Kelp

Taxobox
name =Kelp


image_width = 270px
image_caption = Californian kelp forest
domain = Eukaryota
regnum = Chromalveolata
phylum = Heterokontophyta
classis = Phaeophyceae
ordo = Laminariales
ordo_authority = Migula
subdivision_ranks = Families
subdivision =
Alariaceae

Chordaceae

Laminariaceae

Lessoniaceae

Phyllariaceae

Pseudochordaceae

Kelp are large seaweeds (algae), belonging to the brown algae and classified in the order Laminariales. There are about 30 different genera. Some species grow very long indeed, and form kelp forests.

Despite their plant-like appearance, some scientists group them not with the terrestrial plants (kingdom Plantae), but instead place them either in kingdom Protista or in kingdom Chromista.

Kelp grows in underwater "forests" (kelp forests) in clear, shallow oceans. It requires nutrient-rich water below about 20 °C (68 °F). It is known for its high growth rate — the genus "Macrocystis" and "Nereocystis luetkeana" grow as fast as half a metre a day, ultimately reaching 30 to 80 m.Thomas, D. 2002. "Seaweeds." The Natural History Museum, London, p. 15. ISBN 0 565 09175 1]

Through the 19th century, the word "kelp" was closely associated with seaweeds that could be burned to obtain soda ash (primarily sodium carbonate). The seaweeds used included species from both the orders Laminariales and Fucales. The word "kelp" was also used directly to refer to these processed ashes. ["Kelp," in [http://www.oed.com "Oxford English Dictionary (Second Edition)] ." Oxford University Press, 1989. Retrieved 1 December 2006]

Morphology

In most kelp, the thallus (or body) consists of flat or leaf-like structures known as blades. Blades originate from elongated 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 blades of American species, such as "Nereocystis lueteana" (Mert.& Post & Rupr.) and keep the kelp blades close to the surface, holding up the leaves by the gas they contain.

Growth and reproduction

Growth occurs at the base of the meristem, where the blades and stipe meet. Growth may be limited by grazing. Sea urchins, for example, can reduce entire areas to urchin barrens. The kelp life cycle involves a diploid sporophyte and haploid gametophyte stage. The haploid phase begins when the mature organism releases many spores, which then germinate to become male or female gametophytes. Sexual reproduction then results in the beginning of the diploid sporophyte stage which will develop into a mature plant.

Commercial uses

Bongo kelp ash is rich in iodine and alkali. In great amount, kelp ash can be used in soap and glass production. Until the Leblanc process was commercialized in the early 1800s, burning of kelp in Scotland was one of the principal industrial sources of soda ash (predominantly sodium carbonate).Clow, Archibald and Clow, Nan L. (1952). "Chemical Revolution." Ayer Co Pub, June 1952, pp. 65–90. ISBN 0-8369-1909-2] Alginate, a kelp-derived carbohydrate, is used to thicken products such as ice cream, jelly, salad dressing, and toothpaste, as well as an ingredient in exotic dog food and in manufactured goods. Giant kelp can be harvested fairly easily because of its surface canopy and growth habit of staying in deeper water.

Kelp is also used frequently in seaweed fertiliser, especially in the Channel Islands, where it is known as "vraic".

Kombu ("Laminaria japonica" and others), several Pacific species of kelp, is a very important ingredient in Japanese cuisine. Kombu is used to flavor broths and stews (especially "dashi"), as a savory garnish ("tororo konbu") for rice and other dishes, as a vegetable, and a primary ingredient in popular snacks (such as "tsukudani"). Transparent sheets of kelp ("oboro konbu") are used as an edible decorative wrapping for rice and other foods. [Kazuko, Emi: "Japanese Cooking", p. 78, Hermes House, 2002, p. 78. ISBN 0-681-32327-2 ]

Kombu can be used to soften beans during cooking, and to help convert indigestible sugars and thus reduce flatulence. [Graimes, Nicola: "The Best-Ever Vegetarian Cookbook", Barnes & Noble Books, 1999, p. 59. ISBN 0-7607-1740-0]

Because of its high concentration of iodine, brown kelp (Laminaria) has been used to treat goiter, an enlargement of the thyroid gland caused by a lack of iodine, since medieval times. [ [http://newswise.com/articles/view/541835/ Iodine Helps Kelp Fight Free Radicals and May Aid Humans, Too] Newswise, Retrieved on July 8, 2008.]

Kelp in history and culture

During the Highland Clearances, many Scottish Highlanders were moved off their crofts, and went to industries such as fishing and kelping (producing soda ash from the ashes of kelp). At least until the 1820s, when there were steep falls in the price of kelp, landlords wanted to create pools of cheap or virtually free labour, supplied by families subsisting in new crofting townships. Kelp collection and processing was a very profitable way of using this labour, and landlords petitioned successfully for legislation designed to stop emigration. But the economic collapse of the kelp industry in northern Scotland led to further emigration, especially to North America.

