Zostera marina

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Zostera marina
Zostera marina - National Museum of Nature and Science, Tokyo - DSC07663.JPG
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Alismatales
Family: Zosteraceae
Genus: Zostera
Species:
Z. marina
Binomial name
Zostera marina
L.
Zostera marina dis.png
Global distribution of Zostera marina

Zostera marina is a flowering vascular plant species as one of many kinds of seagrass, with this species known primarily by the English name of eelgrass with seawrack much less used, and refers to the plant after breaking loose from the submerged wetland soil, and drifting free with ocean current and waves to a coast seashore. It is a saline soft-sediment submerged plant native to marine environments on the coastlines of northern latitudes from subtropical to subpolar regions of North America and Eurasia.

Contents

Distribution

This species is the most wide-ranging marine flowering plant in the Northern Hemisphere. [2] It lives in cooler ocean waters in the North Atlantic and North Pacific, and in the warmer southern parts of its range it dies off during warmer seasons. [3] It grows in the Arctic region and endures several months of ice cover per year. [4] It is the only seagrass known from Iceland. [4] It can be found in bays, lagoons, estuaries, on beaches, and in other coastal habitat. The several ecotypes each have specific habitat requirements.[ citation needed ] It occurs in calmer waters in the sublittoral zone, where it is rarely exposed to air. [3] It anchors via rhizomes in sandy or muddy substrates and its leaves catch particulate debris in the water which then collects around the bases of the plants, building up the top layer of the seabed. [3]

Description and reproduction

This flowering plant is a rhizomatous herb which produces a long stem with hairlike green leaves that measure up to 1.2 centimetres (0.47 in) wide and may reach over 1.0 metre (3 ft 3 in) long. It is a perennial plant, but it may grow as an annual. [5] The rhizome grows horizontally through the substrate, anchoring via clusters of roots at nodes. [3] The plant is monoecious, with an individual bearing both male and female flowers in separate alternating clusters. The inflorescence is about 10 cm long. [6] The fruit is a nutlet with a transparent coat containing the seed. The plant can also undergo vegetative reproduction, sprouting repeatedly from its rhizome and spreading into a meadow-like colony on the seabed known as a genet. [7] One meadow of cloned eelgrass was determined to be 3000 years old, genetically. [4] When undergoing sexual reproduction, the plant produces large quantities of seeds, at times numbering several thousand seeds per square meter of plants. [4] The plant disperses large distances when its stems break away and carry the fertile seeds to new areas, eventually dropping to the seabed. [4] The seagrass is a favorite food of several species of waterfowl, which may also distribute the seeds. [4]

Ecology

This Zostera grows in muddy and sandy shores only at and below spring tides. [6] This plant is an important member of the coastal ecosystem in many areas because it helps to physically form the habitat and it plays a crucial role for many other species. [4] [8] For example, it provides a sheltered spawning ground for the Pacific herring (Clupea pallasii). [8] Juvenile Atlantic cod (Gadus morhua) hide in eelgrass beds as they grow. [9] The blue mussel (Mytilus edulis) attaches to its leaves. [4] The green alga Entocladia perforans , an endophyte, depends on this eelgrass. [10] A great many animals use the plant for food, including the isopod Idotea chelipes and the purple sea urchin Paracentrotus lividus . [4] The Atlantic brant (Branta bernicula hrota) subsists almost entirely on the plant. [9] When the eelgrass dies, detaches, and washes up on the beach, a whole new ecosystem is founded; many species of insects and other invertebrates begin to inhabit the dead plant, including the amphipod Talitrus saltator , the fly Fucellia tergina , and the beetles Stenus biguttatus , Paederus littoralis , and Coccinella septempunctata . [11]

The bacterial species Granulosicoccus coccoides was first isolated from the leaves of the plant. [12]

