Ascophyllum nodosum exposed to the sun in Nova Scotia, Canada

Dead Man's Fingers (Codium fragile) off Massachusetts coast

The top of a kelp forest in Otago, New Zealand

Seaweeds are any of a large number of marine plants and protists in the category of benthic algae. An ocean (from Greek, ''Okeanos'' (Oceanus) is a major body of saline water, and a principal component of the Hydrosphere. Protists (ˈproʊtɨst are a diverse group of eukaryotic Microorganisms Historically protists were treated as the kingdom Protista but this Benthos are the organisms which live on in or near the Seabed, also known as the Benthic zone. Algae ( sing. alga are a large and diverse group of simple typically Autotrophic organisms ranging from Unicellular to Multicellular forms They are macroscopic and multicellular, in contrast with most other algae. Multicellular organisms are Organisms consisting of more than one cell, and having Differentiated cells that perform specialized functions ^[1] Seaweeds are often found in the seashore biome. A biome is a climatically and geographically defined area of ecologically similar climatic conditions such as communities of Plants Animals and

Taxonomy

Seaweeds consist of several groups of multicellular algae: the red algae, green algae, and brown algae. Algae ( sing. alga are a large and diverse group of simple typically Autotrophic organisms ranging from Unicellular to Multicellular forms The red algae (Rhodophyta ˌroʊdəˈfaɪtə roʊˈdɒfɨtə from Greek: ῥόδον (rhodon = rose + φυτόν (phyton = plant thus red plant are The green algae (singular green alga) are the large group of Algae from which the Embryophytes (higher plants emerged The Phaeophyceae or brown algae, (singular alga is a large group of mostly marine multicellular Algae including many Seaweeds of colder As these three groups are not thought to have a common multicellular ancestor, the seaweeds are a paraphyletic group. In Phylogenetics, a group of organisms is said to be paraphyletic if the group contains its most recent common ancestor but does not contain all In addition, tuft-forming bluegreen algae (Cyanobacteria) are sometimes considered as seaweeds.

Seaweeds are popularly described as plants, but only red and green algae belong to the kingdom Plantae. In biological Taxonomy, a kingdom or regnum is a Taxonomic rank in either (historically the highest rank or (in the new three-domain system Plants are living Organisms belonging to the kingdom Plantae. They should not be confused with aquatic plants such as seagrasses (which are vascular plants). Aquatic plants &mdash also called hydrophytic plants or hydrophytes &mdash are plants that have adapted to living in or on aquatic environments Seagrasses (or sea-grasses in British English) are Flowering plants from one of four plant families ( Posidoniaceae, Zosteraceae, Vascular plants (also known as tracheophytes or higher plants) are those Plants that have lignified tissues for conducting

Structure

Seaweeds' appearance somewhat resembles non-arboreal terrestrial plants. Arboreal is a word meaning "related to or resembling trees" Plants are living Organisms belonging to the kingdom Plantae.

• thallus: the algal body
  • lamina: 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 (between lamina and stipe)
  • stipe: a stem-like structure, may be absent
  • holdfast: specialized basal structure providing attachment to a surface, often a rock or another alga. For the chronologer/historian occasionally mentioned in the works of early Christian writers see Thallus (historian. A Lamina in the Algae is a generally flattened structure which typically forms the principal bulk of macroscopic plants "Sori" redirects here For the commune in Italy see Sori Italy; for the villages in Azerbaijan see Soru and Sors Azerbaijan. In Biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions Fucus is a Genus of Brown alga ( Seaweed) in the Class Phaeophyceae to be found in the intertidal zones of rocky shores In Phytology, a pneumatocyst is a large float containing gas found in Brown algae. Kelp are large Seaweeds ( Algae) belonging to the Brown algae and classified in the order Laminariales In Phytology, a pneumatocyst is a large float containing gas found in Brown algae. In Botany, a stipe is a supportive structure that may be the stem-like part of the thallus of a Seaweed or a true leaf stem as in Ferns A holdfast is a Root -like structure that anchors aquatic Sessile organisms such as Seaweed, other sessile Algae, stalked
  • haptera: finger-like extensions of holdfast anchoring to benthic substrate

The stipe and blade are collectively known as fronds. A frond is a large Leaf with many divisions to it and the term is typically used for the leaves of palms Ferns or Cycads A frond is

Ecology

The ecology of seaweeds is dominated by two specific environmental requirements. These are the presence of sea-water (or at least brackish water) and the presence of light sufficient to drive photosynthesis. Photosynthesis is a Metabolic pathway that converts Light Energy into Chemical energy. A very common requirement is also to have a firm point of attachment. As a result, seaweeds are most commonly found in the littoral zone and within that zone more frequently on rocky shores than on sand or shingle. Littoral refers to the coast of an ocean or sea or to the banks of a river lake or estuary The ecological niches utilised by seaweeds are wide ranging. At the highest level are those that inhabit the zone that is only wetted by the tops of sea spray, the deepest living are those that are attached to the sea-bed under several meters of water. In some parts of the world, the area colonized by littoral seaweeds can extend for several miles away from the shore. The limiting factor in such cases is the availability of sufficient sun-light to support photosynthesis. The deepest living sea-weeds are the various kelps. Kelp are large Seaweeds ( Algae) belonging to the Brown algae and classified in the order Laminariales In addition to the familiar sea-shore seaweeds, a number of species have adapted to a fully planktonic niche and are free-floating, often with the assistance of gas filled sacs. Sargassum is one of the better known examples of this type of seaweed. Sargassum is a genus of generally planktonic (free-floating macroalgae ( Seaweed) in the order Fucales.

