Algae constitute a polyphyletic group since they do not include a common ancestor, and although their
plastids seem to have a single origin, from cyanobacteria, they were acquired in different ways. Green algae are examples of algae that have primary
chloroplasts derived from
brown algae are examples of algae with secondary chloroplasts derived from an
endosymbioticred alga. Algae exhibit a wide range of reproductive strategies, from simple
asexual cell division to complex forms of
Because of the wide range of types of algae, they have increasing different industrial and traditional applications in human society. Traditional
seaweed farming practices have existed for thousands of years and have strong traditions in East Asia food cultures. More modern
algaculture applications extend the
food traditions for other applications include cattle feed, using algae for
bioremediation or pollution control, transforming sunlight into
algae fuels or other chemicals used in industrial processes, and in medical and scientific applications. A 2020 review found that these applications of algae could play an important role in
carbon sequestration in order to
mitigate climate change while providing valuable value-add products for global economies.
Etymology and study
The singular alga is the Latin word for 'seaweed' and retains that meaning in English. The
etymology is obscure. Although some speculate that it is related to Latin algēre, 'be cold', no reason is known to associate seaweed with temperature. A more likely source is alliga, 'binding, entwining'.
Ancient Greek word for 'seaweed' was φῦκος (phŷkos), which could mean either the seaweed (probably red algae) or a red dye derived from it. The Latinization, fūcus, meant primarily the cosmetic rouge. The etymology is uncertain, but a strong candidate has long been some word related to the
Biblicalפוך (pūk), 'paint' (if not that word itself), a cosmetic eye-shadow used by the
ancient Egyptians and other inhabitants of the eastern Mediterranean. It could be any color: black, red, green, or blue.
Accordingly, the modern study of marine and freshwater algae is called either
phycology or algology, depending on whether the Greek or Latin root is used. The name fucus appears in a number of
The committee on the International Code of Botanical Nomenclature has recommended certain suffixes for use in the classification of algae. These are -phyta for division, -phyceae for class, -phycideae for subclass, -ales for order, -inales for suborder, -aceae for family, -oidease for subfamily, a Greek-based name for genus, and a Latin-based name for species.
Algal characteristics basic to primary classification
The primary classification of algae is based on certain morphological features. The chief among these are (a) pigment constitution of the cell, (b) chemical nature of stored food materials, (c) kind, number, point of insertion and relative length of the flagella on the motile cell, (d) chemical composition of cell wall and (e) presence or absence of a definitely organized nucleus in the cell or any other significant details of cell structure.
History of classification of algae
Carolus Linnaeus (1754) included algae along with lichens in his 25th class Cryptogamia, he did not elaborate further on the classification of algae.
Jean Pierre Étienne Vaucher (1803) was perhaps the first to propose a system of classification of algae, and he recognized three groups, Conferves, Ulves, and Tremelles. While
Johann Heinrich Friedrich Link (1820) classified algae on the basis of the colour of the pigment and structure,
William Henry Harvey (1836) proposed a system of classification on the basis of the habitat and the pigment.
J. G. Agardh (1849–1898) divided algae into six orders: Diatomaceae, Nostochineae, Confervoideae, Ulvaceae, Floriadeae and Fucoideae. Around 1880, algae along with fungi were grouped under Thallophyta, a division created by Eichler (1836). Encouraged by this,
Adolf Engler and
Karl A. E. Prantl (1912) proposed a revised scheme of classification of algae and included fungi in algae as they were of opinion that fungi have been derived from algae. The scheme proposed by Engler and Prantl is summarised as follows:
The algae contain
chloroplasts that are similar in structure to cyanobacteria. Chloroplasts contain circular
DNA like that in cyanobacteria and are interpreted as representing reduced endosymbiotic cyanobacteria. However, the exact origin of the chloroplasts is different among separate lineages of algae, reflecting their acquisition during different endosymbiotic events. The table below describes the composition of the three major groups of algae. Their lineage relationships are shown in the figure in the upper right. Many of these groups contain some members that are no longer photosynthetic. Some retain plastids, but not chloroplasts, while others have lost plastids entirely.
