Subtidal Community

Kelp: a macro algal community

Kelp beds are one of the richest habitats in the Strait of Georgia because they provide food and shelter for a variety of animals. Plants, fishes, and invertebrates gather and interact within kelp beds. For example, sea urchins graze on kelp blades and herring spawn on them. Kelp crabs live on kelp beds and rockfishes hide amongst the kelp, as salmon hunt for food.

Kelp Forest Photo retrieved from the NOAA National Marine Fisheries Service at <http://www.nmfs.noaa.gov/habitat/habitatprotection/index4.htm>

Rocks give kelp a place to attach their holdfasts. The kelp canopy can block up to 90 percent of the sunlight from above. Many kelps are seasonal, growing quickly when there is plenty of summer sunlight.

There is often reproductive activity taking place in a kelp bed, from seastars producing large amounts of sperm and eggs to rockfishes giving birth to live young.

Kelp beds are often the sites of fierce competition as various animals compete for the limited resources of food or space. Kelp greenling and lingcod can be seen establishing and maintaining their territories near the kelp. They will chase away intruders and flare their fins at fish that get too close.

Many animals have amazing adaptations that help them avoid being eaten. The red urchin's spines, the red rock crab's shell, the schooling of Pacific herring, or the camouflage of the starry flounder and cabezon are all excellent examples.

For hundreds of years, kelp has been harvested by people for food. Today it is primarily harvested for its natural gel called algin. You have probably eaten kelp in ice cream, toothpaste, or the foam on a beer. Kelp is also used for pharmaceuticals, paints, make-up, mulch, and fertilizer. Kelp is a valuable commodity for both humans and animals.

Subtidal Fishes

Salmon (see Highlighted Species: Salmon)

Rockfish (see Highlighted Species: Rockfish)

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