Ecosystems · Marine, North America

Pacific Coast Kelp Forests

Underwater forests of giant kelp along the Pacific coast.

Giant kelp is a fast-growing seaweed that forms towering underwater forests in cool, nutrient-rich water along the Pacific coast of North America. Kelp can grow dozens of centimetres in a day.

These forests shelter an enormous variety of fish, invertebrates and mammals.

The Landscape

Kelp anchors to rocky seabeds and reaches up to the surface in tall fronds, creating layers like a woodland canopy. Cold, upwelling water brings the nutrients that kelp needs.

Who Lives Here

Sea Otters are a keystone species, eating urchins that would otherwise graze kelp to bare rock. Garibaldi fish, Harbor Seals, Giant Pacific Octopus and many sea stars live among the fronds.

Through The Year

Kelp grows fastest in spring and early summer, and winter storms can tear fronds away. Warm water in some years weakens the forests, and tide-pooling is best at low spring tides.

Pressures And Care

Marine heatwaves, urchin population booms, sea star wasting disease, pollution and overfishing have caused major losses in some areas. Restoring predators and removing urchins are helping in places.

Visiting Well

Look from kayaks and shore, follow tide-pool etiquette, never remove animals from the water, and keep your distance from otters and seals.

Look for

Giant Kelp
Sea Otter
Garibaldi
Giant Pacific Octopus
Harbor Seal

Often a good time to visit: May, June, July. Conditions vary from year to year and place to place.

Related habitats

Coastal