Types of Reefs

• There are three basic types of coral reefs. Fringing reefs are directly attached to the shoreline of a landmass. Fringing reefs are the most common type of reef found, because they are considered relatively young. Barrier reefs are separated from land by a deep lagoon, and grow parallel to the shoreline. Atoll reefs form around an island that is completely submerged under sea-level. Atoll coral reefs continue to grow upward from the submerged island. According to the NOAA, depending on their size, barrier reefs and atolls can take from 100,000 to 30 million years to fully form.
  
  

Shoreline Damage and Erosion

• Waves from the ocean crash onto the shore and over time erode the shoreline. Coral reefs that border land act as a buffer for the harsh waves. The reefs cause the waves to slow down or stop them completely. This prevents erosion of the shoreline and potential property damage. Reefs not only protect the shoreline but also ports and harbors. The NOAA estimates that half a billion people are estimated to live within 100 kilometers of a coral reef and benefit from its production and protection.
  
  

Biological Diversity

• Coral reefs are some of the oldest ecosystems on the planet. Reefs are home to millions of species, including many that have yet to be discovered. According to the NOAA, coral reefs support more species per unit area than any other marine environment, including about 4,000 species of fish, 800 species of hard corals and hundreds of other species. From plants to fish to microorganisms, coral reefs harbor creatures from all wakes of life.
  
  

Breeding Grounds and Shelter

• Because of the vast biological diversity, it is no surprise that reefs are a popular site for breeding. Some species that do not even live in the reef may travel to that reef just to breed. Not only do coral reefs satisfy the need for plant and animal reproduction, they also provide many organisms with food and shelter. Reproduction, food and shelter are the basic needs of most organisms and coral reefs fulfill this need and then some.
  
  

Ecological Integrity

• According to the Guide to Protecting Coral Reefs, while coral reefs are sensitive to environmental changes, they appear to be able to recover effectively from physical disturbance or temporary pollution events provided that water quality is generally high. This means that even when faced with a change in the environment, coral reefs are generally resilient and have a high probability of recovering. The vast number of life forms living in coral reefs provide help keeping many unwanted environmental changes from happening. A simple example is the growth of algae. While some algae is important, too much of it can be a problem. However, there are many fish and invertebrates that live in coral reefs that eat the algae, therefore maintaining the ecosystem's balance.