Threats

Populations of the plant have been damaged by a number of processes, especially increased turbidity in the water; like most other plants, eelgrass requires sunlight to grow. [8] One plant may adapt to light level by growing longer leaves to reach the sun in low-light areas; individuals in clear or shallow water may have leaves a few centimeters long, while individuals in deeper spots may have leaves over a meter long. [4] Human activities such as dredging and trawling damage eelgrass meadows; practices used in scallop and mussel harvesting in the Wadden Sea have cleared much eelgrass from the sea bottom there. [4] Aquaculture operations and coastal development destroy colonies. [4] Pollution from many sources, including riverside farms, sewage lines, [13] fish processing plants, and oil spills, damage eelgrass meadows. [9] Conservation and restoration efforts of Zostera marina habitats [14] [15] have been plenty since their rapid decline started several decades ago.

Invasive species have been shown to have a negative effect on eelgrass and associated ecosystems. In Nova Scotia, the invasive exotic green crab (Carcinus maenas) destroys eelgrass when it digs in the substrate for prey items, [9] or by directly eating eelgrass seeds. [16] The decline of eelgrass in Antigonish Harbour has resulted in fewer Canada geese, which feed on the rhizome, and fewer common goldeneye, which eat invertebrates that live in eelgrass meadows. [9]

The slime mold Labyrinthula zosterae caused a "wasting disease" of eelgrass resulting in large-scale losses in the 1930s; localized populations are still affected by the slime mold today. [4] During this time, populations of the eelgrass-eating Atlantic brant dropped. [9] Remaining geese ate less-preferred food plants and algae, and hunters subsequently noticed that brant meat began to taste different. [9] Even today, brants no longer migrate over the Nova Scotia area. [9]

Genomics and evolutionary adaptations

The Zostera marina genome has been sequenced and analyzed by Olsen et al. in 2016 and the resulting article has been published in Nature. [17] The approximate genome sequence of Z. marina is 202.3 Mb and encodes approximately 20450 protein-coding genes (of which 86,6% are supported by transcriptome data). The assembled genome was found to consist of large numbers of repeat elements accounting for 63% of the assembled genome. The researchers revealed key adaptations at the molecular biological level that have occurred during evolution of Z. marina, an angiosperm that has adopted a marine lifestyle. Genome analysis revealed that Z. marina lost the entire repertoire of stomatal genes, genes involved in volatile compound biosynthesis and signaling (such as ethylene and terpenoids) as well as genes for ultraviolet protection and phytochromes used for far-red sensing. Besides these gene losses, also gene gain events have been described, mostly involving the adjustment to full salinity and ion homeostasis. Also macro-algae like cell wall components (low-methylated polyanionic pectins and sulfated galactans) have been described, unique for Z. marina compared to other angiosperms.

Human uses

People have long used this plant species as roof thatching in some areas. [4] It has been used as fertilizer and cattle fodder in Norway for centuries. [18] It has also been dried and used as stuffing for mattresses and furniture. [18] The Seri hunter gatherers of Mexico eat eelgrass grains after toasting them and grinding into a paste.

Ángel León, a Spanish chef, has planted meadows of Z. marina (described as "sea rice") in the Bay of Cádiz in order to harvest the grains. The texture is described as between rice and quinoa, but with a more saline flavour. It is gluten-free and high in fibre. [19]

Related Research Articles

<span class="mw-page-title-main">Seagrass</span> Plants that grow in marine environments

Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families, all in the order Alismatales. Seagrasses evolved from terrestrial plants which recolonised the ocean 70 to 100 million years ago.

<i>Zostera</i> Genus of aquatic plants

Zostera is a small genus of widely distributed seagrasses, commonly called marine eelgrass, or simply seagrass or eelgrass, and also known as seaweed by some fishermen and recreational boaters including yachtsmen. The genus Zostera contains 15 species.

<span class="mw-page-title-main">Zosteraceae</span> Family of aquatic plants

Zosteraceae is a family of marine perennial flowering plants found in temperate and subtropical coastal waters, with the highest diversity located around Korea and Japan. Most seagrasses complete their entire life cycle under water, having filamentous pollen especially adapted to dispersion in an aquatic environment and ribbon-like leaves that lack stomata. Seagrasses are herbaceous and have prominent creeping rhizomes. A distinctive characteristic of the family is the presence of characteristic retinacules, which are present in all species except members of Zostera subgenus Zostera.

