Olympic Coast National Marine Sanctuary Living Sanctuary section includes Marine Life, Habitats, Ocean Environment, History and Culture
Olympic Coast National Marine Sanctuary Living Sanctuary section includes Marine Life, Habitats, Ocean Environment, History and Culture
Olympic Coast National Marine Sanctuary Living Sanctuary section includes Marine Life, Habitats, Ocean Environment, History and Culture

Seaweed

mixed algaes Forests, grasslands, and marshes remind us of the importance of plants on our planet. They symbolize the fertility of our biosphere and the interconnectedness of living and non-living parts of the environment. And ultimately, they are the foundation of food chain that sustains human life on earth.

The ocean is similar, yet operates on a much vaster scale. Its plants, ranging from tiny plankton to massive kelps, also signify the amazing process of growth in the ocean ecosystem. Most ocean food chains, like those on land, begin with sunlight. Nutrients and minerals suspended in seawater feed explosive growth of plankton and seaweeds.

Common seaweeds of Olympic Coast National Marine Sanctuary include:

black pine algae Black Pine
Neorhodomela larix

Size: 30 cm to 12 inches tall
Habitat: Low intertidal
Phylum: Brown Algae
Caloric Value: Moderate, though it contains bromophenols that prevent some grazing.
Vegetation present year-round?: Yes
Reproduction: Separate male and female plants. Black Pine has two life cycles (one reproductive and one not) that are indistinguishable.
Notes: This species is more tolerant of sand than many other rocky intertidal algaes. It grows in mats and can out-compete other algae with its quick growth


bottle brush algae Bottlebrush Algae
Endocladia muricata

Size: 4-8 cm or 1.5 to 3 inches tall
Habitat: High tide zone; on rocks
Phylum: Red Algae
Caloric Value: High
Eaten by: Sometimes Limpets
Vegetation present year-round?: Yes
Reproduction: Bottlebrush algae has two life cycles (one reproductive and one not) that are indistinguishable.
Notes: Bottlebrush algae is well adapted to the high intertidal zone with a resistance to drying and the ability to withstand relatively high temperatures.


bull kelp Bull Kelp
Nereocystis leutkeana

Size: 10-36 meters or 33 feet to a record 118 feet.
Habitat: Low tide zone
Phylum: Brown Algae
Eaten by: Limpets, Chitons, and Urchins
Caloric Value: High, especially in protein, calcium and iron.
Vegetation present year-round?: Bull Kelp is usually ripped up by winter storms only to regrow in the spring.
Notes: The hollow bulb was used by coastal Native Americans to carry water; stems called stipes were dried and used for fishing line. It was also pickled and eaten by early pioneers.
- Kelp forests are shelter for fishes. Seabirds rest in calmed sea around the fronds. While, sea otters wrap in the blades to "anchor" themselves.
- The blades provide a hard surface for mussels and bryozoans to attach.
- One of the fastest growing plants- can grow up to half a foot a day, to a height of almost 100 feet!


coralline algae Coralline Algae
Order: Corallinales

Size: 1-2 mm, a thin coating
Habitat:- Low to mid tide zone
Phylum: Red algae
Eaten by: Northern Abalone, some limpets, and lined chitons
Vegetation present year-round?: Yes
Reproductions: Reproduction occurs within the algae. Sometimes, you can find small bumps on the surface of the algae where reproduction takes place. Separate male and female plants.
Notes: Coralline takes calcium out of the water. This calcium carbonate gives them a coral-like look. As they die, they turn white. There are a number of different species that are difficult to differentiate.


giant kelp Giant Kelp
Macrocystis pyrifera

Size: 30 meters or 100 feet long
Habitat: Low tide zone
Phylum: Brown algae
Eaten by: Red and Purple Urchins, Bat Star, Kelp Crab
Vegetation present year-round?: No. It dies off each winter, but grows back quickly in the early spring. Giant Kelp can grow up to 14 inches in one day, putting it in the running for fastest plant growth in the world.
Reproduces: Giant kelp releases spores into the water.
Notes: Giant Kelp and Bull Kelp are the key species in the kelp forests which stretch from Northern California to Alaska. Often plants are destroyed in winter storms and they grow back in the spring. Sanctuary studies show that Giant Kelp provides important breeding grounds and protection for young Rockfish and numerous other species.


laver algae Laver or Nori
Porphyra sp.

