All Topics  
Algae

 

   Email Print
   Bookmark   Link

 

Algae


 
 


Algae (sing. alga) are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms. The largest and most complex marine forms are called seaweed
Biologists, specifically marine biologists, consider seaweed to be any of a large number of marine benthic algae that ...
s. They are photosynthetic
Photosynthesis , generally, is the synthesis of sugar from light, carbon dioxide and water, with oxygen as a waste product....
, like plants, and "simple" because they lack the many distinct organs found in land plants. Though the prokaryotic
Prokaryotes are organisms without a cell nucleus , or indeed any other membrane-bound organelles, in most cases unicellula...
 cyanobacteria
Cyanobacteria is a phylum of Bacteria that obtain their energy through photosynthesis....
(commonly referred to as blue-green algae) were traditionally included as "algae" in older textbooks, many modern sources regard this as outdated and restrict the term algae to eukaryotic
|-| style = "background: pink; padding: 4px;" | Animalia - Animals...
 organisms. All true algae therefore have a nucleus enclosed within a membrane and chloroplast
Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis....
s bound in one or more membranes. as they do not all descend from a common algal ancestor, although their chloroplasts seem to have a single origin.

Algae lack the various structures that characterize land plants, such as phyllids and rhizoids in nonvascular plants, or leaves
In botany, a leaf is an above-ground plant organ specialized for photosynthesis....
, root
In vascular plants, the root is that organ of a plant body that typically lies below the surface of the soil ....
s, and other organs
In biology, an organ is a group of tissues that perform a specific function or group of functions....
 that are found in tracheophytes. They are distinguished from protozoa
Protozoa are single-celled eukaryotes that commonly show characteristics usually associated with animals, most notably mob...
 in that they are photosynthetic. Many are photoautotrophic, although some groups contain members that are mixotrophic
The term mixotrophic can describe organisms capable of deriving metabolic energy both from photosynthesis and from external ...
, deriving energy both from photosynthesis and uptake of organic carbon either by osmotrophy
Osmotrophy is the uptake of dissolved organic compounds by osmosis for nutrition....
, myzotrophy
Myzocytosis is a method of feeding found in some heterotrophic organisms....
, or phagotrophy
Phagocytosis is a form of endocytosis wherein large particles are enveloped by the cell membrane of a cell and internalized ...
. Some unicellular species
In biology, a species is one of the basic units of biodiversity....
 rely entirely on external energy sources and have limited or no photosynthetic apparatus.

All algae have photosynthetic machinery ultimately derived from the cyanobacteria
Cyanobacteria is a phylum of Bacteria that obtain their energy through photosynthesis....
, and so produce oxygen
Oxygen is a chemical element with the chemical symbol O and atomic number 8....
 as a by-product of photosynthesis, unlike other photosynthetic bacteria such as purple
The purple sulfur bacteria are a group of Proteobacteria capable of photosynthesis, collectively referred to as purple bacte...
 and green sulfur bacteria
The green sulfur bacteria are a family of phototrophic bacteria....
.

Ecology

Algae are most prominent in bodies of water but are also common in terrestrial environments. However, terrestrial algae are usually rather inconspicuous and far more common in moist, tropical regions than dry ones, because algae lack vascular tissue
Vascular tissue is a complex tissue found in vascular plants....
s and other adaptations to live on land. Algae are also found in other situations, such as on snow
Watermelon snow is snow that is reddish or pink in color, with the slight scent of a fresh watermelon....
 and on exposed rocks in symbiosis
In some cases, the term symbiosis is used only if the association is obligatory and benefits both organisms....
 with a fungus as lichen
Lichens are symbiotic associations of a fungus with a photosynthetic partner that can produce food for the lichen from sunli...
.

The various sorts of algae play significant roles in aquatic ecology. Microscopic forms that live suspended in the water column provide the food base for most marine food chain
Food chains and food webs and/or food networks describe the feeding relationships between species in a biotic co...
s. In very high densities (so-called algal bloom
An algal bloom is a relatively rapid increase in the population of phytoplankton algae in an aquatic system....
s) these algae may discolor the water and outcompete, poison, or asphyxiate other life forms. Seaweeds grow mostly in shallow marine waters, however some have been recorded to a depth of 300 m.Some are used as human food or harvested for useful substances such as agar
Agar is an unbranched polysaccharide obtained from the cell walls of some species of red algae or seaweed....
, carrageenan
Carrageenans or carrageenins are a family of linear sulphated polysaccharides extracted from red seaweeds....
, or fertilizer.

Study of algae


The study of marine and freshwater algae is called phycology
Phycology, a subdiscipline of botany, is the scientific study of algae....
 or algology.