These algae have "primary"
chloroplasts, i.e. the chloroplasts are surrounded by two membranes and probably developed through a single endosymbiotic event. The chloroplasts of red algae have
chlorophyllsa and c (often), and
phycobilins, while those of green algae have chloroplasts with chlorophyll a and b without phycobilins. Land plants are pigmented similarly to green algae and probably developed from them, thus the
Chlorophyta is a sister taxon to the plants; sometimes the Chlorophyta, the
Charophyta, and land plants are grouped together as the
These groups have green chloroplasts containing chlorophylls a and b. Their chloroplasts are surrounded by four and three membranes, respectively, and were probably retained from ingested green algae.
Euglenids, which belong to the phylum
Euglenozoa, live primarily in fresh water and have chloroplasts with only three membranes. The endosymbiotic green algae may have been acquired through
myzocytosis rather than
These groups have chloroplasts containing chlorophylls a and c, and phycobilins. The shape can vary; they may be of discoid, plate-like, reticulate, cup-shaped, spiral, or ribbon shaped. They have one or more pyrenoids to preserve protein and starch. The latter chlorophyll type is not known from any prokaryotes or primary chloroplasts, but genetic similarities with red algae suggest a relationship there.
In the first three of these groups (Chromista), the chloroplast has four membranes, retaining a
cryptomonads, and they likely share a common pigmented ancestor, although other evidence casts doubt on whether the
cryptomonads are in fact more closely related to each other than to other groups.
The typical dinoflagellate chloroplast has three membranes, but considerable diversity exists in chloroplasts within the group, and a number of endosymbiotic events apparently occurred. The
Apicomplexa, a group of closely related parasites, also have plastids called
apicoplasts, which are not photosynthetic, but appear to have a common origin with
title page of
Gmelin'sHistoria Fucorum, dated 1768
Samuel Gottlieb Gmelin (1744–1774) published the Historia Fucorum, the first work dedicated to marine algae and the first book on
marine biology to use the then new binomial nomenclature of Linnaeus. It included elaborate illustrations of seaweed and marine algae on folded leaves.
W. H. Harvey (1811–1866) and
Lamouroux (1813) were the first to divide macroscopic algae into four divisions based on their pigmentation. This is the first use of a biochemical criterion in plant systematics. Harvey's four divisions are: red algae (Rhodospermae), brown algae (Melanospermae), green algae (Chlorospermae), and Diatomaceae.
At this time, microscopic algae were discovered and reported by a different group of workers (e.g.,
O. F. Müller and
Ehrenberg) studying the
Infusoria (microscopic organisms). Unlike
macroalgae, which were clearly viewed as plants,
microalgae were frequently considered animals because they are often motile. Even the nonmotile (coccoid) microalgae were sometimes merely seen as stages of the lifecycle of plants, macroalgae, or animals.
Although used as a taxonomic category in some pre-Darwinian classifications, e.g., Linnaeus (1753), de Jussieu (1789), Horaninow (1843), Agassiz (1859), Wilson & Cassin (1864), in further classifications, the "algae" are seen as an artificial, polyphyletic group.
With the abandonment of plant-animal dichotomous classification, most groups of algae (sometimes all) were included in
Protista, later also abandoned in favour of
Eukaryota. However, as a legacy of the older plant life scheme, some groups that were also treated as
protozoans in the past still have duplicated classifications (see
The first land plants probably evolved from shallow freshwater charophyte algae much like Chara almost 500 million years ago. These probably had an isomorphic
alternation of generations and were probably filamentous. Fossils of isolated land plant spores suggest land plants may have been around as long as 475 million years ago.
