giant kelp

brown algae

Also known as: Macrocystis pyrifera

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June 29, 2026

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Giant kelp refers to very large, fast-growing species of brown algae belonging to the genus Macrocystis. These seaweeds can reach lengths of over 150 feet (45 meters) and are found in cooler ocean waters. They form dense underwater forests that provide crucial habitat and food for many marine organisms. Giant kelp has a complex structure with a root-like holdfast, a stem-like stipe, and long, buoyant blades containing gas bladders. These algae are also a source of algin, a substance used in various industrial and food products.1234

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Pelagophycus
…at the outer fringe of giant kelp (Macrocystis pyrifera) forests, which occur at comparatively shallow depths. Elk kelp, however, can hybridize naturally with giant kelp, and certain hybrid gametophytes produced from this crossing may be fertile. Both elk and giant kelp provide important habitats for other marine life, including other…
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…at the outer fringe of giant kelp (Macrocystis pyrifera) forests, which occur at comparatively shallow depths. Elk kelp, however, can hybridize naturally with giant kelp, and certain hybrid gametophytes produced from this crossing may be fertile. Both elk and giant kelp provide important habitats for other marine life, including other…
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marine ecosystem
Benthos
…day to its length—is the giant kelp, Macrocystis pyrifera, which is found on subtidal rocky reefs. These plants, which may exceed 30 metres in length, characterize benthic habitats on many temperate reefs. Large laminarian and fucoid algae are also common on temperate rocky reefs, along with the encrusting (e.g., Lithothamnion)…
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…day to its length—is the giant kelp, Macrocystis pyrifera, which is found on subtidal rocky reefs. These plants, which may exceed 30 metres in length, characterize benthic habitats on many temperate reefs. Large laminarian and fucoid algae are also common on temperate rocky reefs, along with the encrusting (e.g., Lithothamnion)…
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kelp
Giant kelps of the genus Macrocystis are the largest known kelp species, with lengths of one species, the giant bladder kelp (M. pyrifera), reaching 60 metres (197 feet) or more. The genus is limited in distribution because it reproduces only at temperatures below 18–20 °C…
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Giant kelps of the genus Macrocystis are the largest known kelp species, with lengths of one species, the giant bladder kelp (M. pyrifera), reaching 60 metres (197 feet) or more. The genus is limited in distribution because it reproduces only at temperatures below 18–20 °C…
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Otters, Algae, and Plants, Oh My
Otters, Algae, and Plants, Oh My transcript
…one species of kelp called giant kelp, Macrocystis pyrifera. They’re found pretty much all along Eastern Pacific from California to Alaska as well as in parts in Australia, New Zealand, South America, even some parts of the Atlantic, which is pretty cool. Giant kelp, as well as the other group…
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…one species of kelp called giant kelp, Macrocystis pyrifera. They’re found pretty much all along Eastern Pacific from California to Alaska as well as in parts in Australia, New Zealand, South America, even some parts of the Atlantic, which is pretty cool. Giant kelp, as well as the other group…
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