The US Algal Collection is represented by almost 300,000 accessioned and inventoried herbarium specimens.

Forms of algae

Most of the simpler algae are unicellular flagellate
Flagellates are cells with one or more whip-like organelles called flagella....
s or amoeboid
Amoeboids are cells that move or feed by means of temporary projections, called pseudopods ....
s, but colonial and non-motile forms have developed independently among several of the groups. Some of the more common organizational levels, more than one of which may occur in the life cycle
A life cycle is a period involving one generation of an organism through means of reproduction, whether through asexual repr...
 of a species, are
  • Colonial: small, regular groups of motile cells
  • Capsoid: individual non-motile cells embedded in mucilage
    Mucilage is a thick gluey substance produced by most plants and some microorganisms....
  • Coccoid: individual non-motile cells with cell walls
  • Palmelloid: non-motile cells embedded in mucilage
  • Filamentous: a string of non-motile cells connected together, sometimes branching
  • Parenchymatous: cells forming a thallus
    Thallus, from Latinized Greek θαλλος, meaning a green shoot or twig, is an ...
     with partial differentiation of tissues


In three lines even higher levels of organization have been reached, with full tissue differentiation. These are the brown algae
The brown algae or phaeophytes are a large group of multicellular algae, including many notable seaweeds....
 —some of which may reach 50 m in length—the red algae , and the green algae . The most complex forms are found among the green algae (see Charales
The Charales are an order of green alga-like plants believed to be the closest relatives of the green land plants....
 and Charophyta
The Charophyta are a division of green algae, including the closest relatives of the embryophyte plants....
), in a lineage that eventually led to the higher land plants. The point where these non-algal plants begin and algae stop is usually taken to be the presence of reproductive organs with protective cell layers, a characteristic not found in the other alga groups.

The first plants on earth evolved from shallow freshwater algae much like Chara some 400 million years ago. These probably had an isomorphic alternation of generations and were probably heterotrichous. Fossils of isolated land plant spores suggest land plants may have been around as long as 475 million years ago.

Algae and symbioses

Some species of algae form symbiotic relationships
In some cases, the term symbiosis is used only if the association is obligatory and benefits both organisms....
 with other organisms. In these symbioses, the algae supply photosynthates (organic substances) to the host organism providing protection to the algal cells. The host organism derives some or all of its energy requirements from the algae. Examples include
  • lichen
    Lichens are symbiotic associations of a fungus with a photosynthetic partner that can produce food for the lichen from sunli...
    s
    : a fungus is the host, usually with a green alga or a cyanobacterium as its symbiont. Both fungal and algal species found in lichens are capable of living independently, although habitat requirements may be greatly different from those of the lichen pair.
  • coral
    Corals are marine animals of the , which include sea anemones ....
    s
    : algae known as zooxanthella
    Zooxanthellae are golden-brown intracellular endosymbionts of various marine animals and protozoa, especially anthozoans....
    e are symbionts with coral
    Corals are marine animals of the , which include sea anemones ....
    s. Notable amongst these is the dinoflagellate Symbiodinium, found in many hard corals. The loss of Symbiodinium, or other zooxanthellae, from the host is known as coral bleaching
    ...
    .
  • sponge
    The sponges or poriferans are animals of the phylum Porifera....
    s
    : green algae live close to the surface of some sponges, for example, breadcrumb sponge (Halichondria panicea
    Halichondria panicea, commonly known as the breadcrumb sponge, is a species of marine demosponge belonging to the ...
    ). The alga is thus protected from predators; the sponge is provided with oxygen and sugars which can account for 50 to 80% of sponge growth in some species.

Life-cycle

Rhodophyta, Chlorophyta
The Chlorophyta sensu stricto or chlorophytes, comprises most of what are commonly called green algae and includes most ...
 and Heterokontophyta, the three main algal Phyla
Phylum is a taxon used in the scientific classification of life....
, have life-cycles which show tremendous variation with considerable complexity. In general there is an asexual phase where the seaweed's cells are diploid, a sexual phase where the cells are haploid followed by fusion of the male and female gametes. Asexual reproduction is advantageous in that it permits efficient population increases, but less variation is possible. Sexual reproduction allows more variation but is more costly because of the waste of gametes that fail to mate, among other things. Often there is no strict alternation between the sporophyte and gametophyte phases and also because there is often an asexual phase, which could include the fragmentation of the thallus.

See also

Conceptacle
In phycology, conceptacles are specialised cavities of seaweeds that contain the reproductive organs....