kelp forest exhibit at the Monterey Bay Aquarium: A three-dimensional, multicellular thallus
Most of the simpler algae are
amoeboids, but colonial and nonmotile 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
lifecycle of a species, are
Capsoid: individual non-motile cells embedded in
Coccoid: individual non-motile cells with cell walls
Palmelloid: nonmotile cells embedded in mucilage
Filamentous: a string of connected nonmotile cells, sometimes branching
Parenchymatous: cells forming a thallus 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,—some of which may reach 50 m in length (
kelps)—the red algae, and the green algae. The most complex forms are found among the charophyte algae (see
Charophyta), in a lineage that eventually led to the higher land plants. The innovation that defines these nonalgal plants is the presence of female reproductive organs with protective cell layers that protect the zygote and developing embryo. Hence, the land plants are referred to as the
The term algal turf is commonly used but poorly defined. Algal turfs are thick, carpet-like beds of seaweed that retain sediment and compete with foundation species like
kelps, and they are usually less than 15 cm tall. Such a turf may consist of one or more species, and will generally cover an area in the order of a square metre or more. Some common characteristics are listed:
Algae that form aggregations that have been described as turfs include diatoms, cyanobacteria, chlorophytes, phaeophytes and rhodophytes. Turfs are often composed of numerous species at a wide range of spatial scales, but monospecific turfs are frequently reported.
Turfs can be morphologically highly variable over geographic scales and even within species on local scales and can be difficult to identify in terms of the constituent species.
Turfs have been defined as short algae, but this has been used to describe height ranges from less than 0.5 cm to more than 10 cm. In some regions, the descriptions approached heights which might be described as canopies (20 to 30 cm).
This section needs expansion. You can help by
adding to it. (February 2021)
Some species of algae form
symbiotic relationships 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 are:
Lichens are defined by the
International Association for Lichenology to be "an association of a fungus and a photosynthetic
symbiont resulting in a stable vegetative body having a specific structure". The fungi, or mycobionts, are mainly from the
Ascomycota with a few from the
Basidiomycota. In nature, they do not occur separate from lichens. It is unknown when they began to associate. One mycobiont associates with the same phycobiont species, rarely two, from the green algae, except that alternatively, the mycobiont may associate with a species of cyanobacteria (hence "photobiont" is the more accurate term). A photobiont may be associated with many different mycobionts or may live independently; accordingly, lichens are named and classified as fungal species. The association is termed a morphogenesis because the lichen has a form and capabilities not possessed by the symbiont species alone (they can be experimentally isolated). The photobiont possibly triggers otherwise latent genes in the mycobiont.
Trentepohlia is an example of a common green alga genus worldwide that can grow on its own or be lichenised. Lichen thus share some of the habitat and often similar appearance with specialized species of algae (aerophytes) growing on exposed surfaces such as tree trunks and rocks and sometimes discoloring them.
Endosymbiontic green algae live close to the surface of some sponges, for example, breadcrumb sponges (Halichondria panicea). 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.
Heterokontophyta, the three main algal
divisions, have life cycles which show considerable variation and complexity. In general, an asexual phase exists 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 permits efficient population increases, but less variation is possible. Commonly, in sexual reproduction of unicellular and colonial algae, two specialized, sexually compatible, haploid gametes make physical contact and fuse to form a
zygote. To ensure a successful mating, the development and release of gametes is highly synchronized and regulated; pheromones may play a key role in these processes. Sexual reproduction allows for more variation and provides the benefit of efficient recombinational repair of DNA damages during
meiosis, a key stage of the sexual cycle. However, sexual reproduction is more costly than asexual reproduction. Meiosis has been shown to occur in many different species of algae.
The Algal Collection of the US National Herbarium (located in the
National Museum of Natural History) consists of approximately 320,500 dried specimens, which, although not exhaustive (no exhaustive collection exists), gives an idea of the order of magnitude of the number of algal species (that number remains unknown). Estimates vary widely. For example, according to one standard textbook, in the
British Isles the UK Biodiversity Steering Group Report estimated there to be 20,000 algal species in the UK. Another checklist reports only about 5,000 species. Regarding the difference of about 15,000 species, the text concludes: "It will require many detailed field surveys before it is possible to provide a reliable estimate of the total number of species ..."
Regional and group estimates have been made, as well:
400 seaweed species for the western coastline of South Africa, and 212 species from the coast of KwaZulu-Natal. Some of these are duplicates, as the range extends across both coasts, and the total recorded is probably about 500 species. Most of these are listed in
List of seaweeds of South Africa. These exclude
phytoplankton and crustose corallines.
and so on, but lacking any scientific basis or reliable sources, these numbers have no more credibility than the British ones mentioned above. Most estimates also omit microscopic algae, such as phytoplankton.
