Seaweed

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Image:Seaweed 600.jpg Biologists, specifically Phycologists, consider seaweed to refer any of a large number of marine benthic algae that are multicellular, macrothallic, and thus differentiated from most algae that tend to be microscopic in size <ref> Smith, G.M. 1944. Marine Algae of the Monterey Peninsula, California. Stanford Univ., 2nd Edition.</ref>. Seaweeds are usually types of brown or red algae that are often found among other of algae, including green algae. There are a few species of cyanobacteria however, that may also be categorized as seaweeds. Named after terrestrial "weeds", Seaweeds are not to be confused with things like seagrasses, which are vascular plants and not algae.

1 Structure
2 Uses
3 See also
4 References
5 External links

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Structure

Image:Kelp forest Otago 1s.JPG Seaweeds may have an appearance that resembles non-arboreal terrestrial plants.

thallus: the algal body
- blade: a flattened structure that is somewhat leaf-like
  - sorus: spore cluster
  - on Fucus -- Air bladders: float-assist organ (on blade)
  - on kelp -- floats: float-assist organ (in between blade and stipe)
- stipe: a stem-like structure, may be absent
- holdfast: specialized basal structure providing attachment to the bottom

The stipe and blade are collectively known as frond.

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Uses

Seaweeds are extensively used as food by coastal peoples, particularly in Japan and Korea, but also in China, Vietnam, Indonesia, Peru, the Canadian Maritimes, Scandinavia, Ireland, Wales, Philippines, and Scotland, among other places. For example, Porphyra is a red alga used in Wales to make laverbread, and in Japan dried, formed into sheets called nori which is widely used in soups, and for wrapping sushi, boiled rice stuffed with bits of raw fish, sea urchin roe, or other ingredients. Chondrus crispus (commonly known as Irish moss) is another red alga used in producing various food additives.

Seaweed is also used for the production of Alginate, a versatile product that is used for many applications, including the production of Agar, which is used in microbiology as a substrate for culturing organisms. Alginates are also used in the production of foodstuffs to improve texture. Typical products which use alginates include ice-cream and a range of proprietary desserts (see Carrageenan).

Other seaweeds may be used as seaweed fertiliser.

Image:Fucus vesiculosus.JPG

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