column and gather light energy for photosynthesis. At the surface,
the fronds continue to grow, forming a dense canopy.
The canopy is teeming with juvenile fish and invertebrate larvae, which in turn may feed seabirds
such as the marbled murrelet, a threatened species along the Pacific Northwest coast. Other predators
in the kelp forest include the sea urchin. Population explosions of the herbivorous urchin can
decimate a kelp forest. At the top of the complex kelp forest food web is the sea otter, which can
help control the urchin numbers.
Native Americans had many uses for kelp, including medicine, food, salt, and fishing gear. Modern
day uses include the extraction of algin, which is used in everyday products such as paints,
synthetics, pharmaceuticals, rubber, beer and toothpaste.
June 1, 1834. The number of living creatures of all Orders, whose existence intimately depends
on the kelp, is wonderful. On shaking the great entangled roots, a pile of small fish, shells,
cuttlefish, crabs of all orders, sea-eggs, star-fish, beautiful crawling animals of a multitude
of forms, all fall out together. I can only compare these great acquatic forests with the ones in
the intertropical regions. Yet if in any country a forest was destroyed, I do not believe nearly
so many species of animals would perish as would from here, from the destruction of the kelp.
- Charles Darwin, "Voyage of the Beagle"
<Contact for page content: olympiccoast@noaa.gov
indicates a link leaves the site. Please view our