The most recent estimate suggests 72,500 algal species worldwide.
The distribution of algal species has been fairly well studied since the founding of
phytogeography in the mid-19th century. Algae spread mainly by the dispersal of
spores analogously to the dispersal of
spores. This dispersal can be accomplished by air, water, or other organisms. Due to this, spores can be found in a variety of environments: fresh and marine waters, air, soil, and in or on other organisms. Whether a spore is to grow into an organism depends on the combination of the species and the environmental conditions where the spore lands.
The spores of freshwater algae are dispersed mainly by running water and wind, as well as by living carriers. However, not all bodies of water can carry all species of algae, as the chemical composition of certain water bodies limits the algae that can survive within them. Marine spores are often spread by ocean currents. Ocean water presents many vastly different habitats based on temperature and nutrient availability, resulting in phytogeographic zones, regions, and provinces.
To some degree, the distribution of algae is subject to floristic discontinuities caused by geographical features, such as
Antarctica, long distances of ocean or general land masses. It is, therefore, possible to identify species occurring by locality, such as "
Pacific algae" or "
North Sea algae". When they occur out of their localities, hypothesizing a transport mechanism is usually possible, such as the hulls of ships. For example, Ulva reticulata and U. fasciata travelled from the mainland to
Hawaii in this manner.
Mapping is possible for select species only: "there are many valid examples of confined distribution patterns." For example, Clathromorphum is an arctic genus and is not mapped far south of there. However, scientists regard the overall data as insufficient due to the "difficulties of undertaking such studies."
Algae are prominent in bodies of water, common in terrestrial environments, and are found in unusual environments, such as on
ice. Seaweeds grow mostly in shallow marine waters, under 100 m (330 ft) deep; however, some such as Navicula pennata have been recorded to a depth of 360 m (1,180 ft). A type of algae, Ancylonema nordenskioeldii, was found in
Greenland in areas known as the 'Dark Zone', which caused an increase in the rate of melting ice sheet. Same algae was found in the
Italian Alps, after pink ice appeared on parts of the Presena glacier.
The various sorts of algae play significant roles in aquatic ecology. Microscopic forms that live suspended in the water column (
phytoplankton) provide the food base for most marine
food chains. In very high densities (
algal blooms), these algae may discolor the water and outcompete, poison, or
asphyxiate other life forms.
Algae can be used as
indicator organisms to monitor pollution in various aquatic systems. In many cases, algal metabolism is sensitive to various pollutants. Due to this, the species composition of algal populations may shift in the presence of chemical pollutants. To detect these changes, algae can be sampled from the environment and maintained in laboratories with relative ease.
classical Chinese, the word 藻 is used both for "algae" and (in the modest tradition of the
imperial scholars) for "literary talent". The third island in
Kunming Lake beside the
Summer Palace in Beijing is known as the Zaojian Tang Dao, which thus simultaneously means "Island of the Algae-Viewing Hall" and "Island of the Hall for Reflecting on Literary Talent".
The majority of algae that are intentionally cultivated fall into the category of
microalgae (also referred to as
Macroalgae, commonly known as
seaweed, also have many commercial and industrial uses, but due to their size and the specific requirements of the environment in which they need to grow, they do not lend themselves as readily to cultivation (this may change, however, with the advent of newer seaweed cultivators, which are basically
algae scrubbers using upflowing air bubbles in small containers).
Global production of farmed aquatic plants, overwhelmingly dominated by seaweeds, grew in output volume from 13.5 million tonnes in 1995 to just over 30 million tonnes in 2016. Cultured microalgae already contribute to a wide range of sectors in the emerging
bioeconomy. Research suggests there are large potentials and benefits of algaculture for the development of a future
sustainable food system.