Natives of the Falkland Islands are sometimes nicknamed "Kelpers" [ [http://www.allwords.com/word-Kelper.html] allwords.com definition for "Kelper",] [ [http://dictionary.reference.com/browse/kelper] dictionary.com definition for "Kelper"] . The name is primarily applied by outsiders rather than the natives themselves.

See the article on seaweed fertiliser.

Endangerment

Overfishing nearshore ecosystems leads to the degradation of kelp forests. Herbivores are released from their usual population regulation, leading to over-grazing of kelp and other algae. This can quickly result in barren landscapes where only a small number of species can thrive.

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" and others, several edible species of kelp found in Japan.

Species of "Laminaria" in 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)

pecies of "Laminaria" world-wide

A comprehensive listing of species in [http://www.algaebase.org/taxonomy.lasso?id=4586&-session=abv3:48E46E6A1d71e0CB2DjYi1914543 "Laminariales"] and nearly all other algae orders is publicly accessible at http://www.algaebase.org. [Guiry, M.D. & Guiry, G.M. 2006. [http://algaebase.org AlgaeBase] version 4.2. World-wide electronic publication, National University of Ireland, Galway. Retrieved 7 December 2006]
* "Laminaria agardhii" (NE. America)
* "Laminaria angustata" (Japan)
* "Laminaria bongardina" Postels et Ruprecht (Bering Sea to California)
* "Laminaria cuneifolia" (NE. America)
* "Laminaria dentigera" Klellm. (California - America)
* "Laminaria digitata" (NE. America)
* "Laminaria ephemera" Setchell (Sitka, Alaska, to Monterey County, California - America)
* "Laminaria farlowii" Setchell (Santa Cruz, California, to Baja California - America)
* "Laminaria groenlandica" (NE. America)
* "Laminaria japonica" (Japan)
* "Laminaria longicruris" (NE. America)
* "Laminaria nigripes" (NE. America)
* "Laminaria ontermedia" (NE. America)
* "Laminaria pallida" Greville ex J. Agardh (South Africa)
* "Laminaria platymeris" (NE. America)
* "Laminaria saccharina" (Linnaeus) Lamouroux (Aleutian Islands, Alaska to southern California America)
* "Laminaria setchellii" Silva (Aleutian Islands, Alaska to Baja California America)
* "Laminaria sinclairii" (Harvey ex Hooker f. ex Harvey) Farlow, Anderson et Eaton (Hope Island, British Columbia to Los Angeles, California - America)
* "Laminaria solidungula" (NE. America)
* "Laminaria stenophylla" (NE. America)

Other genera in the Laminariales which may be considered as kelp

* "Alaria marginata" Post. & Rupr. (Alaska and California - America
* "Costaria costata" (C.Ag.) Saunders Japan; Alaska, California - America)
* "Durvillea antarctica" (New Zealand, South America, and Australia)
* "Durvillea willana" (New Zealand)
* "Durvillaea potatorum" (Labillardière) Areschoug (Tasmania; Australia)
* "Ecklonia brevipes" J. Agardh (Australia; New Zealand)
* "Ecklonia maxima" (Osbeck) Papenfuss (South Africa)
* "Ecklonia radiata" (C.Agardh) J. Agardh (Australia; Tasmania; New Zealand; South Africa)
* "Eisena arborea" Aresch. (Vancouver Island, British Columbia, Montrey, Santa Catalina Island, California - America)
* "Egregia menziesii" (Turn.) Aresch.
* "Hedophyllum sessile (C.Ag.) Setch (Alaska, California - America)
* "Macrocystis angustifolia" Bory (Australia; Tasmania and South Africa)
* "Pleurophycus gardneri" Setch. & Saund. (Alaska, California - America)
* "Pterygophora californica" Rupr. (Vancouver Island, British Columbia to Bahia del Ropsario, Baja California and California - America)

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:
* Northern kelp crab ("Pugettia producta") and graceful kelp crab ("Pugettia gracilis"), Pacific coast of North America.
* Kelpfish (blenny) (e.g., "Heterosticbus rostratus", genus "Gibbonsia"), Pacific coast of North America.
* Kelp goose (kelp hen) ("Chloephaga hybrida"), South America and the Falkland Islands
* Kelp pigeon (sheathbill) ("Chionis alba" and "Chionis minor"), Antarctic

References

ee also

* Kelp forest
* Bladder wrack
* KeLP programming system
* Monterey Bay Aquarium, which displays a kelp forest and its wildlife.
* Durvillea

External links

External links

* [http://www.seavitaminsandmarinenutrition.com/seaweed-video.php Underwater Seaweed Video]