Seaweed

Seaweed
Informal group of macroscopic marine algae
"Fucus serratus"
Fucus serratus
Scientific classification
Domain: Eukaryota, Bacteria
Seaweeds can be found in the following groups
Ascophyllum nodosum
Ascophyllum nodosum exposed to the sun in Nova Scotia, Canada
Codiumfragile
Dead man's fingers (Codium fragile) off the Massachusetts coast in the United States
Kelp forest Otago 1s
The top of a kelp forest in Otago, New Zealand

Seaweed or macroalgae refers to several species of macroscopic, multicellular, marine algae.[1] The term includes some types of red, brown, and green macroalgae. Marine algae species such as kelps provide essential nursery habitat for fisheries and other marine species and thus protect food sources; ocean algae species from seaweeds to planktons play a vital role in carbon capture, producing up to 90 percent of the planet's oxygen. Understanding these roles provides guiding principles for conservation and sustainable use of seaweeds to take precedence over industrial exploitation. Mechanical dredging of kelp, for instance, destroys the resource and dependent fisheries. Certain species of seaweed are valuable for nutrition, biomedicine, bioremediation, and other uses.

Taxonomy

"Seaweed" is a colloquial term and lacks a formal definition. A seaweed may belong to one of several groups of multicellular algae: the red algae, green algae, and brown algae. As these three groups do not have a common multicellular ancestor, the seaweed are in a polyphyletic group. In addition, some tuft-forming bluegreen algae (Cyanobacteria) are sometimes considered to be seaweed.

Structure

Seaweed's appearance somewhat resembles non-arboreal terrestrial plants.

  • thallus: the algal body
    • lamina or blade: a flattened structure that is somewhat leaf-like
      • sorus: a spore cluster
      • on Fucus, air bladder: a flotation-assisting organ on the blade
      • on kelp, float: a flotation-assisting organ between the lamina and stipe
    • stipe: a stem-like structure, may be absent
    • holdfast: a specialized basal structure providing attachment to a surface, often a rock or another alga
    • haptera: a finger-like extension of the holdfast anchoring to a benthic substrate

The stipe and blade are collectively known as the frond.

Ecology

NSW seabed 2
Seaweed cover this rocky seabed on the east coast of Australia

Two specific environmental requirements dominate seaweed ecology. These are the presence of seawater (or at least brackish water) and the presence of light sufficient to drive photosynthesis. Another common requirement is a firm attachment point, although some genera such as Sargassum and Gracilaria have species that float freely. As a result, seaweed most commonly inhabit the part of a sea that is close to the shore (the littoral zone) and within that zone more frequently on rocky shores than on sand or shingle. Seaweed occupy a wide range of ecological niches. The highest elevation is only wetted by the tops of sea spray, the lowest is several meters deep. In some areas, littoral seaweed can extend several miles out to sea. The limiting factor in such cases is sunlight availability. The deepest living seaweed are some species of red algae.

Others have adapted to live in tidal rock pools. In this habitat, seaweed must withstand rapidly changing temperature and salinity and even occasional drying.[2]

Uses

Seaweed has a variety of purposes, for which it is farmed[3] or foraged from the wild.[4]

At the beginning of 2011, Indonesia produced 3 million tonnes of seaweed and surpassed the Philippines as the world's largest seaweed producer. By 2011, the production was estimated to have reached 10 million tonnes.[5]

Onigiri at an onigiri restaurant by zezebono in Tokyo

Onigiri and wakame miso soup, Japan

Laver and toast

Laverbread and toast

Seaweed Farms in Indonesia

Small plots being used to farm seaweed in Indonesia, with each rectangle belonging to a different family

Food

Seaweed is consumed by coastal people, particularly in East Asia, e.g. Japan, China, Korea, Taiwan, and Southeast Asia, e.g. Brunei, Singapore, Thailand, Burma, Cambodia, Vietnam, Indonesia, Philippines, and Malaysia, and also in South Africa, Belize, Peru, Chile, the Canadian Maritimes, Scandinavia, South West England,[6] Ireland, Wales, California, and Scotland.