A number of species have adapted to the specialised environment of tidal rock pools. In this niche seaweeds are able to withstand rapidly changing temperature and salinity and even occasional drying. ^[2]

Uses

Food

Packaged seaweed

Seaweeds are extensively used as food by coastal peoples, particularly in East Asia, e. g. Japan, China, Korea, Taiwan, and Vietnam, but also in Indonesia, Peru, the Canadian Maritimes, Scandinavia, Ireland, Wales, Philippines, and Scotland, among other places. For a topic outline on this subject see List of basic Japan topics. China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National Korea is a geographic area composed of two sovereign countries a civilization and a former state situated on the Korean Peninsula in East Asia. Taiwan ( Taiwanese: Tâi-oân/Tāi-oân (historically 大灣/台員/大員/台圓/大圓/台窩灣 is an Island in East Asia. Vietnam (ˌviːɛtˈnɑːm Việt Nam) officially The Republic of Indonesia ( (Republik Indonesia is a Country in Southeast Asia. Peru (Perú Piruw Piruw officially the Republic of Peru ( reˈpuβlika del peˈɾu is a country in western South America. The Maritime provinces, called the Maritimes in local English (or the Canadian Maritimes by non-Canadians is a region of Eastern Canada Terminology and usage As a cultural term "Scandinavia" has no official definition and is subject to usage by those who identify with the culture in question as well Ireland (pronounced /ˈaɾlənd/ Éire) is the third largest island in Europe, and the twentieth-largest island in the world The Philippines ( Filipino: Pilipinas, officially known as the Republic of the Philippines (fil ''Republika ng Pilipinas'' RP Scotland ( Gaelic: Alba) is a Country in northwest Europethat occupies the northern third of the island of Great Britain. Tiwi, Albay residents discovered a new pansit or noodles made from seaweed, which has health benefits. Albay is a province of the Philippines A noodle is food made from unleavened Dough that is cooked in a boiling liquid It is rich in calcium and magnesium and the seaweed noodles can be cooked into pansit canton, pansit luglug, spaghetti or carbonara. Calcium (ˈkælsiəm is the Chemical element with the symbol Ca and Atomic number 20 Magnesium (mægˈniːziəm is a Chemical element with the symbol Mg, Atomic number 12 Atomic weight 24 Spaghetti is a long thin cylindrical Pasta of Italian origin A variety of pasta dishes are based on it from spaghetti with cheese and pepper or garlic and Pasta alla carbonara (usually Spaghetti, but occasionally Linguine or Bucatini) is an Italian Pasta dish based on eggs ^[3]

In Asia, gim (in Korea) and nori (in Japan) are sheets of dried Porphyra used in soups or to wrap sushi. Gim ( 김) sometimes spelled kim, is a Korean -style edible Seaweed in the genus Porphyra, similar Nori (海苔 ( 김 kim or gim) is the Japanese name for various edible Seaweed species of the Red alga Porphyra In Japanese cuisine, is Vinegared Rice, usually topped with other ingredients including fish various meats and vegetables Chondrus crispus (commonly known as Irish moss or carrageenan moss) is another red alga used in producing various food additives, along with Kappaphycus and various gigartinoid seaweeds. Chondrus crispus, known under the common name Irish moss, or carrageen moss ( Irish carraigín, "little rock" is a species Carrageenans or carrageenins (ˌkærəˈgiːnənz are a family of linear sulphated Polysaccharides extracted from red Seaweeds The name is derived from Porphyra is a red alga used in Wales to make laver and laverbread, made from oats and the laver, is a popular dish in Wales. Porphyra is a foliose Red algal genus of laver, comprising approximately 70 species Laver is an edible Seaweed that has a high Mineral salt content particularly Iodine and Iron. REDIRECT Laver (seaweed#Laverbread