Global production of farmed aquatic plants, overwhelmingly dominated by seaweeds, grew in output volume from 13.5×10^6 t (13,300,000 long tons; 14,900,000 short tons) in 1995 to just over 30×10^6 t (30,000,000 long tons; 33,000,000 short tons) in 2016. As of 2014, seaweed was 27% of all marine
algae bioreactor is used for cultivating
macro algae. Algae may be cultivated for the purposes of
biomass production (as in a
CO2 fixation, or aquarium/pond filtration in the form of an
algae scrubber. Algae bioreactors vary widely in design, falling broadly into two categories: open reactors and enclosed reactors. Open reactors are exposed to the atmosphere while enclosed reactors, also commonly called
photobioreactors, are isolated to varying extents from the atmosphere. Specifically, algae bioreactors can be used to produce fuels such as
bioethanol, to generate animal feed, or to reduce pollutants such as
CO2 in flue gases of power plants. Fundamentally, this kind of bioreactor is based on the
photosynthetic reaction, which is performed by the
chlorophyll-containing algae itself using dissolved carbon dioxide and sunlight energy. The carbon dioxide is dispersed into the reactor fluid to make it accessible for the algae. The bioreactor has to be made out of transparent material.
gelatinous substance derived from red algae, has a number of commercial uses. It is a good medium on which to grow bacteria and fungi, as most microorganisms cannot digest agar.
Alginic acid, or alginate, is extracted from
brown algae. Its uses range from gelling agents in food, to medical dressings. Alginic acid also has been used in the field of
biotechnology as a
biocompatible medium for cell encapsulation and cell immobilization.
Molecular cuisine is also a user of the substance for its gelling properties, by which it becomes a delivery vehicle for flavours.
To be competitive and independent from fluctuating support from (local) policy on the long run, biofuels should equal or beat the cost level of fossil fuels. Here, algae-based fuels hold great promise, directly related to the potential to produce more biomass per unit area in a year than any other form of biomass. The break-even point for algae-based biofuels is estimated to occur by 2025.
This kind of ore they often gather and lay on great heapes, where it heteth and rotteth, and will have a strong and loathsome smell; when being so rotten they cast on the land, as they do their muck, and thereof springeth good corn, especially barley ... After spring-tydes or great rigs of the sea, they fetch it in sacks on horse backes, and carie the same three, four, or five miles, and cast it on the lande, which doth very much better the ground for corn and grass.
Today, algae are used by humans in many ways; for example, as
soil conditioners, and livestock feed. Aquatic and microscopic species are cultured in clear tanks or ponds and are either harvested or used to treat effluents pumped through the ponds.
Algaculture on a large scale is an important type of
aquaculture in some places.
Maerl is commonly used as a soil conditioner.
Sewage can be treated with algae, reducing the use of large amounts of toxic chemicals that would otherwise be needed.
Algae can be used to capture fertilizers in runoff from farms. When subsequently harvested, the enriched algae can be used as fertilizer.
Aquaria and ponds can be filtered using algae, which absorb nutrients from the water in a device called an
algae scrubber, also known as an algae turf scrubber.
Agricultural Research Service scientists found that 60–90% of nitrogen runoff and 70–100% of phosphorus runoff can be captured from
manure effluents using a horizontal algae scrubber, also called an
algal turf scrubber (ATS). Scientists developed the ATS, which consists of shallow, 100-foot raceways of nylon netting where algae colonies can form, and studied its efficacy for three years. They found that algae can readily be used to reduce the nutrient runoff from agricultural fields and increase the quality of water flowing into rivers, streams, and oceans. Researchers collected and dried the nutrient-rich algae from the ATS and studied its potential as an organic fertilizer. They found that cucumber and corn seedlings grew just as well using ATS organic fertilizer as they did with commercial fertilizers. Algae scrubbers, using bubbling upflow or vertical waterfall versions, are now also being used to filter aquaria and ponds.
Various polymers can be created from algae, which can be especially useful in the creation of bioplastics. These include hybrid plastics, cellulose-based plastics, poly-lactic acid, and bio-polyethylene. Several companies have begun to produce algae polymers commercially, including for use in flip-flops and in surf boards.
chlorophylls) produced by algae can be used as alternatives to chemical
dyes and coloring agents.
