The are three main types of tropical coastal marine ecosystem:

• Coral Reefs
• Sea-grass Beds
• Mangrove Habitats 

CORAL REEFS
Coral reefs are a community of many different marine plants and animals, both living and dead. The first reefs developed about 400 million years ago, but modern reef have only existed for some 5 million years. The physical structure of the reef is mainly made of limestone from hard coral skeletons; however the remains of other organisms that contain calcium carbonate material also adds to the reef structure (such as shells of clams, and forms). Over time, broken bits of coral skeleton and calcium carbonate material are cemented together by a type of red coralline algae and by magnesium calcite particles found in the sea water. 

The reefs of Komodo National Park are an important habitat for about 1000 species of fishes, over 250 species of reef-building corals, and at least 105 species of crustaceans and 70 species of sponges. Coral reefs are also important for shore-line protection and are source of pharmaceutical compounds such as anti-cancer agents.

Type of Coral Reefs
FRINGING REEFS, TAKA & SEAMOUNTS, BARRIER REEFS & PATCH REEFS

SEA-GRASS BEDS
Sea-grass beds are usually found in calm, shallow water, between the shore and a coral reef. They are made up of seagrasses, which are a type of flowering plant. Sea grasses are an important shelter for many young fish and invertebrates. Many animals eat sea grass such as turtles, dugongs, molluses and urchins.

MANGROVES
Mangroves are a natural physical barrier against soil erosion and they also provide a unique eco system. The arial roots are an important breeding ground, nursery and shelter for juvenille fish and shrimp. Mangroves also provide habitat for crabs, molluses, estuarine crocodiles and provide rooting/nesting grounds for many seabirds. Traditionally, mangroves are a source of firewood, building materials, tannin, dyes, medicine and fruit for local communities.

MARINE PLANTS
Marina Plants include algae, sea-grasses, and mangroves. Plants are an important food source or habitat for many different reef animals. Marine plants, like land plants, require sunlight and carbon dioxide to produce food for their survival.

MANGROVES 
Mangroves are a special tree that can live in salty soil or water. Part of the mangrove root is above the water so that it can take carbon dioxide from the air. Some mangroves have seeds that float in the sea until they find suitable ground to grow on. Other mangroves have long pods which germinate on the tree and then drop into the mud below the parent tree. Komodo National Park has 18 different kinds of mangrove trees.

FORAMS 
Simple reef-building protozoans (tiny plant - like animals) that are often overlooked. They are made up of a blob of jelly with a hard calcium carbonate shell. The shell is covered in protoplasm which can be expanded and contracted for slow locomotion. The protoplasm is able to feed on microscopic organisms, expel waste and exchange gases. Some forams can float in the water, others are anchored to the reef. Broken forams shells make a large portion of coral sand and limestone.

SEAGRASS (SEAWEED)
Seagrasses are a modern plant that produce flowers, fruits and seeds for reproduction. As their name suggests, they generally look like large blades of grass growing underwater in sand near the shore.