<span class="mw-page-title-main">Seagrass meadow</span> Underwater ecosystem

A seagrass meadow or seagrass bed is an underwater ecosystem formed by seagrasses. Seagrasses are marine (saltwater) plants found in shallow coastal waters and in the brackish waters of estuaries. Seagrasses are flowering plants with stems and long green, grass-like leaves. They produce seeds and pollen and have roots and rhizomes which anchor them in seafloor sand.

<i>Halophila johnsonii</i> Species of aquatic plant

Halophila johnsonii, or Johnson's seagrass, is a small, asexual seagrass in the family Hydrocharitaceae. It occurs only on the southeastern coast of Florida, and was the first marine plant listed on the United States endangered species list, though it was removed from listing in April 2022. Female flowers have been observed, but even with decade long observational studies, neither male flowers nor seed have ever been observed.

<i>Posidonia oceanica</i> Species of marine plant

Posidonia oceanica, commonly known as Neptune grass or Mediterranean tapeweed, is a seagrass species that is endemic to the Mediterranean Sea. It forms large underwater meadows that are an important part of the ecosystem. The fruit is free floating and known in Italy as "the olive of the sea". Balls of fibrous material from its foliage, known as egagropili or Neptune balls, wash up to nearby shorelines.

The Seagrasses of Western Australia are submerged flowering plants found along the coast, around islands, and in Estuaries of Western Australia. The region contains some of the largest seagrass meadows in the world, and is the most diverse in the number of species. The variety of habitats along its western and southern coasts is often soft sands in shallow subtropical waters, ideal for these plants.

<i>Thalassia testudinum</i> Species of aquatic plant

Thalassia testudinum, commonly known as turtlegrass, is a species of marine seagrass. It forms meadows in shallow sandy or muddy locations in the Caribbean Sea and the Gulf of Mexico. Turtle grass and other seagrasses form meadows which are important habitats and feeding grounds. The grass is eaten by turtles and herbivorous fish, supports many epiphytes, and provides habitat for juvenile fish and many invertebrate taxa.

<i>Cymodocea nodosa</i> Species of plant in the family Cymodoceaceae

Cymodocea nodosa is a species of seagrass in the family Cymodoceaceae and is sometimes known as little Neptune grass. As a seagrass, it is restricted to growing underwater and is found in shallow parts of the Mediterranean Sea and certain adjoining areas of the Atlantic Ocean.

<i>Halophila decipiens</i> Species of aquatic plant

Halophila decipiens, commonly known as Caribbean seagrass or paddle grass, is a seagrass in the family Hydrocharitaceae. It grows underwater on sandy or muddy sea floors in shallow parts of tropical seas.

<i>Syringodium filiforme</i> Species of aquatic plant

Syringodium filiforme, commonly known as manatee grass, is a species of marine seagrass. It forms meadows in shallow sandy or muddy locations in the Caribbean Sea and the Gulf of Mexico, and is also found in the Bahamas and Bermuda. It occurs to a depth of about 20 m (66 ft), and even deeper where water is very clear.

<i>Halodule wrightii</i> Species of plant in the family Cymodoceaceae

Halodule wrightii is an aquatic plant in the Cymodoceaceae family. It is referred to by the common names shoal grass or shoalweed, and is a plant species native to seacoasts of some of the warmer oceans of the world.

<i>Zostera noltii</i> Species of plant

Zostera noltii is a species of seagrass known by the common name dwarf eelgrass. It is found in shallow coastal waters in north western Europe, the Mediterranean Sea, Black Sea, Caspian Sea and Aral Sea and on islands in the Atlantic off the coast of northwest Africa. It is an important part of the intertidal and shallow subtidal ecosystems of estuaries, bays and lagoons.

