What is seagrass?
Seagrasses are a type of submerged aquatic vegetation (SAV) have evolved from terrestrial plants and have become specialized to live in the marine environment. Like terrestrial plants, seagrasses have leaves, roots, conducting tissues, flowers and seeds, and manufacture their own food via photosynthesis. Unlike terrestrial plants, however, seagrasses do not possess the strong, supportive stems and trunks required to overcome the force of gravity on land. Rather, seagrass blades are supported by the natural buoyancy of water, remaining flexible when exposed to waves and currents. Due to their morphology and growth habit, seagrasses are also sometimes confused with marine macroalgae; however closer examination reveals significant differences. Structurally, seagrasses are more closely related to terrestrial plants and, like terrestrial plants, possess specialized tissues that perform specific tasks within each plant. Conversely, algae are relatively simple and unspecialized in structure.
• Seagrasses are not “true” grasses • Seagrasses are found in shallow coastal waters • Seagrasses provide important habitat for marine organisms Seagrasses are more closely related to the lilies rather than true grasses. There are over 50 temperate and tropical species of seagrass belonging to two families, with the most diversity occurring in the Indo-West Pacific region. Seagrasses are found on the bottom of protected bays, lagoons, and other shallow coastal waters. Although they are not true grasses, seagrasses appear grass-like with shoots of three to five leaf blades attached to a horizontal stem. They are attached to the bottom by thick roots and rhizomes, allowing seagrasses to live in areas with wave action and strong currents. Seagrasses can form large underwater meadows, spreading through the extension of the rhizome that produces new plants along the edges of the meadow. Flowering also occurs, producing seeds that are quickly dispersed via currents and tides. Sea Urchin © Do
There are about 50 species of “true seagrasses” found throughout the world, and they are found within four plant families (Posidoniaceae, Zosteraceae, Hydrocharitaceae, or Cymodoceaceae). As a whole, they are not closely related, but they share characteristics associated with adapting to the marine environment. Most seagrasses live completely submerged on sandy or muddy sediments, but some species can tolerate exposure at low tide and some are capable of growing over rock. They require a very significant amount of light (15-25% surface irradiance, compared to <3% for other aquatic primary producers), which limits the depths at which they can occur. Some survive at over 40 meters in depth in clear ocean water. Here on Long Island, and throughout the northeast Atlantic, we only have one representative species that is considered a true seagrass; Zostera marina a.k.a. eelgrass. View Word Document "Seagrasses of the World" There are other aquatic plants that are sometimes grouped with seagr
Seagrass plants are fast-growing perennials that thrive in wet environments. Merida’s carpets and rugs are made from the resilient, flexible stems of seagrass plants. Seagrass is known for retaining its fresh, grassy scent long after it has left the field, but this will dissipate in time. When seagrass is woven into a carpet, the result is a highly spill-resistant, durable, resilient floor covering that is comfortable underfoot and retains the fresh look of the outdoors.
