Plants:
![Picture](/uploads/2/9/1/8/29184025/1400473229.jpg)
Sea Grass- A sea grass bed begins with the sprouting of a pioneer species like shoal grass, with flat, thin leaves; or long and threadlike manatee grass. The pioneer grass eventually gives way to turtle grass, the climax species, which has flat, straplike blades up to two feet long. Of the various species of sea grass identified off Central America, turtle grass is the most common. Like others, it is a flowering plant, having solved the problem of pollination underwater and having mastered submarine dispersal of fruit, which simply detaches and tumbles away on the current. Bright schools of small fish hang over the undersea prairie as the current stirs in the grass. Occasionally, adult parrotfish and surgeonfish come in from the reef to feed on the grass itself.
![Picture](/uploads/2/9/1/8/29184025/1400713848.jpg)
Algae- Zooxanthellae is a photosynthetic algae that lives in the coral's tissues. The corals and algae have a mutualistic relationship. The coral provides the algae with a protected environment and compounds they need for photosynthesis. In return, the algae produce oxygen and help the coral to remove wastes. Most importantly, zooxanthellae supply the coral with glucose, glycerol, and amino acids, which are the products of photosynthesis. The coral uses these products to make proteins, fats, and carbohydrates, and produce calcium carbonate. In addition to providing corals with essential nutrients, zooxanthellae are responsible for the unique and beautiful colors of many stony corals.
![Picture](/uploads/2/9/1/8/29184025/793688.jpg?309)
Mangroves- Mesoamerican mangroves form multiple lines of defense for the reef system. Along the shores, mangroves provide habitat for fish and shorebirds as well as protect coastal areas from the damage associated with hurricanes and strong storms. Mangroves are a unique group of large shrub-like plants that grow in thick, physically complex "forests" that line many tropical and sub-tropical shores. The mangroves, in addition to defense, provide mulch. They can shed tons of leaves per acre every year. Fungi and bacteria break down this leaf litter and consume it, then are consumed by tiny worms and crustaceans, which in turn feed small fish, which feed larger fish.
Why do these types of plants require this type of biome?
The turtle-grass rhizomes, or underground stems, creep horizontally under the sand and are anchored by an extensive root system. Like the mangroves, they trap silt that might otherwise settle on corals. This is a vital service. Reefbuilding corals require clear water. The basic unit of a coral colony, the tiny coral animal (polyp) produces most of its food through photosynthesis by algae resident in its tissues. Sedimentation, which screens out sunlight and kills polyps, is one of the principal causes of coral reef decline worldwide. De-sedimentation by sea grass is a given service. Turtle grass thrives in calm waters protected from surf and wind-driven currents by the barrier reef; its isolating of sediments is merely a return of the favor. Just as the coral polyp lives in internal symbiosis with its resident algae, the coral reef lives in external symbiosis with sea grass.