In Asia, Gim (Korean food) (김, Korea), nori (海苔, Japan), zicai (紫菜, China) are sheets of dried Porphyra used in soups, sushi wrap or onigiri (rice balls). Chondrus crispus (commonly known as 'Irish moss' or carrageenan moss) is another red alga used in producing food additives, along with Kappaphycus and gigartinoid seaweed. Porphyra is a red alga used in Wales to make laverbread. Laverbread, made from the seaweed, and sometimes also with oat flour, is a popular dish there. In northern Belize, edible seaweed are mixed with milk, nutmeg, cinnamon, and vanilla to make a common beverage affectionately called "dulce" (or "sweet").

Seaweed are also harvested or cultivated for the extraction of alginate, agar and carrageenan, gelatinous substances collectively known as hydrocolloids or phycocolloids. Hydrocolloids have attained commercial significance as food additives.[7] The food industry exploits their gelling, water-retention, emulsifying and other physical properties. Agar is used in foods such as confectionery, meat and poultry products, desserts and beverages and moulded foods. Carrageenan is used in salad dressings and sauces, dietetic foods, and as a preservative in meat and fish products, dairy items and baked goods.

The development of seaweed as an alternative and sustainable source of food and animal feed ingredients depends on the sustainability of the natural resource of raw biomass and on moving the process of feed development from laboratory to industrial scale.[8]

Medicine and herbalism

Seaweed 600
Seaweed-covered rocks in the United Kingdom
Seaweed on rocks at Atlantic Ocean
Seaweed on rocks in Long Island

Alginates are commonly used in wound dressings (see alginate dressing), and production of dental moulds. In microbiology research, agar – a plant-based jelly similar to gelatin and made from seaweed – is extensively used as culture medium. Carrageenans, alginates and agaroses (the latter are prepared from agar by purification), with other lesser-known macroalgal polysaccharides, have several important biological activities or applications in biomedicine. Research suggests that the Australian seaweed Delisea pulchra may interfere with bacterial colonization.[9] Sulfated saccharides from both red and green algae have been known to inhibit some DNA and RNA enveloped viruses.[10]

Seaweed extract is used in some diet pills.[11] Other seaweed pills exploit the same effect as gastric banding, expanding in the stomach to make the body feel more full.[12][13]

Filtration

The strong photosynthesis of algae creates a large affinity for nutrients; this allows the seaweed to be used purposely to remove undesired nutrients from water. Nutrients such as ammonia, ammonium nitrate, nitrite, phosphate, iron, copper, as well as CO2 are rapidly consumed by growing seaweed. Reefs and lakes are naturally filtered this way (the seaweed being consumed by fish and invertebrates), and this filtering process is duplicated in artificial seaweed filters such as algae scrubbers.

Modern floating surface algae scrubber filter, floating on top of aquarium
Modern floating algae scrubber/cultivator on a reef pond

Seaweed (macroalgae), as opposed to phytoplankton (microalgae), is used almost universally for filtration purposes because of the need to be able to easily remove (harvest) the algae from the water, which then removes the nutrients. Microalgae require more processing to separate it from the water than macroalgae does; macroalgae is simply pulled out.

When used for filtration, saltwater algae commonly grows species of Cladophora, Ulva (sea lettuce), and Chaetomorpha. Freshwater filtration applications are useful, too, and will commonly grow species such as Spirogyra.

Other uses

Other seaweed may be used as fertilizer, compost for landscaping, or a means of combating beach erosion through burial in beach dunes.[14]

Seaweed is under consideration as a potential source of bioethanol.[15][16]

Harvesting (cleaning) algae that has grown in an algae scrubber
Seaweed is lifted out of top of algae scrubber/cultivator, to be discarded or used as food, fertilizer, or skin care

Alginates enjoy many of the same uses as carrageenan and are used in industrial products such as paper coatings, adhesives, dyes, gels, explosives and in processes such as paper sizing, textile printing, hydro-mulching and drilling. Seaweed is an ingredient in toothpaste, cosmetics and paints.[3] Seaweed is also used for the production of bioyarn (a textile).[17]

Seaweed may provide excellent opportunities for their industrial exploitation if sustainable without destroying habitat, as they could be a source of multiple compounds (i.e. polysaccharides, proteins and phenols) with applications such as food [18][8] and animal feed,[8] pharmaceuticals [10] or fertilizers.

