The “rainforests” of the ocean, coral reefs are important ecosystems with high biodiveristy that makes it a great source of genetic materials. Not only are they filled with food and medicine resources, but they also protect coastlines from wave erosion.

Many animals make up parts of the coral reef. In fact, corals are animals related to jellyfish and anemones. Solitary and colonial coral feed on plankton, which are microscopic plants and animals, using arm-like tentacles to bring food to the centrally located mouth. Hard corals also host algae with which it forms a symbiotic relationship. Because of algae’s photosynthentic properties, it can provide an additional food source to the coral. Corals secrete hard, calcareous (aragonite) exoskeletons, which provide structural rigidity. The shapes colonial coral can form range from finger-shaped, brancing, or moundshaped structures that can span tens to hundreds of miles.

While coral can be found in many of the world’s oceans, the reef-forming variety can only be found in shallow, clean, tropical waters between the latitudes of the 30° north and 30° south. If the conditions are suitable, coral larvae can situate themselves on hard substances, so that they may start to grow. As reefs grow, they build upon the remains of previous colonies. Brilliant and vivid coral reefs are found along coastlines, volcanic islands, and isolated atolls.

Coral reefs primarily can be found in two distinct regions: the Wider Caribbean (Atlantic Ocean) and the Indo-Pacific (from East Africa and the Red Sea to the Central Pacific Ocean)

Coral is much more diverse in the Indo-Pacific, especially in the waters around Indonesia, the Philippines, and Papaua new Guinea. Marine fauna follow the coral trend, as they are most varied in this region as well.

The Atlantic Ocean has fewer species, but are just as unique as those found in the other regions. In fact, there are very few common species between the two regions.

Coral Science from Outer Space to Inner Space

Coral reef systems can be found surrounding approximately 100 countries. These fragile and endangered ecosystems are home to more than 25% o the world’s marine life. In the past few decades, more than 35 million acres of reef have been destroyed. When temperatures change or any other aspects of the environment change, coral reefs lose the algae cells they rely on and appear white. Depending on the duration of stress, the coral may recover, or in some cases die. If the present rate of destruction continues, 70% of the coral reefs will be destroyed in the coming decades.

Hawaii has a very unique ecosystem, and a large part of it is comprised of its beautiful coral reefs. These reefs offer so much biological diversity making them great locations for fishing and tourism, in fact, many tours like to show off these reefs. The colors of the reefs have garnered the name the “tropical rainforest of the sea.” Many creatures nestle in the reefs for food or breeding. Because Hawaii is a younger geological formation, the reefs surrounding it are also younger when compared to reefs around the world. As reefs grow and develop, they become fringing reefs, which are seen in shallow water, then become barrier reefs which have a lagoon separating it from the shore.

Hawaii’s reefs grow westward because of the islands’ westward growth. Since there are no fully developed reefs, Hawaii’s reefs are not as prolific, and mostly consist of coral due to the lack of nutrients and feeding animals. The reef lacks species such as sponges, soft coral, tunicates, and other animals found in the Great Barrier Reef. Hawaii only has 40 kinds of reefs when compared to the parts of the Pacific Ocean, which has over 300. While Hawaii’s reefs are much smaller when compared to other parts of the Pacific, its young and growingreefs still make it a popular stop while on a Hawaii tour or vacation.

Coral reefs are complex structures that depend on a variety of marine creatures. Out of the creatures that contribute to a reef’s growth, the most important are the Scleractinian corals, tiny animals that are the driving force behind most of the coral’s solid structure. Each individual creature is referred to as a polyp and has a hard shell made of calcium carbonate, which is formed from the substances extracted from the ocean. Another kind of coral, commonly known as fire coral, contribute to the reefs of the Caribbean Sea. Matured hard coral are part of groups called colonies, where the most superficial layers are made of living polyps, with each generation building on the remains of ancestors. Each polyp is genetically identical, and often grow in larger groups sometimes comprised of different species.

Plants called coralline, or calcareous algae, also contribute to the growth of coral reefs. Like the coral, they use calcium carbonate in their reef building processes. This algae grows among the coral colonies and assists in solidifying the structure.

Aside from the algae and the coral, there are other creatures, such as sponges, octocorals, and other algae that stick to the coral’s surface. All these creatures living together add another level of structural and biological complexity that makes any coral reef an exciting ecological system.