The world's coral reefs consist either hard coral or soft coral. They are offer the most biologically diverse ecosystems in the world. The plants help form part of the food chain that helps the coral grow.
Algae :
Marine algae are tiny plants. They do not contain roots, stems or true leaves. Algae provides a source of food for smaller fish and invertebrate sea life. Australia's Great Barrier Reef includes 500 species of marine algae, including blue-green algae, known as [cyanobacteria] , that forms red, green, purple or brown tufts on the reef. Red algae forms hard crusts on the Great Barrier Reef, helping to enlarge the reef. Other types of red algae appear much larger in the form of bushy seaweeds. Sea lettuce and sea grapes are common types of green algae that thrive on the reef.
Green algae:
Green algae are most common in shallow reef areas. These seaweeds are often found on rocky reef surfaces. Among the more abundant types of green algae common in coral reef systems are members of the genera.
Red algae:
They are really close relatives of the green algae. These forms may be found from the shallowest reef flats to depths exceeding 150 feet. Some forms of red algae are common to deeper waters of the reef ecosystem, where their specialized pigments allow them to capture the little sunlight available.
Brown algae:
Brown algae are now known to be as different from the red and green algae as they are from animals. Members of this group are not uncommon on coral reefs. Brown algae typically reach greatest abundance and diversity at intermediate depths of 30 to 70 feet.
Sea grass :
Most sea grass appears in underwater meadows that grow in a shallow and protected waters of nearby lagoons, also known as back reefs. Back reefs are located between the coral reef and the shore and are primarily found in sheltered waters or near estuaries. The grasses play an important role in supporting the sea life that uses the coral reefs. The fast growing sea grass helps trap sediment loads near coral reefs. The grass also provides habitat for small fish, invertebrate animals, sea turtles and manatees. They are the only type of angiosperm [flowering plant] to successfully colonize the sea.
Mangroves :
Mangroves make up the third type of plant growing near reefs. The plants help support a wide range of reef fishes and other marine life that use the coral reefs. More than 50 species of mangroves exist in the world. Mangrove forests primarily consist of large shrubs that grow along the shores of the back reef. The roots of the mangrove trees act as a nursery for young reef fishes. Florida's boasts about 469,000 acres of mangrove forests with many of them found along the state's southern coast. One of the rare terrestrial plants able to tolerate direct immersion in sea water, mangroves have adapted to saline conditions where other "land plants" cannot survive. They accomplish this feat by means of specialized salt-filtering roots and salt-excreting leaves. Mangroves have the capacity to considerably enhance the abundance and diversity of reef fishes and other types of marine life throughout the coral reef ecosystem. Mangroves are also instrumental in the building of new shorelines and small islands within coral reef lagoons.
Seaweeds :
Large multicellular forms of marine algae are commonly called "seaweeds". Sea weeds are widely distributed within coral reef ecosystems, where they occur as one of three main types based on color: green, red, and brown. Each of these three types of sea weeds contain photosynthetic pigments specialized to best utilize sunlight at different depths.
Flowering Plants:
Mangroves and sea grasses are two the only two types of flowering plants (angiosperms) that are often closely associated with coral reefs. Both groups are capable of rapid growth and high production rates. By trapping suspended sediments and slowing water movement these plants also benefit nearby coral reefs by reducing sediment loads in the water.
Corals:
Corals belong to a group of invertebrate animals called cnidarians. Cnidarians are characterized by a circular body enclosing a simple gut surrounded by tentacles.
Stony corals:
Stony corals occur in great diversity about 500 to 600 Caribbean species and ten times that number in the Indo Pacific region. Stony coral generally are one of the three basic growth forms, called massive, branching, or plate like.
Octo corals:
Octo corals are also commonly called "gorgonian" or "soft corals". This group includes familiar reef creatures as sea fans, sea rods, and sea whips.
Hydro corals:
Fire Corals are hydro corals. Fire corals are most common in shallow waters, particularly on lagoon patch reefs and on reef flats or crests. Fire coral colonies take many forms, they may be encrusting, plate like or highly branched. They are commonly light colored, often tan to yellow.
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