![Sargassum muticum Yendo Fensholt 1955 Lamiot WimmereuxHautsDeFrance Estran Juillet 2016a8](https://upload.wikimedia.org/wikipedia/commons/b/b4/Sargassum_muticum_Yendo_Fensholt_1955_Lamiot_WimmereuxHautsDeFrance_Estran_Juillet_2016a8.jpg)
''Sargassum muticum'', commonly known as Japanese wireweed, is a large brown seaweed of the genus ''
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 re ...
''. It is an invasive seaweed with high growth rate (up to 10 cm per day during spring). It has an efficient dispersion thanks to its floats.
Description
''Sargassum muticum'' is a brown seaweed, normally brown to yellowish with a length up to 10 m. It is an
autotroph
An autotroph or primary producer is an organism that produces complex organic compounds (such as carbohydrates, fats, and proteins) using carbon from simple substances such as carbon dioxide,Morris, J. et al. (2019). "Biology: How Life Works", ...
that uses energy from sunlight. The photosynthesis is facilitated thanks to aerial vesicles which allow the algae to rise to the surface.
''Sargassum muticum'' is composed of two distinct parts: a perennial part, which contains the holdfast and one or more short main axes; and an annual part: the secondary axes, which develop on the main axis, whose growth is unlimited and whose size is variable. There are three types of ramifications: laterals with foliaceous expansions called fronds, laterals with fronds and aerocysts and laterals with fronds, aerocysts and reproductive organs called receptacles. In winter, only the perennial part persists (5 cm). In summer, the lateral part is in maximum development of 2–3 meters to 10 meters.
Reproduction
The mode of reproduction is both
sexual
Sex is the biological distinction of an organism between male and female.
Sex or SEX may also refer to:
Biology and behaviour
*Animal sexual behaviour
**Copulation (zoology)
**Human sexual activity
**Non-penetrative sex, or sexual outercourse
** ...
and
asexual. ''S. muticum'' reaches sexual maturity in the summer when gamete production takes place in receptacles. The species is
monoecious
Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system alongside gynomonoecy, andromonoecy and trimonoecy.
Monoecy is conne ...
, i.e. an individual is capable of producing male and female gametes. Its cycle of development is
monogenic (i.e. only one generation is present during its life cycle). At the level of fertilization: male gametes are dispersed in seawater while female gametes remain in the receptacle where fertilization takes place). Development is also done at the receptacle and then once at the stage of seedling, the latter is detached for fixation on a new support and form a new individual. This species can also reproduce asexually, but this has never been observed in temperate environments.
Habitat
''Sargassum muticum'' grows from half-tide to infralittoral areas (to a depth of 10 m.
[Thomas D. N. (2002). ''Seaweeds.'' The Natural History Museum, London.]). It is fixed on solid substrates like rocks, stones, shells. It is highly tolerant towards temperature and salinity variations. The optimal temperature is between 17 and 20 °C but it tolerates -9 and 30 °C.
Repartition areas, invasiveness, impacts
Repartition areas
Originally from
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
, it is thought to have gained worldwide distribution through being transported with Japanese
oyster
Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not al ...
s (''
Crassostrea gigas
The Pacific oyster, Japanese oyster, or Miyagi oyster (''Magallana gigas''), is an oyster native to the Pacific coast of Asia. It has become an introduced species in North America, Australia, Europe, and New Zealand.
Etymology
The genus ''Ma ...
''). ''Sargassum muticum'' was introduced to the Californian coast in the 1940s and in Europe in the 1970s (The species was first found in the
British Isles
The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles, ...
in the
Isle of Wight
The Isle of Wight ( ) is a county in the English Channel, off the coast of Hampshire, from which it is separated by the Solent. It is the largest and second-most populous island of England. Referred to as 'The Island' by residents, the Isle of ...
in 1973). Currently, the alga is widespread from
Norway
Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...
to
Portugal
Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...
along
Atlantic
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...
coasts. ''Sargassum muticum'' has a range stretching from Campbell River,
British Columbia
British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...
to
Baja in
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
.