Seaweeds are also harvested or cultivated for the extraction of alginate, agar and carrageenan, gelatinous substances collectively known as hydrocolloids or phycocolloids. Alginic acid ( algin, alginate) is a viscous gum that is abundant in the cell walls of Brown algae. Agar or agar agar is a Gelatinous substance derived from Seaweed. Carrageenans or carrageenins (ˌkærəˈgiːnənz are a family of linear sulphated Polysaccharides extracted from red Seaweeds The name is derived from A colloid is a type of mechanical Mixture where one substance is dispersed evenly throughout another Hydrocolloids have attained commercial significance, especially in food production as food additives. ^[4] The food industry exploits the gelling, water-retention, emulsifying and other physical properties of these hydrocolloids. Agar is used in foods such as confectionery, meats and poultry products, desserts and beverages and moulded foods. Carrageenan is used in preparation of salad dressings and sauces, dietetic foods, and as a preservative in meat and fish products, dairy items and baked goods. Alginates enjoy many of the same uses as carrageenan, but are also used in production of industrial products such as paper coatings, adhesives, dyes, gels, explosives and in processes such as paper sizing, textile printing, hydro-mulching and drilling.

Medicine

In the biomedicine and pharmaceutical industries, alginates are used in wound dressings, and production of dental moulds and have a host of other applications. Biomedicine, also known as theoretical medicine, is a term that comprises the knowledge and research which is more or less in common to the fields of human medicine In microbiology research, agar is extensively used as culture medium. Microbiology (from Greek grc μῑκρος mīkros, "small" grc βίος bios, " Life " and grc -λογία Carrageenans, alginates and agaroses (the latter are prepared from agar by purification), together with other lesser-known macroalgal polysaccharides, also have several important biological activities or applications in biomedicine. Seaweed is also a known source of iodine,^[5] an element necessary for thyroid function with deficiencies leading to goitre. Iodine (ˈaɪədaɪn ˈaɪədɪn or /ˈaɪədiːn/ from ιώδης iodes "violet" is a Chemical element that has the symbol I and Atomic The thyroid is one of the largest Endocrine glands in the body A goitre ( BrE) or goiter ( AmE) ( Latin struma) also called a bronchocele, is a swelling in the neck (just below the It has been asserted that seaweeds may have curative properties for tuberculosis, arthritis, colds and influenza, worm infestations and even tumors. Tuberculosis (abbreviated as TB for tubercle bacillus or T u' b' erculosis Bacillus --> is a common Arthritis (from Greek arthro-, joint + -itis, inflammation plural arthritides is a group of conditions involving damage to the Joints of the body See also Cancer A tumor or tumour is the name for a swelling or lesion formed by an abnormal growth of cells (termed neoplastic [1] A number of research studies have been conducted to investigate these claims and other effects of seaweed on human health.

See also Fucoidan

Other uses

Other seaweeds may be used as seaweed fertilizer. Fucoidan is a Sulfated Polysaccharide ( MW: average 20000 found mainly in various species of brown Seaweed such as Kombu, Limu Seaweed fertilizer, also spelt seaweed fertiliser, is a valuable addition to the Organic garden, and is abundantly available for free for those living

Seaweed-covered rocks in the UK

References

See also

External links

• The Seaweed Site, information on all aspects of seaweeds and marine algal biology
• AlgaeBase, a searchable taxonomic, image, and utilization database of freshwater, marine and terrestrial algae, including seaweed. See also Algae Algaculture is a form of Aquaculture involving the farming of species of Algae. Alaria esculenta is an edible Seaweed, also known as dabberlocks or badderlocks, or winged Kelp. Ascophyllum nodosum is a large common Brown alga, in the Class Phaeophyceae. See also Algology Algae fuel, also called algal fuel, oilgae, algaeoleum or third generation biofuel, is a Biofuel Chondrus crispus, known under the common name Irish moss, or carrageen moss ( Irish carraigín, "little rock" is a species Caulerpa is a genus of Seaweeds in the family Caulerpaceae (among the Green algae. Dunaliella salina is a type of Halophile pink micro- Algae especially found in sea salt fields Kelp are large Seaweeds ( Algae) belonging to the Brown algae and classified in the order Laminariales Laminaria is a Genus of 31 Species of Brown algae ( Phaeophyceae) all sharing the common name " Kelp " Laver is an edible Seaweed that has a high Mineral salt content particularly Iodine and Iron. In taxonomy, Monostroma is a genus of Algae, specifically of the Monostromataceae. Ogonori ( Gracilaria spp also called ogo or sea moss, is a type of edible Seaweed eaten along the coasts of Japan, Palmaria palmata (L Kuntze also called dulse, dillisk, dilsk or creathnach, is a Red alga ( Rhodophyta) previously Porphyra is a foliose Red algal genus of laver, comprising approximately 70 species Scytosiphon lomentaria is a Littoral brown Seaweed with an irregularly lobed many filamentous form The sea lettuces comprise the Genus Ulva, a group of edible Green algae widely distributed along the coasts of the world's Oceans In Botany, Trentepohlia is a genus of filamentous green chlorophyte Algae, specifically of the family Trentepohliaceae, living Undaria pinnatifida, is a type of edible Kelp. History in the West In 1867 the word "wakame" first appeared in an English-language publication
• SeaweedAfrica, information on seaweed utilisation for the African continent.