<i>Plasmodiophora bicaudata</i>

Plasmodiophora bicaudata is a marine pathogen, an obligate parasite of seagrass of the genus Zostera and the causal agent of wasting disease in the genus. These marine plants grow in fine sediment in shallow seas and the pathogen seems to have a worldwide distribution.

Zostera novazelandica Setchell is a species of seagrass in the family Zosteraceae found on the shores of New Zealand. It is regarded as a distinct species by some authors but considered as a synonym of Zostera muelleri Irmisch ex Ascherson by others. The Maori names for Zostera novazelandica are karepō, nana, rehia, and rimurehia.

<i>Zostera japonica</i> Species of plant

Zostera japonica is a species of aquatic plant in the Zosteraceae family. It is referred to by the common names dwarf eelgrass or Japanese eelgrass, and is native to the seacoast of eastern Asia from Russia to Vietnam, and introduced to the western coast of North America. It is found in the intertidal zone and the shallow subtidal, and grows on sandy, muddy and silty substrates.

<i>Zostera muelleri</i> Species of plant in the family Zosteraceae

Zostera muelleri is a southern hemisphere temperate species of seagrass native to the seacoasts of South Australia, Victoria and Tasmania. and New Zealand. Today, Zostera muelleri can be found in regions of Australia, New Zealand, and Papua New Guinea, as well as areas of the eastern Indian Ocean, and the southwest and western central Pacific Ocean. Zostera muelleri is a marine angiosperm, and is commonly referred to as eelgrass or garweed. It is a fast growing and readily colonizing species that serves as a feeding ground for wading birds and aquatic animals, and a breeding ground for juvenile fish and shrimp species.

Polly A. Penhale is an American biologist and Environmental Officer at the National Science Foundation. She is a leading figure in Antarctic research, and has been recognized for contributions to research, policy, and environmental conservation. Penhale Peak in Antarctica is named for her.

<i>Syringodium isoetifolium</i> Species of aquatic plant

Syringodium isoetifolium, commonly known as noodle seagrass, is a species of flowering plant in the family Cymodoceaceae, growing underwater in marine habitats. It forms seagrass meadows in shallow sandy or muddy locations in the Indian and Pacific Oceans.

<i>Electra posidoniae</i> Species of bryozoan (marine moss animal)

Electra posidoniae is a species of bryozoan in the family Electridae. It is endemic to the Mediterranean Sea, and is commonly known as the Neptune-grass bryozoan because it is exclusively found growing on seagrasses, usually on Neptune grass, but occasionally on eelgrass.