Numbers and distribution

In the British Isles the UK Biodiversity Steering Group Report estimated there to be 20,000 algal species in the UK, freshwater and marine, about 650 of these are seaweeds. Another checklist of freshwater algae reported only about 5000 species. It seems therefore that the 20,000 is an overestimate or an error (John, 2002 p.1).

The Smithsonian collection of algae has over 300,000 specimens.

World-wide it is thought that there are over 5,000 species of red algae, 1,500 — 2,000 of brown algae and 8,000 of green algae. In Australia it is estimated that there are over 1,300 species of red algae, 350 species of brown algae and approximately 2,000 species of green algae totalling 3,650 species of algae in Australia.

Around 400 species appear to be an average figure for the coastline of South Africa
Africa is one of the greatest sized continents of the Earth....
n west coast.

669 marine species have been described from California (U.S.A.).

642 entities are listed in the check-list of Britain and Ireland (Hardy and Guiry, 2006).

Britain and Ireland

  • Hardy, F.G. and Guiry, M.D. 2006. A Check-list and Atlas of the Seaweeds of Britain and Ireland. British Phycological Society, London. ISBN 3 906166 35 X
  • Cullinane, J.P. 1973. Phycology of the South Coast of Ireland. The Cork University Press, University College Cork.

Northumberland and Durham (England)

  • Hardy, F.G. and Aspinall, R.J. 1988. An Atlas of the Seaweeds of Northumberland and Durham. Northumberland Biological Records Centre. The Hancock Museum. The University Newcastle upon Tyne. Special publication: 3. ISBN 0 9509680 5 6

Northern Ireland

  • Morton, O. 1994. Marine Algae of Northern Ireland. Ulster Museum, Belfast. ISBN 0 900761 28 8

Republic of Ireland: County Donegal

  • Morton, O. The marine macroalgae of County Donegal, Ireland. Bull. Ir. biogeog. Soc. 27:3 - 164.

Isle of Man

  • Knight, M. and Park, M.W. 1931. Manx algae. An algal survey of the south end of the Isle of Man. L.M.B.C. Mem. Typ. Br. Mar. Pl. 390: 1 - 155.

Arctic

  • Kjellman, F.R. 1883. The algae of the Arctic Sea. K. sevenka. VetenskAkad. Handl. 20: 1 - 350.

Greenland

  • Lund, S. 1959. The Marine Algae of East Greenland. I. Taxonomical part. Meddr. Grønland 156: 1 - 247.

Faroe Islands

  • Borgesen, F. 1903. Marine Algae, pp.339 - 532. In, Warming, E. (Ed.), Botany of the Faröes Based Upon Danish Investigations. Part II. Copenhagen. [reprint 1970]

Atlantic(east coast)/Europe

  • Cabioc'h,J., Floc'h,J-Y., Le Toquin, A., Boudouresque, C-F., Meinesz, A. and Verlaque, M. 1992. Guide des algues des mers d'Europe. Delachaux et Niestlé, Switzerland.
  • Gayral, P. 1958 Algues de la Côte Atlantique Marocaine. Rabat.
  • Gayral, P. 1966. Algues des Côtes Françaises. Paris.

Canary Islands.

  • Borgesen,F. 1925. Marine algae from the Canary Islands, especially from Tenerife and Gran Canaria. I. Chlorophyceae. Biol. Meddr 5: 1 - 113.


  • Borgesen,F. 1926. Marine algae from the Canary Islands especially from Tenerife and Gran Canaria. II. Phaeophyceae. Biol. Meddr 6: 1 - 112.


  • Borgesen,F. 1927. Marine algae from the Canary Islands. III. Rhodophyceae. Part I, Bangiales and Nemalionales. Biol. Meddr 6: 1 - 97.


  • Borgesen,F. 1929. Marine algae from the Canary Islands. III Rhodophyceae. Part II. Cryptonemiales, Gigartinales and Rhodymeniales. Biol. Meddr 8: 1 - 97.


  • Borgesen,F. 1930. Marine algae from the Canary Islands. III Rhodophyceae. Part II. Cryptonemiales, Gigartinales and Rhodymeniales. Biol. Meddr 9: 1 - 159.

North America

  • Taylor, W.R. 1957. Marine Algae of the Northeastern Coast of North America. University of Michigan Press, Ann Arbor.


  • Abbott, I.A. and Hollenberg, G.J. 1976. Marine Algae of California. Stanford University Press, California.


  • Wehr, J.D. and Sheath, R.G. 2003. Freshwater Algae of North America: Ecology and Classification. Academic Press, USA.

