Kelp are large seaweeds, belonging to the brown algae and classified in the order Laminariales. Despite their appearance they are not grouped with the normal aquatic or land plants (kingdom Plantae), but instead are included in either kingdom Protista or Chromista. There are about 30 different genera. Some larger members of the order Fucales are also included by some within the general term Kelp. Kelp grows in underwater forests (kelp forests) in clear, shallow, oceans, requiring nutrient rich water below about 20°C, it offers a protection to some sea creatures, or food for others. It is known for its high growth rate - the genus Macrocystis grows up to 30 cm per day, to a total length of over 60 metres.

Morphology

---

In most Kelp the thallus(or body), consists of flat or leaf-like structures known as blades. Blades originate from elongate, stem-like structures, the stipes. The holdfast, a root-like structure anchors the Kelp to the substrate of the ocean. Gas-filled bladders (pneumatocysts) form at the base of most blades and keep the Kelp blades close to the surface.

Uses

---

Kelp ash is rich in iodine and alkali. In great amount, kelp ash can be used in soap and glass production. Alginate, a kelp-derived carbohydrate, is used to thicken products like ice cream, jelly, salad dressing, and toothpaste, as well as in manufactured goods.

Prominent species

---

• bull-head kelp (Nereocystis luetkeana), a northwestern American species. Used by coastal indigenous peoples to create fishing nets.
• giant kelp (Macrocystis pyrifera), the largest seaweed. Found in the Pacific coast of North America and South America.
• kombu (Laminaria japonica), an edible species of kelp found in Japan.

Species of the British Isles

---

• Laminaria digitata (Hudson) J.V. Lamouroux (Oarweed; Tangle)
• Laminaria hyperborea (Gunnerus) Foslie (Curvie)
• Laminaria ochroleuca Bachelot de la Pylaie
• Laminaria saccharina (Linnaeus) J.V.Lamouroux (Sea Belt; Sugar Kelp; Sugarwack)

  Interactions

  ---

  Some animals are named after the kelp, either because they inhabit the same habitat as kelp or because they feed on kelp. These include:
  • Kelp crab (Pugettia producta), the Pacific coast of North America.
  • Kelpfish (blenny) (e.g., Heterosticbus rostratus, genus Gibbonsia), the Pacific coast of North America.
  • Kelp Goose (kelp hen) (Ocydromus fuscus), South America and the Falkland Islands
  • kelp pigeon (sheathbill) (Chionis sp), Antarctic

  See also

  ---

  • Kelp forest
  • bladder wrack
  • Kelp Records
  • KeLP programing system
  • Monterey Bay Aquarium, which displays a kelp forest and its wildlife.

  Brown algae | Sea vegetables

  Kelp | Kelp | Kombu | コンブ | Kelp