Fucus spp. are the most common and conspicuous brown seaweeds (Phylum Phaeophyta) on the Pacific Northwest with the most common local species being Fucus gardneri. The name Fucus is derived from the Greek word for seaweed.
Description:
Fucus gardneri is a brown algae or seaweed, which can be olive-green or yellowish-green in colour. The blades are flat and dichotomously branched and some species have a distinct midrib. At Tower Beach Fucus gardneri grows up to 40 cm long and 25 cm wide. Each seaweed is attached to rocky substratum by a disc-shaped holdfast. Often you will find Fucus gardneri growing in clumps and during low tide they will lie on top of one another. When mature, the tips of the blades swell and fill with oxygen and mucus. These floats keep the algae upright when submerged in the water, enabling the interception of more light for photosynthesis. The small bumps visible on the tips of the blades are tiny cavities, in which eggs and sperm are produced.
Ecology:
Fucus gardneri form conspicuous olive-green bands on intertidal shores from Alaska to California. In sheltered to moderate wave exposed sites the bands form in the middle of the intertidal zone. The degree of wave exposure influences the size and shape of the algae.
The clumps of Fucus gardneri protect other algae and invertebrate from wave action and desiccation. The blades are also an important food source for grazers, such as limpets, isopods and littorine snails. Try to avoid walking on Fucus because it produces a mucus, which make the algae very slippery. This mucus protects the Fucus from desiccation during low tide, and can inhibit the larvae of other intertidal organisms (e.g. barnacles) from settling onto the blade's surface.
The clumps of Fucus gardneri protect other algae and invertebrate from wave action and desiccation. The blades are also an important food source for grazers, such as limpets, isopods and littorine snails. Try to avoid walking on Fucus because it produces a mucus, which make the algae very slippery. This mucus protects the Fucus from desiccation during low tide, and can inhibit the larvae of other intertidal organisms (e.g. barnacles) from settling onto the blade's surface.
To learn more:
Druehl, Louis D. 2000. Pacific Seaweeds. A guide to common seaweeds of the West Coast. Harbour Publishing, Madeira Park, B.C.
Sept. J. Duane. 1999. The Beachcomber's Guide to Seashore Life in the Pacific Northwest. Harbour Publishing, Madeira Park, B.C.
Snively, Gloria. 1978. Exploring the Seashore in British Columbia, Washington and Oregon. A Guide to Shorebirds and Intertidal Plants and Animals. Gordon Soules Book Publishers, Vancouver.
Waaland, J. Robert. 1977. Common Seaweeds of the Pacific Coast. J.J. Douglas Ltd. North Vancouver.