South Africa

  • Stegenga, H. Bolton, J.J. and Anderson, R.J. 1997. Seaweeds of the South African West Coast. Bolus Herbarium Number 18, Publication jointly financed by the Fourcade Bequest and the Research Committee of the University of Cape Town and the Foundation for Research Development.

New Zealand

  • Lindauer, V.W., Chapman, V.J. and Aiken, M. 1961. The Marine Algae of New Zealand. Part II. Phaeophyta. Nova Hedwigia 3: 129 - 350.
  • Chapman, V.J. 1969. The Marine Algae of New Zealand. Part III issues 1. Lehre: J.Cramer, 1 - 113.
  • Chapman, V.J. and Dromgoole, F.I. 1970. The Marine Algae of New Zealand. Part III issues 2. Lehre: J.Cramer, 115 - 154.
  • Chapman, V.J. and Parkinson, P.G. 1974 The Marine Algae of New Zealand. Part III issues 3. Lehre: J.Cramer,155 - 278.
  • Chapman, V.J. 1979 The Marine Algae of New Zealand. Part III issues 4. Lehre: J.Cramer, 279 - 420.

Uses of algae

Fertilizer

For centuries seaweed has been used as a fertilizer; Orwell writing in the 16th century referring to drift weed in South Wales: "This kind of ore they often gather and lay in heaps where it heats and rots, and will have a strong and loathsome smell; when being so rotten they cast it on the land, as they do their muck, and thereof springeth good corn, especially barley" and "After spring tides or great rigs of the sea, they fetch it in sacks on horse brackets, and carry the same three, four, or five miles, and cast it on the lande, which doth very much better the ground for corn and grass" (Chapman p.35).

Algae are used by humans in many ways. They are used as fertilizers, soil conditioners and are a source of livestock feed. Because many species are aquatic and microscopic, they are cultured in clear tanks or ponds and either harvested or used to treat effluents pumped through the ponds. Algaculture
Algaculture is a form of aquaculture involving the farming of species of algae....
 on a large scale is an important type of aquaculture
Aquaculture is the cultivation of the natural produce of water ....
 in some places.

Maerl
Maerl is a collective name for two or three species of red algae in the Corallinacease....
 is commonly used as a soil conditioner, it is dredged from the sea floor and crushed to form a powder. It is still harvested around the coasts of Brittany
Brittany is a former independent kingdom and duchy, then province of France and, at the same time, one of the six Celtic Na...
 in France
France, officially the French Republic, is a country whose metropolitan territory is located in Western Europe and whi...
 and off Falmouth, Cornwall
Falmouth is a seaport on the River Fal on the south coast of Cornwall, England, UK....
 (also extensively in western Ireland) and is a popular fertilizer in these days of organic gardening investigated Falmouth maerl and found that L. corallioides predominated down to 6 m and P. calcareum from 6-10 m (Blunden et al., 1981).

Chemical analysis of maerl showed that it contained 32.1% CaCO3 and 3.1% MgCO3 (dry weight).

Energy source

  • Algae can be used to make biodiesel
    Biodiesel refers to a diesel-equivalent, processed fuel derived from biological sources....
     (see algaculture
    Algaculture is a form of aquaculture involving the farming of species of algae....
    ), bioethanol and biobutanol and by some estimates can produce vastly superior amounts of vegetable oil, compared to terrestrial crops grown for the same purpose.
  • Algae can be grown to produce biohydrogen
    Biohydrogen is hydrogen produced via biological processes or from biomass....
    . In 1939 a German researcher named Hans Gaffron, while working at the University of Chicago, observed that the algae he was studying, Chlamydomonas reinhardtii
    Chlamydomonas reinhardtii is a motile single celled green alga about 10 micrometres in diameter that swims with two flag...
    (a green-alga), would sometimes switch from the production of oxygen to the production of hydrogen. Gaffron never discovered the cause for this change and for many years other scientists failed to repeat his findings. In the late 1990s professor Anastasios Melis, a researcher at the University of California at Berkeley, discovered that if the algae culture medium is deprived of sulfur it will switch from the production of oxygen (normal photosynthesis), to the production of hydrogen. He found that the enzyme
    Enzymes are proteins that accelerate, or catalyze, chemical reactions....
     responsible for this reaction is hydrogenase
    A hydrogenase is an enzyme that catalyses the reversible oxidation of molecular hydrogen....
    , but that the hydrogenase lost this function in the presence of oxygen. Melis found that depleting the amount of sulfur available to the algae interrupted its internal oxygen flow, allowing the hydrogenase an environment in which it can react, causing the algae to produce hydrogen. Chlamydomonas moeweesi is also a good strain for the production of hydrogen. Scientists at the U.S. Department of Energy’s Argonne National Laboratory are currently trying to find a way to take the part of the hydrogenase enzyme that creates the hydrogen gas and introduce it into the photosynthesis process. The result would be a large amount of hydrogen gas, possibly on par with the amount of oxygen created.
  • Algae can be grown to produce biomass
    In energy production and industry, biomass refers to living and recently living biological material which can be used as fue...
    , which can be burned to produce heat and electricity.
  • Algae can be used in oil production which could replace the petrol and other gas products in the near future.