Seaweed collecting is the process of collecting, drying and pressing seaweed. It was a popular pastime in the Victorian era and remains a hobby today. In some emerging countries, Seaweed is harvested daily to support communities.

Gift of the Ocean
Women in Tanzania grow "Mwani" (seaweed in Swahili). The farms are made up of little sticks in neat rows in the warm, shallow water. Once they harvest the seaweed, it is used for many purpose: food, cosmetics, fabric, etc.

Seaweed is sometimes used to build roofs on houses on Læsø in Denmark [19]

Seaweeds are also used as animal feeds. They have long been grazed by sheep, horses and cattle in Northern Europe. They are currently particularly valuable for fish production.[20] Adding seaweed to livestock feed can substantially reduce methane emissions from cattle.[21]

Health risks

Rotting seaweed is a potent source of hydrogen sulfide, a highly toxic gas, and has been implicated in some incidents of apparent hydrogen-sulphide poisoning.[22] It can cause vomiting and diarrhea.

The stinging seaweed Microcoleus lyngbyaceus contains several known toxins including lyngbyatoxin-a and debromoaplysiatoxin. Direct skin contact can cause seaweed dermatitis characterized by painful, burning lesions that subsist for several days. [23] [24]

Genera

Claudea elegans tetrasporangia
Claudea elegans tetrasporangia

The following table lists a very few example genera of seaweed.

Genus Algae Phylum Remarks
Caulerpa Caulerpa prolifera Green Submerged
Fucus Fucus serratus2 Brown In intertidal zones on rocky shores.
Gracilaria Gracilaria2 Red Cultivated for food
Laminaria Laminaria hyperborea - Köhler–s Medizinal-Pflanzen-214 Brown Also known as kelp, 8–30 m under water, cultivated for food.
Macrocystis Giantkelp2 300 Brown Giant kelp, forming floating canopies.
Monostroma Seaweed-farmer Green
Porphyra Porphyra yezoensis Red Intertidal zones in temperate climate. Cultivated for food.