[Abbott I. A. & Hollenberg G. J. (1976). ''Marine Algae of California.'' Stanford University Press, California.] In
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
it extends along the coasts of
Great Britain
Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It is ...
,
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
,
Scandinavia
Scandinavia; Sámi languages: /. ( ) is a subregion#Europe, subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, ...
,
Baltic Sea
The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain.
The sea stretches from 53°N to 66°N latitude and from ...
,
Helgoland
Heligoland (; german: Helgoland, ; Heligolandic Frisian: , , Mooring Frisian: , da, Helgoland) is a small archipelago in the North Sea. A part of the German state of Schleswig-Holstein since 1890, the islands were historically possessions ...
,
Netherlands
)
, anthem = ( en, "William of Nassau")
, image_map =
, map_caption =
, subdivision_type = Sovereign state
, subdivision_name = Kingdom of the Netherlands
, established_title = Before independence
, established_date = Spanish Netherl ...
,
Ireland
Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...
, the
Iberian Peninsula
The Iberian Peninsula (),
**
* Aragonese and Occitan: ''Peninsula Iberica''
**
**
* french: Péninsule Ibérique
* mwl, Península Eibérica
* eu, Iberiar penintsula also known as Iberia, is a peninsula in southwestern Europe, defi ...
and into the
Mediterranean
The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the e ...
from
Italy
Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical re ...
and the
Adriatic
The Adriatic Sea () is a body of water separating the Italian Peninsula from the Balkans, Balkan Peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto (where it connects to the Ionian Sea) ...
. It is recorded from Japan,
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
and
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...
.
Recently, some specimens were found on
Moroccan coasts. This illustrates its huge tolerance regarding its environment.
Herbarium
A herbarium (plural: herbaria) is a collection of preserved plant specimens and associated data used for scientific study.
The specimens may be whole plants or plant parts; these will usually be in dried form mounted on a sheet of paper (called ...
specimens are now stored in the
Ulster Museum
The Ulster Museum, located in the Botanic Gardens in Belfast, has around 8,000 square metres (90,000 sq. ft.) of public display space, featuring material from the collections of fine art and applied art, archaeology, ethnography, treasure ...
(BEL catalogue numbers: F11241 - F11242; F11182 - F11185).
Invasiveness and impacts
Its proliferation is important especially during the summer, which causes economic and ecological problems.
Ecological: Because of its large size and dense ramifications, ''S.muticum'' forms a screen within the water column preventing the penetration of light. It also captures the nutrients in disfavor of other species such as
phytoplankton
Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater ecosystems. The name comes from the Greek words (), meaning 'plant', and (), meaning 'wanderer' or 'drifter'.
Ph ...
. However, ''S.muticum'' also serves as shelter and protection for fish larvae or crustaceans as well as laying support for cuttlefish.
Economic: ''S.muticum'' fixes itself to the shells of oysters, creating problems in shellfish farming through increased manual work to eliminate the algae. In addition, it can wrap around the farming structures, requiring additional maintenance. It also gets entangled with the propellers of the boats.
Options for removal
Mechanical removal—however this promotes dissemination of the species and the technique is labor-intensive.
Chemical—the use of
herbicide
Herbicides (, ), also commonly known as weedkillers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page fo ...
s is advised against, because it poses a major risk to the environment and other organisms.
Biological—there are few natural predators. One example is a little copepod that will eat only the unhealthy and damaged parts of ''S. muticum.''
Currently the distribution is stabilized, and only mechanical removal is performed.
Uses
There are some potential uses for ''Sargassum muticum.''
In agriculture, algae are used as sources of nitrate and potash for
fertilization
Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Proce ...
. It is also used in
aquaculture
Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. lot ...
as feed for juvenile sea cucumbers.
Water treatment
Water treatment is any process that improves the Water quality, quality of water to make it appropriate for a specific end-use. The end use may be drinking water, drinking, industrial water supply, irrigation, river flow maintenance, water recrea ...
