Sea grass is an underwater plant with characteristics of a land plant. It evolved to survive completely submerged in water. Given the enormous amount of carbon that these plants can absorb, sea grasses play a large role in removing carbon from the atmosphere. They are also considered ecosystem engineers, since they define the ecosystems that they are a part of.
Sea grasses can be identified by where they are located. Since sea grass must engage in photosynthesis in order to produce food and survive, it cannot be found too deep in water. Also, the water cannot be so cloudy that it blocks rays of sun. According to the University of Florida, sea grasses are often found in bays and lagoons in some of the warmest waters, though they are often destroyed by chemicals, such as agricultural fertilizers, that run off into the water. Sea grass has also been lost in areas of extensive fishing. As a result, it is most often found in protected lagoons and bays.
Sea Grass Versus Other Water Plants
Sea grass does not look like seaweed or most other aquatic plants because it has many of the characteristics usually only found on land plants, such as leaves, roots, conducting tissues, flowers and seeds. Some species of sea grass are sometimes confused with algae, but sea grasses have specialized structures that are not found on algae, according to the Smithsonian Marine Station. If an explorer is not sure, the sea grass can be distinguished from algae by pulling one piece of sea grass out of the ground to inspect the bottom of the sea grass for a root structure.
Sea Grass Versus Land Grass
Sea grass can be distinguished from regular grass because it does not need a strong supportive base, since it does not have to overcome gravity. Instead, it is supported by its natural buoyancy in the water, which causes it to float upward to where it is erect, with its roots anchoring it in the ground.
Sea grasses are called grasses because they grow in large meadows that resemble the meadows where they are found on land. These meadows become ecosystems in their own right. They slow down water currents, which cause the area to become more sedimented. Their roots cause the seabed to remain stable. They encourage large populations of fish to flourish nearby them because they not only serve as a source of food but also produce a very large amount of oxygen.
Sea grass has characteristics that vary depending on the species. Turtlegrass has flat blades, green and rounded tips, and leaves that are often covered with sediment. Manatee grass has thin and cylindrical blades, according to Cedar Crest College. Halodule beaudetti has very thin and flat blades. Some forms of sea grass, such as the amphibolis, grow very closely together. Other forms of sea grass, such as the cymodocea, grow more far apart.