See also

References

  1. ^ Smith, G.M. 1944. Marine Algae of the Monterey Peninsula, California. Stanford Univ., 2nd Edition.
  2. ^ Lewis, J.R. 1964. The Ecology of Rocky Shores. The English Universities Press Ltd.
  3. ^ a b "Seaweed farmers get better prices if united". Sun.Star. 2008-06-19. Retrieved 2008-07-16.
  4. ^ "Springtime's foraging treats". The Guardian. London. 2007-01-06. Retrieved 2008-07-16.
  5. ^ "RI aims to become world's largest seaweed producer". Waspada.co.id. 2011-04-16. Retrieved 2012-06-28.
  6. ^ "Devon Family Friendly - Tasty Seaweed Recipe - Honest!". BBC. 2005-05-25. Retrieved 2012-06-28.
  7. ^ Round F.E. 1962 The Biology of the Algae. Edward Arnold Ltd.
  8. ^ a b c Garcia-Vaquero, M.; Hayes, M. (2016). "Red and green macroalgae for fish and animal feed and human functional food development". Food Reviews International. 32: 15–45. doi:10.1080/87559129.2015.1041184.
  9. ^ Francesca Cappitelli & Claudia Sorlini (2008). "Microorganisms attack synthetic polymers in items representing our cultural heritage". Applied and Environmental Microbiology. 74 (3): 564–569. doi:10.1128/AEM.01768-07. PMC 2227722. PMID 18065627.
  10. ^ a b Kazłowski B; Chiu YH; Kazłowska K; Pan CL; Wu CJ (August 2012). "Prevention of Japanese encephalitis virus infections by low-degree-polymerisation sulfated saccharides from Gracilaria sp. and Monostroma nitidum". Food Chem. 133 (3): 866–74. doi:10.1016/j.foodchem.2012.01.106.
  11. ^ Hayato Maeda, Masashi Hosokawa, Tokutake Sashima, Katsura Funayama & Kazuo Miyashita (2005). "Fucoxanthin from edible seaweed, Undaria pinnatifida, shows antiobesity effect through UCP1 expression in white adipose tissues". Biochemical and Biophysical Research Communications. 332 (2): 392–397. doi:10.1016/j.bbrc.2005.05.002. PMID 15896707.CS1 maint: Multiple names: authors list (link)
  12. ^ "New Seaweed Pill Works Like Gastric Banding". Fox News.
  13. ^ Elena Gorgan (6 January 2009). "Appesat, the Seaweed Diet Pill that Expands in the Stomach". softpedia.
  14. ^ Rodriguez, Ihosvani (April 11, 2012). "Seaweed invading South Florida beaches in large numbers". South Florida Sun-Sentinel. Retrieved 2012-04-11.
  15. ^ "Seaweed Power: Ireland Taps New Energy Source". alotofyada.blogspot.co.uk. 2008-06-24. Retrieved 9 April 2018.
  16. ^ Chen, Huihui; Zhou, Dong; Luo, Gang; Zhang, Shicheng; Chen, Jianmin (2015). "Macroalgae for biofuels production: Progress and perspectives". Renewable and Sustainable Energy Reviews. 47: 427–437. doi:10.1016/j.rser.2015.03.086.
  17. ^ The promise of Bioyarn from AlgiKnit
  18. ^ Garcia-Vaquero, M; Rajauria, G; O'Doherty, JV; Sweeney, T (2017). "Polysaccharides from macroalgae: Recent advances, innovative technologies and challenges in extraction and purification". Food Research International. 99 (Pt 3): 1011–1020. doi:10.1016/j.foodres.2016.11.016. hdl:10197/8191. PMID 28865611.
  19. ^ "Seaweed Thatch". naturalhomes.org. Retrieved 9 April 2018.
  20. ^ Heuzé V., Tran G., Giger-Reverdin S., Lessire M., Lebas F., 2017. Seaweeds (marine macroalgae). Feedipedia, a programme by INRA, CIRAD, AFZ and FAO. https://www.feedipedia.org/node/78 Last updated on May 29, 2017, 16:46
  21. ^ "Seaweed shown to reduce 99% methane from cattle". irishtimes.com. Retrieved 9 April 2018.
  22. ^ "Algues vertes: la famille du chauffeur décédé porte plainte contre X" AFP, retrieved 2010-04-22 (in French)
  23. ^ https://www.cabdirect.org/cabdirect/abstract/19822902103 "Escharotic stomatitis caused by the "stinging seaweed" Microcoleus lyngbyaceus (formerly Lyngbya majuscula): case report and literature review"
  24. ^ https://onlinelibrary.wiley.com/doi/full/10.1111/j.1365-4632.2011.05042.x "Lyngbya dermatitis (toxic seaweed dermatitis)"

Further reading

  • Christian Wiencke, Kai Bischof [editors]: Seaweed Biology: Novel Insights into Ecophysiology, Ecology & Utilization. Springer, 2012. ISBN 978-3-642-28450-2 (print); ISBN 978-3-642-28451-9 (eBook)

External links

Brown algae

The brown algae (singular: alga), comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Most brown algae live in marine environments, where they play an important role both as food and as habitat. For instance, Macrocystis, a kelp of the order Laminariales, may reach 60 m (200 ft) in length and forms prominent underwater kelp forests. Kelp forests like these contain a high level of biodiversity. Another example is Sargassum, which creates unique floating mats of seaweed in the tropical waters of the Sargasso Sea that serve as the habitats for many species. Many brown algae, such as members of the order Fucales, commonly grow along rocky seashores. Some members of the class, such as kelps, are used by humans as food.

Between 1,500 and 2,000 species of brown algae are known worldwide. Some species, such as Ascophyllum nodosum, are important in commercial use because they have become subjects of extensive research in their own right. They have environmental significance as well, through carbon fixation.Brown algae belong to the group Heterokontophyta, a large group of eukaryotic organisms distinguished most prominently by having chloroplasts surrounded by four membranes, suggesting an origin from a symbiotic relationship between a basal eukaryote and another eukaryotic organism. Most brown algae contain the pigment fucoxanthin, which is responsible for the distinctive greenish-brown color that gives them their name. Brown algae are unique among heterokonts in developing into multicellular forms with differentiated tissues, but they reproduce by means of flagellated spores and gametes that closely resemble cells of other heterokonts. Genetic studies show their closest relatives to be the yellow-green algae.

