Sea salad

Sea salad
	Sea lettuce ( ulva lactuca )
Systematics
Trunk :	Chlorophyta
Class :	Ulvophyceae
Order :	Ulvales
Family :	Ulvaceae
Genre :	Ulva
Type :	Sea salad
Scientific name
	Ulva lactuca
	L. , 1753

Herable copy

Sea lettuce ( Ulva lactuca ), also known as sea lettuce, is a multicellular green alga that is found on the sea coasts almost all over the world. Your thallus resembles a limp leaf of lettuce. The alga is consumed as food and used as feed and fertilizer.

features

The sea lettuce usually reaches a diameter of 20-30 centimeters (rarely more than a meter). It is attached to the ground with a disc-shaped adhesive organ. The light green to grass green thallus has a short stalk or almost sessile, it is flat, limp and smooth and reminiscent of a lettuce leaf. Its shape is more or less rounded, often widened at the end and sometimes lobed, wavy at the edge. It consists of two layers of slightly elongated cells.

Ulva has an isomorphic generation change , which means that the diploid sporophyte can hardly be distinguished externally from the haploid gametophyte . Spores are mostly formed in coastal areas exposed to surf. The sporophytes have a dark green border. The gametophytes are sexually separated, male thalli have a yellowish, female an olive-green edge zone. After emptying the reproductive organs, the marginal areas look colorless. For reproduction and development see also article Ulva .

Occurrence

The sea lettuce is found on almost every coast of the world, with the exception of Antarctica. It is also widespread in the North Sea and the Baltic Sea .

It thrives from the intertidal zone to the shallow sublittoral , often in tidal pools , and is occasionally found floating freely. It grows lithophytically on stones as well as epiphytically on larger algae like fucus or on mussel shells (especially the cockle ). It needs a lot of sunlight and can sometimes form dense stands up to a depth of 1 m. Overall, it can survive to a depth of 15 m.

Systematics

Ulva lactuca was first described by Carl von Linné in Species Plantarum 2 in 1753 . This is the type species of the genus Ulva . The type specimen comes from the west coast of Sweden. Synonyms are Phyllona lactuca (L.) FHWiggers, Monostroma lactuca (L.) J. Agardh, Ulva lactucaefolia SFGray, Ulva fenestrata Postels & Ruprecht and Ulva crassa Kjellman 1877.

Usage and Problems

The sea lettuce is consumed as a food on many coasts , for example in East Asia, on the Pacific coast of North America, in Ireland and France. It is used raw as a salad or ground in bread to keep it moist longer. It is also part of pasta and seasoning mixes. It has a high content of vitamin C , proteins, iron and iodine.

In agriculture, sea lettuce is used as a feed supplement for livestock and as a fertilizer.

The sea lettuce can also be cultivated on rocky ground, where it can sometimes be harvested twice a year.

The growth of Ulva lactuca is strongly encouraged in nutrient-rich locations . In 2009, due to the entry of nitrates from fertilizers into the oceans, there was a massive increase in algae in Brittany . Their rotting remains polluted the beaches, releasing methane and toxic hydrogen sulfide . The rapid growth of Ulva lactuca at high nutrient concentrations also offers potential applications in bioremediation . Ulva lactuca can, for example , be cultivated in the context of ecological aquaculture in nutrient-rich wastewater from fish, mussel or shrimp aquaculture .

The use of sea lettuce as a source of bioenergy and bio-based plastics is being tested.