Pollution control

  • Algae are used in wastewater treatment facilities, reducing the need for greater amounts of toxic chemicals than are already used.
  • Algae can be used to capture fertilizers in runoff from farms. When subsequently harvested, the enriched algae itself can be used as fertilizer.
  • Algae Bioreactors are used by some powerplants to reduce CO2 emissions. The CO2 can be pumped into a pond, or some kind of tank, on which the algae feed. Alternatively, the bioreactor can be installed directly on top of a smokestack. This technology has been pioneered by Massachusetts-based GreenFuelTechnologies.

Stabilizing substances

Chondrus crispus, (probably confused with Mastocarpus stellatus
Mastocarpus stellatus, also called Clúimhín Chait, Carragheen, or Carrageen Moss, is closely related to Irish Moss, or Cho...
, common name: Irish moss), is also used as "carrageen". The name carrageenan comes from the Irish Gaelic for Chondrus crispus. It is an excellent stabiliser in milk products - it reacts with the milk protein caesin, other products include: petfoods, toothpaste, ice-creams and lotions etc. Alginates in creams and lotions are absorbable through the skin.

Nutrition

Seaweeds are an important source of food, especially in Asia; They are excellent sources of many vitamins including: A, B1
Thiamine or thiamin, also known as vitamin B1, is a colorless compound with chemical formula C12H17N4OS....
, B2
Riboflavin , also known as vitamin B2 or vitamin G, is an easily absorbed, water-soluble micronutrient with a ke...
, B6
Vitamin B6 is a water-soluble vitamin....
, niacin
Niacin, also known as nicotinic acid or vitamin B3, is a water-soluble vitamin whose derivatives such as NADH, N...
 and C
Vitamin C is a water-soluble nutrient and vitamin essential for life and for maintaining optimal health....
. They are rich in iodine
Iodine , is a chemical element in the periodic table that has the symbol I and atomic number 53....
, potassium
Potassium is a chemical element. It has the symbol K and atomic number 19....
, iron
Iron is a chemical element with the symbol Fe and atomic number 26....
, magnesium
Magnesium is the chemical element in the periodic table that has the symbol Mg and atomic number 12 and an atomic mass...
 and calcium
Calcium is the chemical element in the periodic table that has the symbol Ca and atomic number 20....
.

Algae is commercially cultivated as a nutritional supplement. One of the most popular microalgal species is Spirulina (Arthrospira platensis), which is a Cyanobacteria
Cyanobacteria is a phylum of Bacteria that obtain their energy through photosynthesis....
 (known as blue-green algae), and has been hailed by some as a superfood. Other algal species cultivated for their nutritional value include; Chlorella
Chlorella is a genus of single-celled green algae, belonging to the phylum Chlorophyta....
 (a green algae), and Dunaliella
In taxonomy, Dunaliella is a genus of algae, specifically of the Dunaliellaceae....
 (Dunaliella salina), which is high in beta-carotene
Beta-carotene is an organic compound and a terpenoid....
 and is used in vitamin C supplements.

In China at least 70 species of algae are eaten as is the Chinese "vegetable" known as fat choy (which is actually a cyanobacterium). Roughly 20 species of algae are used in everyday cooking in Japan.

Certain species are edible; the best known, especially in Ireland is Palmaria palmata (Linnaeus) O. Kuntze, also known as Rhodymenia palmata (Linnaeus) Kuntze, common name: dulse
Palmaria palmata KuntzeDulse, also called dillisk, dulse or creathnach, is a red alga that g...
). This is a red alga which is dried and may be bought in the shops in Ireland
Ireland is the third largest island in Europe....
. It is eaten raw, fresh or dried, or cooked like spinach. Similarly, Durvillaea antarctica is eaten in Chile, common name: cochayuyo.