: the cell walls of ''S. muticum'' contain
alginates
Alginic acid, also called algin, is a naturally occurring, edible polysaccharide found in brown algae. It is hydrophilic and forms a viscous gum when hydrated. With metals such as sodium and calcium, its salts are known as alginates. Its colour ...
and
fucoidan
Fucoidan is a long chain sulfated polysaccharide found in various species of brown algae. Commercially available fucoidan is commonly extracted from the seaweed species '' Fucus vesiculosus'', ''Cladosiphon okamuranus'', ''Laminaria japonica'' and ...
s. The association of both molecules forms a bigger molecule and this one can be a
flocculant. This process can be a method to catch organic matter present in sewage. This flocculant, rich in proteins and oligoelements, is easily
biodegradable
Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegradati ...
and could be used for fertilizer.
Previous studies have shown that ''Sargassum muticum'' is able to carry out the
biosorption Biosorption is a physiochemical process that occurs naturally in certain biomass which allows it to passively concentrate and bind contaminants onto its cellular structure. Biosorption can be defined as the ability of biological materials to accumu ...
of heavy metals like
cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of ...
,
chlorophenolic compounds, and
nickel
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...
.
Antifouling
Biofouling or biological fouling is the accumulation of microorganisms, plants, algae, or small animals where it is not wanted on surfaces such as ship and submarine hulls, devices such as water inlets, pipework, grates, ponds, and rivers that ...
: Secondary
metabolite
In biochemistry, a metabolite is an intermediate or end product of metabolism.
The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...
s produced by marine algae could be an interesting alternative antifouling agent. Previous studies have shown the potential of
hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ex ...
and
fatty acid
In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, fr ...
compounds in antifouling activities, compounds such as
galactolipid
Galactolipids are a type of glycolipid whose sugar group is galactose. They differ from glycosphingolipids in that they do not have nitrogen in their composition.
They are the main part of plant membrane lipids where they substitute phospholipids ...
s and
palmitic acid
Palmitic acid (hexadecanoic acid in IUPAC nomenclature) is a fatty acid with a 16-carbon chain. It is the most common saturated fatty acid found in animals, plants and microorganisms.Gunstone, F. D., John L. Harwood, and Albert J. Dijkstra. The Li ...
, 1-tetradecene or 1-hexadecene. Moreover, the peak production of antifouling compounds is during the spring.
Antioxidant
Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricant ...
compounds: ''Sargassum muticum'' is rich in antioxidant compounds such as
phenol
Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it req ...
ic
compounds (
cathechins,
phlorotannin
Phlorotannins are a type of tannins found in brown algae such as kelps and rockweeds or sargassacean species, and in a lower amount also in some red algae. Contrary to hydrolysable or condensed tannins, these compounds are oligomers of phlorogl ...
s,
quercetin
Quercetin is a plant flavonol from the flavonoid group of polyphenols. It is found in many fruits, vegetables, leaves, seeds, and grains; capers, red onions, and kale are common foods containing appreciable amounts of it. It has a bitter flavor a ...
s),
pigment
A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compo ...
s (
fucoxanthin
Fucoxanthin is a xanthophyll, with formula C42H58O6. It is found as an accessory pigment in the chloroplasts of brown algae and most other heterokonts, giving them a brown or olive-green color. Fucoxanthin absorbs light primarily in the blue-green ...
) and vitamins(
vitamin C
Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) an ...
,
K,
E in the form of
alpha-tocophérol and
gamma-tocopherol). Applications are possible in pharmaceuticals, cosmetics and health fields, thanks to the antioxidant activities of these molecules.
References
External links
''Sargassum muticum'' (aquatic plant) at Global Invasive Species DatabaseVideo footage of Japanese Wireweed in the Venice lagoon* http://www.algaebase.org/search/species/detail/?species_id=90
* http://habitas.org.uk/invasive/species.asp?item=432707
* http://www.observatoire-biodiversite-bretagne.fr/especes-invasives/Faune-et-flore-marines/Flore-marine/La-sargasse-Sargassum-muticum
* http://www.seaweed.ie/sargassum/index.php
{{Taxonbar, from=Q287682
Fucales
Flora of Japan
Marine biota of Asia