literature

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ Wolfram Braune: Marine algae. A color guide to the common benthic green, brown and red algae of the world's oceans. Gantner, Ruggell 2008, ISBN 978-3-906166-69-8 , pp. 40-41.
↑ ^a ^b ^c ^d ^e P. Kornmann, PH Sahling: Sea algae from Helgoland - Benthic green, brown and red algae. Biological establishment Helgoland, Hamburg 1983, ISSN 0017-9957 , pp. 64-66.
↑ ^a ^b ^c ^d Marianne Køie, Aase Kristiansen: The great cosmos beach guide. Animals and plants in the North and Baltic Seas. With drawings by Susanne Weitemeyer. Franckh-Kosmos, Stuttgart 2001, ISBN 3-440-08576-7 .
↑ Dirk Schories, Uwe Selig, Hendrik Schubert: Species and synonym list of the German marine macroalgae based on historical and recent records (list of species and synomes of macroalgae in German coastal waters - evaluation of historical and recent findings). In: Rostock. Marine biologist Contribution issue 21, 2009, p. 36. (biologie.uni-rostock.de , PDF)
↑ Carl von Linné: Species Plantarum. Volume 2, 1753, p. 1163. (biodiversitylibrary.org) .
↑ Michael D. Guiry in Michael D. Guiry, G. M Guiry: Ulva lactuca . In: Algaebase - World-wide electronic publication. National University of Ireland, Galway, accessed July 3, 2018.
↑ Michael Guiry: Ulva lactuca. The Seaweed Site: information on marine algae, accessed July 3, 2018.
↑ Michael Hirst: Toxic seaweed clogs French coast. In: BBC News. August 11, 2009.
↑ Annette Bruhn, Jonas Dahl, Henrik Bangsø Nielsen, Lars Nikolaisen, Michael Bo Rasmussen, Stiig Markager, Birgit Olesen, Carlos Arias, Peter Daugbjerg Jensen: Bioenergy potential of Ulva lactuca: Biomass yield, methane production and combustion. In: Bioresource Technology. Volume 102, 2011, pp. 2595-2604. (PDF)
^ Sander WK van den Burg, Fiona Moejes, Julie Maguire, Helena Abreu, Maud Benoit: Environmental Impacts of Experimental Production of Lactic Acid for Bioplastics from Ulva spp. In: Sustainability . tape 10 , no. 7 , July 2018, p. 2462 , doi : 10.3390 / su10072462 ( mdpi.com [accessed March 17, 2019]).

Web links

Commons : Ulva lactuca - album with pictures, videos and audio files

[Braune-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ Wolfram Braune: Marine algae. A color guide to the common benthic green, brown and red algae of the world's oceans. Gantner, Ruggell 2008, ISBN 978-3-906166-69-8 , pp. 40-41.

[Kornmann-2] P. Kornmann, PH Sahling: Sea algae from Helgoland - Benthic green, brown and red algae. Biological establishment Helgoland, Hamburg 1983, ISSN 0017-9957 , pp. 64-66.

[Køie-3] Marianne Køie, Aase Kristiansen: The great cosmos beach guide. Animals and plants in the North and Baltic Seas. With drawings by Susanne Weitemeyer. Franckh-Kosmos, Stuttgart 2001, ISBN 3-440-08576-7 .

[Schories-4] Dirk Schories, Uwe Selig, Hendrik Schubert: Species and synonym list of the German marine macroalgae based on historical and recent records (list of species and synomes of macroalgae in German coastal waters - evaluation of historical and recent findings). In: Rostock. Marine biologist Contribution issue 21, 2009, p. 36. (biologie.uni-rostock.de , PDF)

[Linné-5] Carl von Linné: Species Plantarum. Volume 2, 1753, p. 1163. (biodiversitylibrary.org) .

[Algaebase-6] Michael D. Guiry in Michael D. Guiry, G. M Guiry: Ulva lactuca . In: Algaebase - World-wide electronic publication. National University of Ireland, Galway, accessed July 3, 2018.

[Guiry-7] Michael Guiry: Ulva lactuca. The Seaweed Site: information on marine algae, accessed July 3, 2018.

[Hirst-8] Michael Hirst: Toxic seaweed clogs French coast. In: BBC News. August 11, 2009.

[Bruhn-9] Annette Bruhn, Jonas Dahl, Henrik Bangsø Nielsen, Lars Nikolaisen, Michael Bo Rasmussen, Stiig Markager, Birgit Olesen, Carlos Arias, Peter Daugbjerg Jensen: Bioenergy potential of Ulva lactuca: Biomass yield, methane production and combustion. In: Bioresource Technology. Volume 102, 2011, pp. 2595-2604. (PDF)

[10] Sander WK van den Burg, Fiona Moejes, Julie Maguire, Helena Abreu, Maud Benoit: Environmental Impacts of Experimental Production of Lactic Acid for Bioplastics from Ulva spp. In: Sustainability . tape 10 , no. 7 , July 2018, p. 2462 , doi : 10.3390 / su10072462 ( mdpi.com [accessed March 17, 2019]).