The presence of some individual algal pigments, together with specific pigment concentration ratios, are taxon-specific: analysis of their concentrations with various analytical methods, particularly
high-performance liquid chromatography, can therefore offer deep insight into the taxonomic composition and relative abundance of natural algae populations in sea water samples.
^Harvey, D. (1836).
"Algae"(PDF). In Mackay, J. T. (ed.). Flora hibernica comprising the Flowering Plants Ferns Characeae Musci Hepaticae Lichenes and Algae of Ireland arranged according to the natural system with a synopsis of the genera according to the Linnaean system. pp. 157–254.
Archived(PDF) from the original on 9 October 2022. Retrieved 31 December 2017..
^Brodo et al. (2001), p. 6: "A species of lichen collected anywhere in its range has the same lichen-forming fungus and, generally, the same photobiont. (A particular photobiont, though, may associate with scores of different lichen fungi)."
^Lane, Katie; Derbyshire, Emma; Li, Weili; Brennan, Charles (January 2014). "Bioavailability and Potential Uses of Vegetarian Sources of Omega-3 Fatty Acids: A Review of the Literature". Critical Reviews in Food Science and Nutrition. 54 (5): 572–579.
^Buschmann, Alejandro H.; Camus, Carolina; Infante, Javier; Neori, Amir; Israel, Álvaro; Hernández-González, María C.; Pereda, Sandra V.; Gomez-Pinchetti, Juan Luis; Golberg, Alexander; Tadmor-Shalev, Niva; Critchley, Alan T. (2 October 2017). "Seaweed production: overview of the global state of exploitation, farming and emerging research activity". European Journal of Phycology. 52 (4): 391–406.
^Ask, E.I (1990). Cottonii and Spinosum Cultivation Handbook. Philippines: FMC BioPolymer Corporation. p. 52.
^Lewis, J. G.; Stanley, N. F.; Guist, G. G. (1988). "9. Commercial production of algal hydrocolloides". In Lembi, C. A.; Waaland, J. R. (eds.). Algae and Human Affairs. Cambridge University Press.
^McHugh, Dennis J. (2003).
"9, Other Uses of Seaweeds". A Guide to the Seaweed Industry: FAO Fisheries Technical Paper 441. Rome: Fisheries and Aquaculture Department, Food and Agriculture Organization (FAO) of the United Nations.
Archived from the original on 28 December 2008.
^Arad, Shoshana; Spharim, Ishai (1998). "Production of Valuable Products from Microalgae: An Emerging Agroindustry". In Altman, Arie (ed.). Agricultural Biotechnology. Books in Soils, Plants, and the Environment. Vol. 61. CRC Press. p. 638.
^Latasa, M.; Bidigare, R. (1998). "A comparison of phytoplankton populations of the Arabian Sea during the Spring Intermonsoon and Southwest Monsoon of 1995 as described by HPLC-analyzed pigments". Deep-Sea Research Part II. 45 (10–11): 2133–2170.
Fritsch, F. E. (1945) . The Structure and Reproduction of the Algae. Vol. I & II. Cambridge University Press.
van den Hoek, C.; Mann, D. G.; Jahns, H. M. (1995). Algae: An Introduction to Phycology. Cambridge University Press.
Kassinger, Ruth (2020). Slime: How Algae Created Us, Plague Us, and Just Might Save Us. Mariner.
Lembi, C. A.; Waaland, J.R. (1988). Algae and Human Affairs. Cambridge University Press.
Mumford, T. F.; Miura, A. (1988). "Porphyra as food: cultivation and economic". In Lembi, C. A.; Waaland, J. R. (eds.). Algae and Human Affairs. Cambridge University Press. pp. 87–117.
Brodie, Juliet; Burrows, Elsie M.; Chamberlain, Yvonne M.; Christensen, Tyge; Dixon, Peter Stanley; Fletcher, R. L.; Hommersand, Max H.; Irvine, Linda M.; Maggs, Christine A. (1977–2003). Seaweeds of the British Isles: A Collaborative Project of the British Phycological Society and the British Museum (Natural History). London / Andover: British Museum of Natural History, HMSO / Intercept.
Cullinane, John P. (1973). Phycology of the South Coast of Ireland. Cork: Cork University Press.