Porphyra
Porphyra is a genus of red algae....
(common name: purple laver
Laver is an edible seaweed that has high content of mineral salts, particularly iodine and iron....
), is also collected and used in a variety of ways (e.g. "laver bread" in the British Isles). In Ireland it is collected and made into a jelly by stewing or boiling. Preparation also involves frying with fat or converting to a pinkish jelly by heating the fronds in a saucepan with a little water and beating with a fork. It is also collected and used by people parts of Asia, specifically China, Korea|gim]]) and Japan and along most of the coast from California
California is a state spanning the southern half of the west coast of the contiguous United States....
 to British Columbia
British Columbia, often referred to as B.C. or BC , is the westernmost of Canada's provinces and is famed for it...
. The Hawaiians and the Maoris of New Zealand
New Zealand is a country in the south-western Pacific Ocean consisting of two large islands and many much smaller islands, m...
 also use it.

One particular use is in "instant" puddings, sauces and creams. Ulva lactuca (common name: sea lettuce), is used locally in Scotland where it is added to soups or used in salads. Alaria esculenta (common name: badderlocks or dabberlocks), is used either fresh or cooked, in Greenland
Greenland is a self-governed Danish territory....
, Iceland
Iceland, officially the Republic of Iceland is a volcanic island nation in the northern Atlantic Ocean between Greenl...
, Scotland
Scotland is a nation in northwest Europe and one of the constituent countries of the United Kingdom....
 and Ireland.

The oil from some algae have high levels of unsaturated fatty acids. Arachidonic acid
Arachidonic acid is an omega-6 fatty acid with the chemical formula C20H32O2....
 (a polyunsaturated fatty acid), is very high in Parietochloris incisa, (a green alga) where it reaches up to 47% of the triglyceride pool (Bigogno C et al. Phytochemistry 2002, 60, 497).

It is a known fact that fish oil contains the omega-3 fatty acids docosahexaenoic acid, commonly known as DHA and eicosapentaenoic acid, or EPA; but The Martek Biosciences Corporation who discovered the source of DHA to be from algae manufactures DHA from algae, which is where fish get their DHA, explains J. Casey Lippmeier, Martek's senior scientist.

The algae are eaten by smaller marine life such as copepods, "and those are eaten by slightly larger fish," says Lippmeier. The DHA gets passed along the food chain, all the way up to the biggest fish, but the original source is the algae.

You can refer to the following npr.org link for an article on algae and omega-3 fatty acids; http://www.npr.org/templates/story/story.php?storyId=15823852.

Other uses

There are also commercial uses of algae as agar.

The natural pigment
A pigment is a material that changes the color of light it reflects as the result of selective color absorption....
s produced by algae can be used as an alternative to chemical dyes and coloring agents. Many of the paper products used today are not recyclable because of the chemical inks that they use, paper recyclers have found that inks made from algae are much easier to break down. There is also much interest in the food industry into replacing the coloring agents that are currently used with coloring derived from algal pigments. Algae can be used to make pharmaceuticalsSewage can be treated with algae as well
Some cosmetics can come from microalgae as well.
In Israel
Israel , officially the State of Israel, is a country in Western Asia on the southeastern edge of the Mediterranean Se...
, a species of green algae is grown in water tanks, then exposed to direct sunlight and heat which causes it to become bright red in color. It is then harvested and used as a natural pigment for foods such as Salmon.

Alginates

Between 100,000 and 170,000 wet tons of Macrocystis
Macrocystis is a genus of kelp....
are harvested annually in California
California is a state spanning the southern half of the west coast of the contiguous United States....
 for alginate extraction and abalone feed.

Collecting and preserving specimens

Seaweed specimens can be collected and preserved for research. Such preserved specimens will keep for two or three hundred years. Those of Carl von Linné (1707 — 1778) are still available for reference, and are used. Specimens may be collected from the shore; those below low tide must be collected by diving or dredging. The whole algal specimen should be collected, that is the holdfast
A holdfast is a rootlike plant structure that anchors a seaweed, or other multicellular organism....
, stipe and lamina. Specimens of algae reproducing will be the more useful for identification and research. When collected the details of the location and site should be noted. They can then be preserved pressed on paper or in a preserving liquid such as alcohol or solution of 5 per cent formalin/seawater. However, formalin is reported to be carcinogenic.