Carrageenan

Carrageenans or carrageenins ( karr-ə-gee-nənz, from Irish carraigín, "little rock") are a family of linear sulfated polysaccharides that are extracted from red edible seaweeds. They are widely used in the food industry, for their gelling, thickening, and stabilizing properties. Their main application is in dairy and meat products, due to their strong binding to food proteins. There are three main varieties of carrageenan, which differ in their degree of sulfation. Kappa-carrageenan has one sulfate group per disaccharide, iota-carrageenan has two, and lambda-carrageenan has three.

Gelatinous extracts of the Chondrus crispus (Irish moss) seaweed have been used as food additives since approximately the fifteenth century. Carrageenan is a vegetarian and vegan alternative to gelatin in some applications or may be used to replace gelatin in confectionery.

Caulerpa lentillifera

Caulerpa lentillifera is a species of bryopsidale green algae from coastal regions in the Indo-Pacific. This seaweed is one of the favored species of edible Caulerpa due to its soft and succulent texture. C. lentillifera is farmed and eaten in the Philippines, where it is locally known under various names including latô and arosep; in the Malaysian state of Sabah, where it is known as latok and a popular dish among the Bajau peoples; in Okinawa, Japan, where it is known as umi-budō (海ぶどう), meaning "sea grapes"; and in Vietnam, where it is known as rong nho or rong nho biển, meaning "grape algae" or "seagrape algae". It is sometimes known in English as green caviar or sea grapes (along with the related Caulerpa racemosa). In Indonesia, and in particular Bali, it is known as bulung.

Caulerpa lentillifera is usually eaten raw with vinegar, as a snack or in a salad. In the Philippines, after being washed in clean water, it is usually eaten raw as a salad, mixed with chopped raw shallots and fresh tomatoes, and dressed with a blend of fish sauce or bagoong (fish paste) and vinegar. It is known to be rich in iodine.

Several health benefits have been reported for Caulerpa lentillifera including diabetes and lipid lowering properties.The pond cultivation of C. lentillifera has been very successful on Mactan Island, Cebu, in the central Philippines, with markets in Cebu and Manila. About 400 ha of ponds are under cultivation, producing 12–15 tonnes of fresh seaweed per hectare per year.

Edible seaweed

Edible seaweed, or sea vegetables, are algae that can be eaten and used in the preparation of food. They typically contain high amounts of fiber. They may belong to one of several groups of multicellular algae: the red algae, green algae, and brown algae.Seaweeds are also harvested or cultivated for the extraction of polysaccharides such as alginate, agar and carrageenan, gelatinous substances collectively known as hydrocolloids or phycocolloids. Hydrocolloids have attained commercial significance, especially in food production as food additives. The food industry exploits the gelling, water-retention, emulsifying and other physical properties of these hydrocolloids.Most edible seaweeds are marine algae whereas most freshwater algae are toxic. Some marine algae contain acids that irritate the digestion canal, while some others can have a laxative and electrolyte-balancing effect. Most marine macroalgae are nontoxic in normal quantities, but members of the genus Lyngbya are potentially lethal. Typically poisoning is caused by eating fish which have fed on Lyngbya or on other fish which have done so. This is called ciguatura poisoning. Handling Lyngbya majuscula can also cause seaweed dermatitis. Some species of Desmarestia are highly acidic, with vacuoles of sulfuric acid that can cause severe gastrointestinal problems.The dish often served in western Chinese restaurants as 'Crispy Seaweed' is not seaweed but cabbage that has been dried and then fried.

Eucheuma

Eucheuma, commonly known as gusô, is a seaweed algae that may be brown, red, or green in color. Eucheuma species are used in the production of carrageenan, an ingredient for cosmetics, food processing, and industrial manufacturing, as well as a food source for people in Indonesia and the Philippines. Eucheuma cottonii – cultivated in the Philippines – is the particular species known as gusô. Other species include Betaphycus gelatinae, Eucheuma denticulatum, and several species of the genus Kappaphycus, including K. alvarezii. Since the mid-1970s, Kappaphycus and Eucheuma have been a major source for the expansion of the carrageenan industry.Though commercially significant, species of Eucheuma are difficult to identify without the aid of close scientific examination, as different species may have similar morphologies. Some eighteen to twenty species alone fall within the genus Eucheuma, represented by the groups Cottoniformia, Gelatiformia, and Anaxiferae.Gusô is listed in the Ark of Taste international catalogue of endangered heritage foods of the Philippines by the Slow Food movement.