References

  1. ↑ Short, F.T.; Carruthers, T.J.R.; Waycott, M.; Kendrick, G.A.; Fourqurean, J.W.; Callabine, A.; Kenworthy, W.J.; Dennison, W.C. (2010). "Zostera marina". IUCN Red List of Threatened Species . 2010: e.T153538A4516675. doi: 10.2305/IUCN.UK.2010-3.RLTS.T153538A4516675.en . Retrieved 13 October 2023.
  2. ↑ den Hartog, C. (1970). The seagrasses of the world. Verh K Ned Ak Wet Adf North-Holland, Amsterdam 59: 1-275. – in Möller, T. Zostera marina (Linnaeus 1753), Eelgrass (Angiospermophyta). Archived July 17, 2011, at the Wayback Machine Helsinki Commission: Baltic Marine Environment Protection Commission.
  3. 1 2 3 4 Flora of North America
  4. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Borum J., et al., (Eds.) (2004.) European seagrasses: an introduction to monitoring and management. European Union: Monitoring & Managing of European Seagrasses.
  5. ↑ Bos AR; TJ Bouma; GLJ de Kort & Marieke M van Katwijk (2007). "Ecosystem engineering by annual intertidal seagrass beds: Sediment accretion and modification". Estuarine, Coastal and Shelf Science . 74 (1–2): 344–348. Bibcode:2007ECSS...74..344B. doi:10.1016/j.ecss.2007.04.006.
  6. 1 2 Parnell, J. and Curtis, T. 2012. Webb's An Irish Flora. Cork University Press ISBN   978-185918-4783
  7. ↑ Fonseca, M., et al. (2003). NOAA joint pilot project on eelgrass (Zostera marina L.) recovery in San Francisco Bay. Archived July 21, 2011, at the Wayback Machine NOAA National Centers for Coastal Ocean Science.
  8. 1 2 3 Wyllie-Echeverria, S. and M. Fonseca. (2003). Eelgrass (Zostera marina L.) in San Francisco Bay, California from 1920 to the present. Archived July 21, 2011, at the Wayback Machine NOAA National Centers for Coastal Ocean Science.
  9. 1 2 3 4 5 6 7 8 Hanson, A. R. (2004). Status and conservation of eelgrass (Zostera marina) in eastern Canada. Canadian Wildlife Service Technical Report Series #412.
  10. ↑ UK Marine Special Areas of Conservation
  11. ↑ Jedrzejczak, M. F. (2002). Stranded Zostera marina L. vs wrack fauna community interactions on a Baltic sandy beach (Hel, Poland): A short term pilot study, Part II. Oceanologia 44:3 367-87.
  12. ↑ Kurilenko, V. V., et al. (2010). Granulosicoccus coccoides sp. nov., isolated from leaves of seagrass (Zostera marina). Int J Syst Evol Microbiol 60 972-76.
  13. ↑ Jones, BJ; Cullen-Unsworth, LC; Unsworth, RKF (2018). "Tracking Nitrogen Source Using δ15N Reveals Human and Agricultural Drivers of Seagrass Degradation across the British Isles". Frontiers in Plant Science. 9: 133. doi: 10.3389/fpls.2018.00133 . PMC   5808166 . PMID   29467789.
  14. ↑ Bos, Arthur R & Marieke M. van Katwijk (2007). "Planting density, hydrodynamic exposure and mussel beds affect survival of transplanted intertidal eelgrass" (PDF). Marine Ecology Progress Series. 336: 121–129. Bibcode:2007MEPS..336..121B. doi: 10.3354/meps336121 .
  15. ↑ van Katwijk MM; AR Bos; VN de Jonge; LSAM Hanssen; DCR Hermus & DJ de Jong (2009). "Guidelines for seagrass restoration: Importance of habitat selection and donor population, spreading of risks, and ecosystem engineering effects". Marine Pollution Bulletin. 58 (2): 179–188. Bibcode:2009MarPB..58..179V. doi:10.1016/j.marpolbul.2008.09.028. PMID   19131078.
  16. ↑ Infantes, Eduardo; Crouzy, Caroline; Per-Olav, Moksnes (2016). "Seed Predation by the Shore Crab Carcinus maenas: A Positive Feedback Preventing Eelgrass Recovery?". PLOS ONE. 11 (12): e0168128. Bibcode:2016PLoSO..1168128I. doi: 10.1371/journal.pone.0168128 . PMC   5157998 . PMID   27977802.
  17. ↑ Olsen, Jeanine L.; Rouzé, Pierre; Verhelst, Bram; Lin, Yao-Cheng; Bayer, Till; Collen, Jonas; Dattolo, Emanuela; De Paoli, Emanuele; Dittami, Simon (2016-02-18). "The genome of the seagrass Zostera marina reveals angiosperm adaptation to the sea". Nature. 530 (7590): 331–335. Bibcode:2016Natur.530..331O. doi: 10.1038/nature16548 . hdl: 11250/2386505 . ISSN   0028-0836. PMID   26814964.
  18. 1 2 Alm, T. (2003). "On the uses of Zostera marina, mainly in Norway." Economic Botany 57:4 640-45. JSTOR   4256745
  19. ↑ Goulding, Matt (9 January 2021). "Seeding the Ocean: Inside a Michelin-Starred Chef's Revolutionary Quest to Harvest Rice From the Sea". Time. Photographs by Paolo Verzone. Retrieved 13 October 2023.
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