Seagrass in the context of "Marine ecosystem"

⭐ In the context of marine ecosystems, seagrass meadows are best categorized as which type of zone?

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⭐ Core Definition: Seagrass

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 (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the order Alismatales (in the clade of monocotyledons). Seagrasses evolved from terrestrial plants which recolonised the ocean 70 to 100 million years ago.

The name seagrass stems from the many species with long and narrow leaves, which grow by rhizome extension and often spread across large "meadows" resembling grassland; many species superficially resemble terrestrial grasses of the family Poaceae.

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👉 Seagrass in the context of Marine ecosystem

Marine ecosystems are the largest of Earth's aquatic ecosystems and exist in waters that have a high salt content. These systems contrast with freshwater ecosystems, which have a lower salt content. Marine waters cover more than 70% of the surface of the Earth and account for more than 97% of Earth's water supply and 90% of habitable space on Earth. Seawater has an average salinity of 35 parts per thousand of water. Actual salinity varies among different marine ecosystems. Marine ecosystems can be divided into many zones depending upon water depth and shoreline features. The oceanic zone is the vast open part of the ocean where animals such as whales, sharks, and tuna live. The benthic zone consists of substrates below water where many invertebrates live. The intertidal zone is the area between high and low tides. Other near-shore (neritic) zones can include mudflats, seagrass meadows, mangroves, rocky intertidal systems, salt marshes, coral reefs, kelp forests and lagoons. In the deep water, hydrothermal vents may occur where chemosynthetic sulfur bacteria form the base of the food web.

Marine ecosystems are characterized by the biological community of organisms that they are associated with and their physical environment. Classes of organisms found in marine ecosystems include brown algae, dinoflagellates, corals, cephalopods, echinoderms, and sharks.

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Seagrass in the context of Nursery habitat

In marine environments, a nursery habitat is a subset of all habitats where juveniles of a species occur, having a greater level of productivity per unit area than other juvenile habitats (Beck et al. 2001). Mangroves, salt marshes and seagrass are typical nursery habitats for a range of marine species. Some species will use nonvegetated sites, such as the yellow-eyed mullet, blue sprat and flounder.

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Seagrass in the context of Miskito Cays

The Miskito Cays (Spanish: Cayos Miskitos) are an archipelago of small cays and reefs with an area of 27 km located off Mosquito Coast in the Caribbean exclusive economic zones of Honduras and Nicaragua. They are part of the Gracias a Dios Department in Honduras and the North Caribbean Coast Autonomous Region in Nicaragua. The Miskito Cays are composed of 76 formations that include estuaries, coral reefs, cays, seagrass beds, and islets, of which 12 of the formations are covered with vegetation and consequently form islands which are lined with white sand beaches.

In Nicaragua, the Miskito Cay (Cayo Miskito), also known as Cayo Mayor, is the largest and most important cay located in the center of the archipelago measuring 37 km. Other main islands are Maras Cay, Nasa Cay, and Morrison Denis Cay. The Miskito Cays Biological Reserve is one of 78 protected areas of Nicaragua, it was declared a protected area in 1991. The cays, along with a stretch of the adjacent mainland coast, have been designated an Important Bird Area (IBA) by BirdLife International.

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Seagrass in the context of Carbon sink

A carbon sink is a natural or artificial carbon sequestration process that "removes a greenhouse gas, an aerosol or a precursor of a greenhouse gas from the atmosphere". These sinks form an important part of the natural carbon cycle. An overarching term is carbon pool, which is all the places where carbon on Earth can be, i.e. the atmosphere, oceans, soil, florae, fossil fuel reservoirs and so forth. A carbon sink is a type of carbon pool that has the capability to take up more carbon from the atmosphere than it releases.

Globally, the two most important carbon sinks are vegetation and the ocean. Soil is an important carbon storage medium. Much of the organic carbon retained in the soil of agricultural areas has been depleted due to intensive farming. Blue carbon designates carbon that is fixed via certain marine ecosystems. Coastal blue carbon includes mangroves, salt marshes and seagrasses. These make up a majority of ocean plant life and store large quantities of carbon. Deep blue carbon is located in international waters and includes carbon contained in "continental shelf waters, deep-sea waters and the sea floor beneath them".

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Seagrass in the context of Dugong

The dugong (/ˈd(j)ɡɒŋ/; Dugong dugon) is a marine mammal. It is one of four living species of the order Sirenia, which also includes three species of manatees. It is the only living representative of the once-diverse family Dugongidae; its closest modern relative, Steller's sea cow (Hydrodamalis gigas), was hunted to extinction in the 18th century.

The dugong is the only sirenian in its range, which spans the waters of some 40 countries and territories throughout the Indo-West Pacific. The dugong is largely dependent on seagrass communities for subsistence and is thus restricted to the coastal habitats that support seagrass meadows, with the largest dugong concentrations typically occurring in wide, shallow, protected areas, such as bays, mangrove channels, the waters of large inshore islands, and inter-reefal waters. The northern waters of Australia between Shark Bay and Moreton Bay are believed to be the dugong's contemporary stronghold.

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Seagrass in the context of Giant cuttlefish

The giant cuttlefish (Ascarosepion apama), also known as the Australian giant cuttlefish, is the world's largest cuttlefish species, growing to 50 cm (20 in) in mantle length and up to 100 cm (39 in) in total length (that is, including outstretched tentacles). They can weigh over 10.5 kg (23 lb). Like all cuttlefish species, the giant cuttlefish has eight arms and two feeding tentacles, as well as blue blood and three hearts. Using cells known as chromatophores, the cuttlefish can put on spectacular displays, changing colour in an instant. The giant cuttlefish is native to temperate and subtropical waters of Australia, from Brisbane in Queensland to Shark Bay in Western Australia and Tasmania to the south. It occurs on rocky reefs, seagrass beds, and sand and mud seafloor to a depth of 100 m (330 ft). The genetically distinct population in the Upper Spencer Gulf is the most studied population, and has become a tourist attraction.

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