Size: Mid-size 10-50 cm or 4 to 20 inches long
Habitat: Mid tide zone
Phylum: Red algae
Caloric value: One of the highest caloric values for marine algae.
Eaten by: Limpets and other grazers
Vegetation present year round?: No
Reproduction: Very complex, two life cycles.
Notes: Cultivated worldwide as food. The alternate generation is a microscopic plant which grows inside the shells of marine mollusks like mussels and barnacles.


rockweed Rockweed
Fucus sp.

Size: 50 cm or 20 inches
Habitat: High to mid tide zone
Phylum: Brown algae
Caloric value: Moderate
Eaten by: Periwinkle snails, some limpets, and the Rockweed Isopod
Defense: Rockweed secretes polyphenols that inhibit digestion. These are especially active when parts of the seaweed is being grazed.
Vegetation present year-round: Yes
Reproduction: When eggs are released, a chemical encourages the release of sperm. Fertilized eggs quickly attach to rock.
Notes: Native Americans on the Olympic Peninsula discovered the gel inside the bulbs is useful to treat sunburns and cuts. Rockweed is not usually the first algae to settle in an area after a disturbance leaves rock bare. Grazing animals clear spots in the more aggressive algae, then rockweed find a place to settle.


sea cauliflower Sea Cauliflower
Leathesia difformis

Size: Up to 5 cm long, though usually smaller
Habitat: Mid to low tide zones
Caloric Value: Low
Phylum: Brown Algae
Vegetation present year-round?: Sea Cauliflower is an annual. It dies out in the winter.
Notes: Sea Cauliflower often settles on another plant and takes nothing from the host plant. Therefore, it is a true epiphyte. Sea Cauliflower does not tolerate high temperatures. It is often said to resemble a miniature brain.


sea lettuce Sea Lettuce
Ulva sp.

Size: 18 cm or 7 inches
Habitat: High tide zone; attached or free-floating
Phylum: Green algae
Caloric value: High
Eaten by: Shore crabs, Mollusks
Reproduction: Alternative generations (like ferns) produce one life stage that reproduces sexually and one that reproduces asexually.
Notes: Sea lettuce is one to two cells thick. The Danish species has been shown to absorb glucose and acetate from sea water, stimulating growth.


sea palms Sea Palms
Postelsia palmaeformis

Size: Up to 60 cm or 24 inches
Habitat: Grows in areas with extreme wave action. The flexible stems called stipes in seaweeds bend to absorb wave energy.
Phylum: Brown algae
Caloric value: Low
Vegetation present year-round?: No
Reproduction: Spores develop on the back side of the blades. They are released in late spring. Notes: Sea Palms can grow on mussels. This makes the mussels more susceptible to being pulled off rocks by wave action. New Sea Palms will then grow in to replace the missing mussels.


sea staghorn Sea Staghorn or Dead Man's Finger
Codium Fragile

Size: To 30 cm or 12 inches
Habitat: Grows on the outer coast in the low intertidal and subtidal zones.
Phylum: Green algae
Caloric value: Low
Eaten by: A specialized sea slug
Vegetation present year round?: Yes
Reproduction: Some plants are male and some female
Notes: Staghorn is a "siphonous alga" which means that it is composed of filaments that interweave and are in fact only one multinucleated cell. In the northeastern United States, a cyanobacteria has been found to live in Staghorn. This bacteria produces nitrogen for the plant. Further studies need to be done in the Northwest to see if that is true of the Staghorn that live here as well.


surfgrass Surfgrass
Pyllospadix sp

Size: Up to 1 meter or 3 feet
Habitat: Rocky areas, low intertidal Phylum: Sea grass
Caloric value: High
Vegetation present year-round?: Yes
Reproduction: Sea grass is a true plant. It has roots and flowers.
Notes: While it is a true plant, surfgrass does not have stomata (similar to pores) like terrestrial plants, This helps to prevent water loss in their salty environment. The outer wall of surfgrass is thickened to protect the plant. Surfgrass communities provide an important protected environment for intertidal life. Surfgrass is also high in protein. Because it plays an important biological role and it is sensitive to environmental changes, it is a keynote species.


winged kelp Winged Kelp
Alaria Marginata

Size: 2-3 meters or 8-10 feet
Habitat: Rocky intertidal, low tide zone
Phylum: Brown Algae
Vegetation present year round?: Yes
Reproduces: The reproductive sporophytes are low on the blade. They contain a chemical the discourages grazing.
Notes: Alaria tends to out-compete in areas of high-wave action.



Contact for page content: Robert Steelquist
Photo of peach coral
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