| "The number of living creatures of all orders whose existence intimately depends on kelp is wonderful...I can only compare those great aquatic forests...with terrestrial ones in the intertropical regions. Yet if in any country a forest was destroyed, I do not believe nearly so many species would perish as would here from the destruction of kelp" Thus commented Charles Darwin on kelp. Pterygophora californica ( commonly known as stalked kelp) is part of the great kelp family that act as the trees of the oceans. This species is present, amongst other places, at Race Rocks.
Like other kelp species, this one can mostly be found in subtidal zones. It occurs in subtidal zones mostly up to 12 meters of depth. It is mostly found therefore in subsurface canopies of kelp forests. For this reason it is able to live well around the islands of Race Rocks.
The Stalked Kelp grows up to 2 meters in length. It has a straight or gnarled, woody undivided stalk and smooth , straplike blades extending on opposite sides from the top half of the stalk . The end of the stalk results in a terminal blade with midrib and the stalk develops rings as the years go by similar to those of a tree. Pterygophora is an excellent example of a long -lived perennial seaweed. The blades usually degenerate or wear away in winter and new ones are produced each spring. Often, violent winter storms tear up some of the anchored kelp and deposit it on beaches as in the photo above.
Stalked kelp can reach an age over 17 years. It is possible to find out the exact age of a stalked kelp plant by cutting it down and counting the rings in its stalk. At Race Rocks this type of kelp provides habitat for a number of fish and invertebrates and a large community of epiphytic algae.
Reference:
Guide to Common Seaweeds of British Columbia, by R.F Scagel, Printed by K.M Macdonald,1972
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