Food play

Food play can have sexual or non-sexual connotations. The term often refers to sitophilia, a form of sexual fetishism in which participants are aroused by erotic situations involving food. The phrase is also used to refer to non-sexual play with food, such as playful and decorative food displays, enjoyment of preparing food, or even a play about food. This article refers to the sitophilia connotation of food play.

Some foods and herbs themselves are purported to cause sexual arousal in and of themselves. Food play overlaps with other fetishes, including wet and messy fetishism, feederism, and nyotaimori. It is differentiated from vorarephilia (often shortened to "vore") in that food play fetishizes food while vore fetishizes the act of eating a living creature, or being eaten alive.

Hairspray (1988 film)

Hairspray is a 1988 American dance comedy film written and directed by John Waters, and starring Ricki Lake, Divine, Debbie Harry, Sonny Bono, Jerry Stiller, Leslie Ann Powers, Colleen Fitzpatrick, and Michael St. Gerard. Hairspray was a dramatic departure from Waters's earlier works, with a much broader intended audience. Hairspray's PG is the mildest rating a Waters film has received; most of his previous films were rated X by the MPAA. Set in 1962 Baltimore, Maryland, the film revolves around self-proclaimed "pleasantly plump" teenager Tracy Turnblad as she pursues stardom as a dancer on a local TV show and rallies against racial segregation.

Hairspray was only a moderate success upon its initial theatrical release, earning a modest gross of $8 million. However, it managed to attract a larger audience on home video in the early 1990s and became a cult classic. Most critics praised the film, although some were displeased with the overall campiness. The film ranks #444 on Empire magazine's 2008 list of the 500 greatest movies of all time.In 2002, the film was adapted into a Broadway musical of the same name, which won eight Tony Awards, including Best Musical in 2003. A second film version of Hairspray, an adaptation of the stage musical, was also released by New Line Cinema in 2007, which included many changes of scripted items from the original.

Laverbread

Laverbread () is a food product, made from an edible seaweed (littoral alga), consumed mainly in Wales as part of local traditional cuisine. The seaweed is commonly found around the west coast of Great Britain and east coast of Ireland along the Irish Sea, where it is known as slake. It is smooth in texture and forms delicate, sheetlike thalli, often clinging to rocks. The principal variety is Porphyra umbilicalis. Porphyra (laver seaweed) is classified as red algae; it tends to be a brownish colour, but boils down to a dark green pulp when prepared. Laver seaweed has a high content of dietary minerals, particularly iodine and iron. The high iodine content gives the seaweed a distinctive flavour in common with olives and oysters.

Laver seaweed has been cultivated as a food since at least the 17th century. It is prepared by washing repeatedly and then boiled until it becomes a soft mush when it is known as laverbread. The gelatinous paste that results can then be sold as it is, or rolled in oatmeal; it is sometimes coated with oatmeal prior to frying. Laverbread is traditionally eaten fried with bacon and cockles as part of a Welsh breakfast, or with hog's pudding in the south west of England.

Limu o Pele

Limu o Pele or Pele's seaweed (Hawaiian, literally, "seaweed of Pele", after Pele the Hawaiian fire goddess of volcanoes) is a geological term for thin sheets and subsequently shattered flakes of brownish-green to near-colourless volcanic glass lava spatter that commonly resemble seaweed in appearance, that have been erupted from a volcano. Limu o Pele is formed when water is forced into and trapped inside lava, as when waves wash over the top of the exposed flows of the molten rock. The water boils and is instantly converted to steam, expanding to form bubbles within the lava. The lava rapidly cools and solidifies as the bubbles grow. The volcanic glass bubbles burst and are dispersed by the wind, showering flakes of glass downwind.

Limu o Pele has been found around subaerial littoral volcanic cones and also at submarine volcanoes, for example, on the summit of Lōʻihi seamount.

