Zostera is a small genus of widely distributed
seagrassSeagrasses are flowering plants from one of four plant families , all in the order Alismatales , which grow in marine, fully-saline environments.-Ecology:These unusual marine flowering plants are called seagrasses because the leaves are long and narrow and are very...
, commonly called
marine eelgrass or (outside North America) simply
eelgrass. It contains twelve species.
Zostera is found on sandy substrates or in
estuariesAn estuary is a semi-enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries are thus subject to both marine influences, such as tides, waves, and the influx of saline water; and riverine influences, such as flows of...
submerged or partially floating. Most
Zostera are perennial. They have long, bright green, ribbon-like leaves, about 1 cm wide. Short stems grow up from extensive, white branching
rhizomeIn botany, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
s.
Zostera is a small genus of widely distributed
seagrassSeagrasses are flowering plants from one of four plant families , all in the order Alismatales , which grow in marine, fully-saline environments.-Ecology:These unusual marine flowering plants are called seagrasses because the leaves are long and narrow and are very...
, commonly called
marine eelgrass or (outside North America) simply
eelgrass. It contains twelve species.
Zostera is found on sandy substrates or in
estuariesAn estuary is a semi-enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries are thus subject to both marine influences, such as tides, waves, and the influx of saline water; and riverine influences, such as flows of...
submerged or partially floating. Most
Zostera are perennial. They have long, bright green, ribbon-like leaves, about 1 cm wide. Short stems grow up from extensive, white branching
rhizomeIn botany, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
s. The flowers are enclosed in the sheaths of the leaf bases, the fruits are bladdery and can float.
Zostera beds are important for sediment deposition, substrate stabilization, as substrate for epiphytic
algaeAlgae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms. The largest and most complex marine forms are called seaweeds. They are photosynthetic, like plants, and "simple" because they lack the many distinct organs found in...
and micro-invertebrates, and as nursery grounds for many species of economically important fish and shellfish.
Zostera often forms beds in
bay mudBay mud consists of thick deposits of soft, unconsolidated silty clay, which is saturated with water; these soil layers are situated at the bottom of certain estuaries, which are normally in temperate regions that have experienced cyclical glacial cycles...
in the estuarine setting. It is an important food for
Brent GeeseThe Brant Goose , a goose of the genus Branta, is known in North America as Brant, Brent Goose or Black Brant. The spelling "Brant" is the original one, with "Brent" being a later folk-etymological idea that it was derived from a classical Greek waterbird name brenthos...
and
WigeonThe Wigeon or Eurasian Wigeon is one of three species of wigeon in the dabbling duck genus Anas. It is common and widespread within its range...
.
The Slime mold
Labyrinthula zosterae can cause wasting disease of
Zostera, with
Z. marina being particularly susceptible, causing a decrease in the populations of the fauna that depend on
Zostera.
Eelgrass has been used for food by the
SeriThe Seris are an indigenous group of the Mexican state of Sonora. The majority reside on the Seri communal property , in the towns of Punta Chueca and El Desemboque on the mainland coast of the Gulf of California...
tribe of
Native AmericansThe indigenous peoples of the Americas are the pre-Columbian inhabitants of the Americas, their descendants, and many ethnic groups who identify with those peoples...
on the coast of
SonoraSonora is a state in northwestern Mexico with an area of 182,052 square kilometers, making it around the size of Syria. It is surrounded by the states of Baja California and the Sea of Cortez to the west, Chihuahua to the east, Sinaloa to the south, and Arizona to the north.The capital is...
,
MexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. The rhizomes and leaf-bases of eelgrass were eaten fresh or dried into cakes for winter food. It was also used for smoking
deerDeer are the ruminant mammals forming the family Cervidae. They include for example Moose, Red Deer, Reindeer, Roe and Chital. Animals from related families within the order Artiodactyla are often also considered to be deer – these include muntjac and water deer...
meat. The
Seri languageSeri is a language isolate spoken by the Seri people in two villages on the coast of Sonora, Mexico.-Classification:...
has many words related to eelgrass and eelgrass-harvesting. The month of April is called
xnoois ihaat iizax, literally "the month when the eelgrass seed is mature".
Zostera has also been used as packing material and as stuffing for mattresses and cushions.
Eel grass once grew in abundance in Barnegat Bay, NJ, where it was harvested, dried out and used for house insulation (e.g., the Governor's summer mansion in Island Beach State Park). Unfortunately, a blight decimated the eelgrass, which ended harvesting of the plant. The plant is making a gradual comeback.
Zostera is able to maintain its
turgorTurgor pressure or turgidity is the main pressure of the cell contents against the cell wall in plant cells and bacteria cells, determined by the water content of the vacuole, resulting from osmotic pressure, i.e. the hydrostatic pressure produced by a solution in a space divided by a semipermeable...
at a constant pressure in response to fluctuations in environmental osmolarity. It achieves this by losing solutes as the tide goes out and gaining solutes as the tide comes in.
Distribution
Zostera marina L. and
Zostera nana Roth have both been recorded from
Lough FoyleLough Foyle is the name given to the estuary of the River Foyle in Ulster. It starts where the Foyle leaves Derry. It separates the Inishowen Peninsula in County Donegal from Northern Ireland....
,
Northern IrelandNorthern Ireland is a part of the United Kingdom of Great Britain and Northern Ireland and it is situated in the north-east of the island of Ireland. It shares a border with the Republic of Ireland to the south and west...
.
Zostera capricorni occurs in Australia
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