Fucus vesiculosus

Bladderwrack (Fucus vesiculosus)

The bladder wrack (Fucus vesiculosus) is a widely used in the North Atlantic and in the North Sea and Baltic algae from the class of brown algae. It is used, inter alia, as a remedy. His stocks in the Baltic Sea have declined drastically in recent years.

• 3.1 decline in the Baltic Sea

• 6.1 ingredients
• 6.2 Medical use
• 6.3 Other Terms

• 7.1 Notes and references

Trivial names

Popular Bladderwrack also sea oak, sea oak, Bläretung, Höckertang or Schweinetang was called.

Description

The bladder is a perennial Großalge (seaweed) with a length of usually 10 to 30 cm (rarely longer). On the base it is connected to an adhesive plate with the ground. The leathery, rough, brown-green thallus is flattened, dichotomously branched in one plane and traversed by a midrib. Characteristic design and name of the gas bubbles that are arranged on both sides of the midrib in pairs and are available individually in the bifurcations. They give the algae buoyancy in the water. At low tide, the bladder is protected by a layer of mucus from drying out.

Propagation

Fucus species are diploid generation without change. In summer, at the Thallusenden swollen fruit bodies with gelatinous content and warty surface. These so-called seminal receptacles contain jug -shaped recessed Konzeptakeln in which the gametes, ova and zoospores are formed. Male and female gametes are formed on different thalli when bladderwrack ( dioecious ). A rising tide gametes exit through the pore-like openings of the Konzeptakeln. The eggs but a pheromone from ( Fucoserraten ) that attracts the sperm. The gametes are two hours maximum viable and spread at most 2 to 10 meters far from. The fertilized zygote establishes itself and grows into a new diploid thallus zoom.

The main maturity period ranges from September to May In June and July last year, the degenerate fruiting bodies and to develop new Thallusenden seminal receptacles.

Occurrence

The distribution area of bladderwrack includes the coastal regions in the North Atlantic. From Northern Europe, the North Sea and Baltic Sea it is disseminated to the Canary Islands and Morocco. In America it occurs from Canada to the Caribbean, and on the coast of Brazil, he was found.

It grows in the surf zone and upper intertidal zone on a solid surface such as rocks, stones and wood.

At the German North Sea ( German Bight) there are sizeable populations especially in Helgoland. In the Wadden Sea is limited to the bladder walls and mussel beds.

Decline in the Baltic Sea

On the German Baltic coast of the bladder was common until the 20th century on hard substrate everywhere and came up at depths 10-14 meters in front. Since 2004, an extreme decline was here, especially in the Gulf of Mecklenburg, was observed. Today you can find only a few individual Tange and only two stocks ( Wustrow and salt lagoon ), which are restricted to the shallow water up to 2 m water depth. This decrease could be explained neither by the salinity of the water, nor by the availability of light or hard substrate. The cause of this competition for space with mussels, feeding be accepted by isopods or damage to the germ cells by oil pollution.

Also in the Bay of Kiel grow most Tange only at a depth of 2 meters, individual specimens are up to 3.5 meters depth before. The potentially enabled by the light growth limit was established here at 4-6 meters depth. It is believed that the green cover shades the Tange by algae or sessile barnacles and thus prevents the penetration to greater depths.

Ecology

The sea isopods of the genus Idotea feed on the seaweeds. The Tallus of bladderwrack is seated by algae colonized ( epiphytes ), for example Ceramium and Enteromorpha and Elachista fucicola. As sessile animals occur polychaete ( Polydora ) and barnacles ( Balanus improvisus ) that the latter can almost completely cover the Tange especially in deeper water.

System

The first description of Fucus vesiculosus was made in 1753 by Carl Linnaeus in Species Plantarum, Volume 2, page 1158. This species is the type species ( lectotype ) of the genus Fucus.

Synonyms of Fucus vesiculosus L. are Halidrys vesiculosus (L.) Stackhouse and Virsodes vesiculosum (L.) Kuntze. As more synonyms apply Fucus axillaris var subecostatus J.Agardh, Fucus axillary f balticus ( C.Agardh ) Kjellman, Fucus balticus C.Agardh, Fucus divaricatus L., Fucus excisus Forsskål and Fucus inflatus L.

From Bladderwrack also a form exists without gas bubbles, which occurs exposed to strong surf spots. The following varieties of Fucus vesiculosus be distinguished ( Guiry in AlgaeBase, 2012):

• Compressus var Kjellman
• Var vadorum Areschoug
• Var linearis (Hudson ) Kützing
• Volubilis var Goodenough & Woodward
• F mytili ( Nienburg ) Nienhuis

Use

Bladderwrack is extensively used as animal food, food additive, in the fertilizer industry, for industrial applications and food processing. The harvest takes place exclusively from wild stocks. The specified quantity harvested (2005: 84 t) seems low compared with other kelp species.

Ingredients

Bladderwrack contains up to 0.1 to 0.5 % of iodine, also bromine, beta-carotene, alginic acid, polyphenols having antibiotic activity, xanthophylls ( fucoxanthin ), polysaccharides, and pectin- mucilage. For mucilage fucoidan an immunostimulating effect in cancer has been demonstrated. In addition, the bladder has a high content of minerals and trace elements. Like all algae he accumulates arsenic and heavy metals such as lead and cadmium, which are detectable in the prepared products.

Medical use

The pharmaceutical industry uses bladderwrack for the extraction of alginates. The bladder is used in Ireland and France for the production of kelp extract for cosmetic products. As Tangbäder the dried algae are also used in thalassotherapy.

Due to its high iodine content bladderwrack has been used to treat goiter since the 17th century. In herbal medicine it is used for hypothyroidism, hay fever, atherosclerosis and psoriasis. To avoid overdosing with iodine, it should not be used in hyperthyroidism and during lactation and pregnancy.

As has been suggested that the active ingredients of bladderwrack increase the basal metabolic rate, it was also used for the treatment of obesity since the mid-19th century. Today, Bladderwrack is part of many slimming products. On the Internet, both plant and homeopathic products are available.

Further use

In Scotland, bladderwrack has been used as fertilizer. Today, micro - nutrients and feed are obtained in animal husbandry from him. Local Bladderwrack is used as a packaging material for the lobster breeding and transportation of Pierwürmern. One possible use as a fuel ( renewable resource ) is investigated.

Swell

• P. Korn man P.H. Sahling: seaweed from Helgoland - Benthic green, brown and red algae. Biologische Anstalt Helgoland, Hamburg, 1983. ISSN 0017-9957, pp. 162-165. (Sections description, multiplication)