Nori

Nori (海苔) is the Japanese name for edible seaweed (a "sea vegetable") species of the red algae genus Pyropia, including P. yezoensis and P. tenera. It has a strong and distinctive flavor. It is used chiefly in Japanese cuisine as an ingredient to wrap rolls of sushi or onigiri, in which case the term refers to the dried sheets.

The finished dried sheets are made by a shredding and rack-drying process that resembles papermaking. They are sold in packs in grocery stores for culinary purposes. Since nori sheets easily absorb water from the air and degrade, a desiccant is needed when storing nori for any significant time.

The Academy of Nutrition and Dietetics established in 2016 that nori is not an adequate source of vitamin B12. Nori also contains toxic metals (arsenic and cadmium) and amphipod allergens, so its daily consumption in large quantities is discouraged.

North Ronaldsay sheep

The North Ronaldsay or Orkney is a breed of sheep from North Ronaldsay, the northernmost island of Orkney, off the north coast of Scotland. It belongs to the Northern European short-tailed sheep group of breeds, and has evolved without much cross-breeding with modern breeds. It is a smaller sheep than most, with the rams (males) horned and ewes (females) mostly hornless. It was formerly kept primarily for wool, but now the two largest flocks are feral, one on North Ronaldsay and another on the Orkney island of Linga Holm. The Rare Breeds Survival Trust lists the breed as "vulnerable", with fewer than 600 registered breeding females in the United Kingdom.

The semi-feral flock on North Ronaldsay is the original flock that evolved to subsist almost entirely on seaweed – they are one of few mammals to do this. They are confined to the shoreline by a 1.8 m (6 ft) tall drystane dyke, which completely encircles the island, forcing the sheep to evolve this unusual characteristic. The wall was built as kelping (the production of soda ash from seaweed) on the shore became uneconomical. Sheep were confined to the shore to protect the fields and crofts inside, and afterwards subsisted largely on seaweed.

This diet has caused a variety of adaptations in the sheep's digestive system. These sheep have to extract the trace element copper far more efficiently than other breeds as their diet has a limited supply of copper. This results in them being susceptible to copper toxicity, if fed on a grass diet, as copper is toxic to sheep in high quantities. Grazing habits have also changed to suit the sheep's environment. To reduce the chance of being stranded by an incoming tide, they graze at low tide and then ruminate at high tide.

A range of fleece colours are exhibited, including grey, brown and red. Meat from the North Ronaldsay has a distinctive flavour, described as "intense" and "gamey", due, in part, to the high iodine content in their diet of seaweed. The meat has Protected Geographical Status in European Union law, so only meat from North Ronaldsay sheep can be marketed as Orkney Lamb.

Nuru (massage)

Nuru is a Japanese erotic massage technique from Kawasaki, Japan. The technique requires one or more nuru masseuses to rub their body against the client's body after both parties are nude and covered with an odorless and colourless massage lotion made predominantly from the Nori seaweed. The word originates from the Japanese language and means "slippery / smooth." Nuru practitioners use an odorless and tasteless massage lotion which is derived from seaweed leaves, sometimes referred to as "nuru gel" in English. The gel is applied by hand to the entire body of both client and masseuse. During the massage, participants will try to get the widest possible physical contact, the masseuses often using their entire body on the person to be treated. Strong tactile sensations are triggered that are designed to relieve stress. The main component of the gel used during Nuru massages is the sulfated polysaccharide fucoidan, which is obtained from the leaves of the brown seaweed plant Sphaerotrichia divaricata. Chamomile, Azulene and other minerals are often added.

Often, Nuru massages are finished with a sexual act. Along with other forms of sex work, nuru massages are legal in rural areas in Nevada, US.

Pancit

In Filipino cuisine, pancit are noodles. Noodles were introduced into the Philippines early on by Chinese Filipino settlers in the archipelago, and over the centuries have been fully adopted into local cuisine, of which there are now numerous variants and types. The term pancit is derived from the Hokkien pian i sit (Chinese: 便ê食; Pe̍h-ōe-jī: piān-ê-si̍t or Chinese: 便食; pinyin: biàn shí) which literally means "convenient food." Different kinds of noodles can be found in Filipino supermarkets which can then be cooked at home. Noodle dishes are also standard fare in local restaurants. Food establishments specializing in noodles are often referred to as panciterias.