Ecology

Biological Exposure Scale

The ecology of the shores of the British Isles, including a discussion of the different shores from sheltered to exposed along with an exposure scale, is given by Lewis (1964). An exposure scale of five stages is given:- Very Exposed Shores; Exposed Shores; Semi-exposed Shores; Sheltered Shores and Very Sheltered Shores. Factors indicating the differences between these exposure scales are detailed. Very Exposed Shores have a wide Verrucaria zone entirely above the upper tide level, a Porphyra zone above the barnacle level and Lichina pygmaea is locally abundant. The eulittoral zone is dominated by barnacles and limpets with a coralline belt in the very low littoral along with other Rhodophyta and Alaria
Brown algae, in the Kingdom Chromista, Order Laminariales and Family Alariaceae there are up to 14 species of the Genus Alaria...
in the upper sublittoral. Exposed shores show a Verrucaria belt mainly above the high tide, with Porphyra and Lichina pygmaea. The mid shore is dominated by barnacles, limpets and some Fucus. Some Rhodophyta. Himanthalia and some Rhodophyta such as Mastocarpus and Corallina are found in the low littorral with Himanthalia, Alaria
Brown algae, in the Kingdom Chromista, Order Laminariales and Family Alariaceae there are up to 14 species of the Genus Alaria...
and Laminaria
Laminaria is a genus of kelp, containing over 20 species....
 digitata
dominant in the upper sublittoral. The semi-exposed shores show a Verrucaria belt just above high tide with clear Pelvetia in the upper-littoral and Fucus serratus in the lower-littoral. Limpets, barnacles and short Fucus vesiculosus midshore. Fucus serratus with Rhodophyta, (Laurencia, Mastocarpus stellatus
Mastocarpus stellatus, also called Clúimhín Chait, Carragheen, or Carrageen Moss, is closely related to Irish Moss, or Cho...
, Rhodymenia and Lomentaria). Laminaria and Saccorhiza polyschides and small algae common in the sublittoral. The sheltered shores show a narrow Verrucaria zone at high water and a full sequence of fucoids: Pelvetia, Fucus spiralis, Fucus vesiculosus, Fucus serratus, Ascophyllum nodosum. Laminaria digitata is dominant the upper sublittoral. The very sheltered shores show a very narrow zone of Verrucaria, the dominance of the littoral by a full sequence of the fucoids and Ascophyllum covering the rocks. Laminaria saccharina, Halidrys, Chondrus and or Furcellaria.

Common names

  • Alaria sculenta Dabberlocks; Edible kelp


  • Ascophyllum nodosum Knotted wrack


  • Chondrus crispus Carragheen; Irish moss


  • Chorda filum Sea lace


  • Colpomena peregrina Oyster thief


  • Fucus
    Fucus is a brown alga a genus of seaweed that lives in the intertidal zones of rocky shores....
    Wrack


  • Fucus ceranoides Horned wrack


  • Fucus serratus Toothwrack


  • Fucus vesiculosus Bladderwrack


  • Fucus spirals Spiral wrack


  • Haldrys siliquosa Sea oak


  • Halurus euisetifolius Seatail


  • Himanthalia elongata Sea thong; Thong-weed


  • Laminaria digitata Tangle; Oarweed


  • Laminaria hyperborea Curvie


  • Laminaria saccharina Sea belt; Sugar Kelp; Sugarwrack


  • Laurencia pinnatifida Pepper dulse


  • Padin pavonia Peacocks


  • Palmaria palmata Dulse




  • Plocamium vulgare Cockscomb


  • Polyides caprinus Goat tang


  • Polysiphonia elongata Lobster horns


  • Porphyra umbilicalis Purple laver; Laver




  • Ulva lactuca
    Ulva lactuca Linnaeus, a Green alga in the Division Chlorophyta, is the type species of the genus Ulva; also known a...
    Sea lettuce

Examples

  • Atractophora hypnoides P.L.Crouan and H.M.Crouan
  • Ascophyllum nodosum
  • Charales
    The Charales are an order of green alga-like plants believed to be the closest relatives of the green land plants....
  • Codium
    Codium is a genus of seaweed in the Chlorophyta of the Order Bryopsidales....
  • Fucus
    Fucus is a brown alga a genus of seaweed that lives in the intertidal zones of rocky shores....
  • Ulva lactuca
    Ulva lactuca Linnaeus, a Green alga in the Division Chlorophyta, is the type species of the genus Ulva; also known a...
  • Laminaria
    Laminaria is a genus of kelp, containing over 20 species....
  • Lemanea
    Lemanea is the generic name for an alga of which there are two species in the British Isles:-...
  • Macrocystis
    Macrocystis is a genus of kelp....
  • Mastocarpus stellatus
    Mastocarpus stellatus, also called Clúimhín Chait, Carragheen, or Carrageen Moss, is closely related to Irish Moss, or Cho...
  • Pelvetia canaliculata
    Pelvetia canaliculata Dcne. et Thur....
  • Palmaria palmata
  • Porphyra
    Porphyra is a genus of red algae....
  • Postelsia palmaeformis