Hardy, F. G.; Aspinall, R. J. (1988). An Atlas of the Seaweeds of Northumberland and Durham. The Hancock Museum, University Newcastle upon Tyne: Northumberland Biological Records Centre.
Hardy, F. G.;
Guiry, Michael D.; Arnold, Henry R. (2006). A Check-list and Atlas of the Seaweeds of Britain and Ireland (Revised ed.). London: British Phycological Society.
John, D. M.; Whitton, B. A.; Brook, J. A. (2002). The Freshwater Algal Flora of the British Isles. Cambridge / New York: Cambridge University Press.
Knight, Margery; Parke, Mary W. (1931). Manx Algae: An Algal Survey of the South End of the Isle of Man. Liverpool Marine Biology Committee Memoirs on Typical British Marine Plants & Animals. Vol. XXX. Liverpool: University Press.
Morton, Osborne (1 December 2003). "The Marine Macroalgae of County Donegal, Ireland". Bulletin of the Irish Biogeographical Society. 27: 3–164.
Huisman, J. M. (2000). Marine Plants of Australia. University of Western Australia Press.
Chapman, Valentine Jackson; Lindauer, VW; Aiken, M.; Dromgoole, F. I. (1970) [1900, 1956, 1961, 1969]. The Marine algae of New Zealand. London / Lehre, Germany: Linnaean Society of London / Cramer.
Cabioc'h, Jacqueline; Floc'h, Jean-Yves; Le Toquin, Alain; Boudouresque, Charles-François; Meinesz, Alexandre; Verlaque, Marc (1992). Guide des algues des mers d'Europe: Manche/Atlantique-Méditerranée (in French). Lausanne, Suisse: Delachaux et Niestlé.
Gayral, Paulette (1966). Les Algues de côtes françaises (manche et atlantique), notions fondamentales sur l'écologie, la biologie et la systématique des algues marines (in French). Paris: Doin, Deren et Cie.
Míguez Rodríguez, Luís (1998). Algas mariñas de Galicia: Bioloxía, gastronomía, industria (in Galician). Vigo: Edicións Xerais de Galicia.
Otero, J. (2002). Guía das macroalgas de Galicia (in Galician). A Coruña: Baía Edicións.
Bárbara, I.; Cremades, J. (1993). Guía de las algas del litoral gallego (in Spanish). A Coruña: Concello da Coruña – Casa das Ciencias.
Kjellman, Frans Reinhold (1883). The algae of the Arctic Sea: A survey of the species, together with an exposition of the general characters and the development of the flora. Vol. 20. Stockholm: Kungl. Svenska vetenskapsakademiens handlingar. pp. 1–350.
Lund, Søren Jensen (1959). The Marine Algae of East Greenland. Kövenhavn: C.A. Reitzel. 9584734.
Børgesen, Frederik (1970) . "Marine Algae". In Warming, Eugene (ed.). Botany of the Faröes Based Upon Danish Investigations, Part II. Copenhagen: Det nordiske Forlag. pp. 339–532..
Børgesen, Frederik (1936) [1925, 1926, 1927, 1929, 1930]. Marine Algae from the Canary Islands. Copenhagen: Bianco Lunos.
Gayral, Paulette (1958). Algues de la côte atlantique marocaine (in French). Casablanca: Rabat [Société des sciences naturelles et physiques du Maroc].
Stegenga, H.; Bolton, J. J.; Anderson, R. J. (1997). Seaweeds of the South African West Coast. Bolus Herbarium, University of Cape Town.
Abbott, I. A.; Hollenberg, G. J. (1976). Marine Algae of California. California: Stanford University Press.
"Algae Research". National Museum of Natural History, Department of Botany. 2008. Archived from
the original on 1 December 2008. Retrieved 19 December 2008.
Anderson, Don; Keafer, Bruce; Kleindinst, Judy; Shaughnessy, Katie; Joyce, Katherine; Fino, Danielle; Shepherd, Adam (2007).
"Harmful Algae". US National Office for Harmful Algal Blooms.
Archived from the original on 5 December 2008. Retrieved 19 December 2008.