Nancy Reyes Lumen of the Philippine Center for Investigative Journalism writes that according to food lore handed down from the Chinese, noodles should be eaten on one's birthday. They are therefore commonly served at birthday celebrations and Chinese restaurants in the Philippines often have "birthday noodles" listed on their menus. However, she warns that since "noodles represent long life and good health", they must not be cut, as that would "corrupt the symbolism."Pancit is a derivative of a type of noodle(s) that originated in China but pancit which is different in its own aspect originated in the Philippines. The fact that pancit is eaten and part of Filipino culture means that it was most likely brought over from settlers originating in China or East Asia.

Sargasso Sea

The Sargasso Sea () is a region of the North Atlantic Ocean bounded by four currents forming an ocean gyre. Unlike all other regions called seas, it has no land boundaries. It is distinguished from other parts of the Atlantic Ocean by its characteristic brown Sargassum seaweed and often calm blue water.The sea is bounded on the west by the Gulf Stream, on the north by the North Atlantic Current, on the east by the Canary Current, and on the south by the North Atlantic Equatorial Current, a clockwise-circulating system of ocean currents termed the North Atlantic Gyre. It lies between 70° and 40° W, and 20° to 35° N, and is approximately 1,100 km wide by 3,200 km long (700 by 2,000 statute miles). Bermuda is near the western fringes of the sea.All the currents deposit the marine plants and refuse they carry into this sea, yet the ocean water in the Sargasso Sea is distinctive for its deep blue color and exceptional clarity, with underwater visibility of up to 61 m (200 ft). It is also a body of water that has captured the public imagination, and so is seen in a wide variety of literary and artistic works and in popular culture.

Sargassum

Sargassum is a genus of brown (class Phaeophyceae) macroalgae (seaweed) in the order Fucales. Numerous species are distributed throughout the temperate and tropical oceans of the world, where they generally inhabit shallow water and coral reefs, and the genus is widely known for its planktonic (free-floating) species. Most species within the class Phaeophyceae are predominantly cold-water organisms that benefit from nutrients upwelling, but the genus Sargassum appears to be an exception. Any number of the normally benthic species may take on a planktonic, often pelagic existence after being removed from reefs during rough weather; however, two species (S. natans and S. fluitans) have become holopelagic—reproducing vegetatively and never attaching to the seafloor during their lifecycles. The Atlantic Ocean's Sargasso Sea was named after the algae, as it hosts a large amount of Sargassum.

Seaweed (band)

Seaweed is an American band from Tacoma, Washington who were active throughout the 1990s. Their style of music is a combination of punk rock and grunge.

Seaweed farming

Seaweed farming is the practice of cultivating and harvesting seaweed. In its simplest form, it consists of the management of naturally found batches. In its most advanced form, it consists of fully controlling the life cycle of the algae. The main food species grown by aquaculture in Japan, China and Korea include Gelidium, Pterocladia, Porphyra, and Laminaria. Seaweed farming has frequently been developed as an alternative to improve economic conditions and to reduce fishing pressure and over exploited fisheries. Seaweeds have been harvested throughout the world as a food source as well as an export commodity for production of agar and carrageenan products.

Tideline

A tideline refers to where two currents in the ocean converge. Driftwood, floating seaweed, foam, and other floating debris may accumulate, forming sinuous lines called tidelines (although they generally have nothing to do with the tide).

There are four mechanisms that can cause tidelines to form:

Where one body of water is sinking beneath or riding over top of the surface layer of another body of water (somewhat similar in mechanics to subduction of the earth plates at continental margins). These types of tidelines are often found where rivers enter the ocean.

Along the margins of back-eddies.

Convergence zones associated with internal gravity waves.

Along adjacent cells formed by wind currents.

Wakame

Wakame (ワカメ), Undaria pinnatifida, is a species of edible seaweed, a type of marine algae, and a sea vegetable. It has a subtly sweet, but distinctive and strong flavour and texture. It is most often served in soups and salads.

Sea farmers in Japan have grown wakame since the Nara period. As of 2018, the Invasive Species Specialist Group has listed the species on its list of 100 worst globally invasive species.

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