See also

  • Algaculture
    Algaculture is a form of aquaculture involving the farming of species of algae....
  • Biological hydrogen production (Algae)
  • Brown Algae
    The brown algae or phaeophytes are a large group of multicellular algae, including many notable seaweeds....
  • Chlorophyta
    The Chlorophyta sensu stricto or chlorophytes, comprises most of what are commonly called green algae and includes most ...
  • Coccolithophore
    Coccolithophores are single-celled algae, or phytoplankton, belonging to the haptophytes....
  • Conceptacle
    In phycology, conceptacles are specialised cavities of seaweeds that contain the reproductive organs....
  • Coralline algae
    Coralline algae are red algae in the Family Corallinaceae of the order Corallinales characterized by a thallus that is hard ...
  • Cyanobacteria
    Cyanobacteria is a phylum of Bacteria that obtain their energy through photosynthesis....
  • Diatom
    Diatoms are a major group of eukaryotic algae, and are one of the most common types of phytoplankton....
  • Golden Algae
    The golden algae or chrysophytes are a large group of heterokont algae, found mostly in freshwater....
  • Green Algae
    The Green Algae are the large group of algae from which the embryophytes emerged....
  • Hydrology transport model
  • Important publications in phycology
  • Kelp
    Kelp are large seaweeds, belonging to the brown algae and classified in the order Laminariales....
  • Laminaria
    Laminaria is a genus of kelp, containing over 20 species....
  • Nori
    Nori , known in Chinese as haidi and in Korean as kim or gim , is the Japanese name for various edible se...
  • Red Algae
    The red algae?f??t?/, ancient Greek: rhodos phytos = red plant) are a large group of mostly multicellular, marine algae, inc...
  • Yellow-Green Algae
    Yellow-green algae or xanthophytes are an important group of heterokont algae....
  • Marimo
    Marimo, also known as Cladophora ball, Lake ball, or Moss Balls in English, is a species of filamentous gr...
  • History of phycology
    Phycology is the study of algae and history is the study of the past human activities....


Identification

  • Abbott, I.A. and Hollenberg, G.J. 1976. Marine Algae of California. Stanford University Press, California. ISBN 0-8047-0867-3
  • Brodie, J.A. and Irvine, L.M. 2003. Seaweeds of the British Isles. Volume 1 Part 3B. The Natural History Museum, London. ISBN 1 898298 87 4
  • Burrows, E.M. 1991. Seaweeds of the British Isles. Volume 2. British Museum (Natural History), London. ISBN 0-565-00981-8
  • Christensen, T. 1987. Seaweeds of the British Isles. Tribophyceae. Volume 4. British Museum (Natural History), London. ISBN 0-565-00980-X
  • Dixon, P.S. and Irvine, L.M. 1977. Seaweeds of the British Isles. Volume 1. Part 1. Introduction, Nemaliales, Gigartinales. British Museum (Natural History), London. ISBN 0 565 00781 5
  • Greeson, Phillip E. 1982. An annotated key to the identification of commonly occurring and dominant genera of Algae observed in the Phytoplankton of the United States [Geological Survey Water-Supply Paper 2079]. Washington, D.C.: United States Government Printing Office.
  • Irvine, L.M. 1983. Seaweeds of the British Isles. Volume 1, Part 2A. British Museum (Natural History), London. ISBN 0-565-00871-4
  • Irvine, L.M. and Chamberlain, Y.M. 1994. Seaweeds of the British Isles. Volume 1 Part 2B. The Natural History Museum, London. ISBN 0 11 310016 7
  • Fletcher, R.L. 1987. Seaweeds of the British Isles. Volume 3 Part 1. British Museum (Natural History), London. ISBN 0-565-00992-3
  • John, D.M., Whitton, B.A. and Brook, J.A. (Eds.) 2002. The Freshwater Algal Flora of the British Isles. Cambridge University Press, UK. ISBN 0 521 77051 3
  • Stegenga, H., Bolton, J.J. and Anderson, R.J.1997. Seaweeds of the South African west coast. Boltus Herbarium, University of Cape Town. ISBN 0-7992-1793-x
  • Taylor, W.R. 1957. Marine algae of the north-eastern coasts of North America. Revised edition. University of Michigan Press. Ann Arbor.

General

  • Chapman, V.J. 1950.p.36. Seaweeds and their Uses. Methuen & Co. Ltd., London.
  • Guiry, M.D. and Blunden, G. (Eds) 1991. Seaweed Resources in Europe: Uses and Potential. John Wiley & Sons. ISBN 0-471-92947-6
  • Lembi, C.A. and Waaland, J.R. (Eds.) 1988. Algae and Human Affairs. Cambridge University Press, Cambridge. ISBN 0-521-32115-8