Coral reefs are important ecosystems that are home to a large number of marine life forms, providing them with shelter and protection. It is estimated that approximately 65% of marine fish live in this important habitat, therefore, its preservation is essential.
Despite looking like a lot of rocks, coral reefs are actually formations produced mainly by a marine animal generically called coral. This animal is adapted to live in colonies and produces a calcium carbonate skeleton around you throughout your life. When these animals die, new ones appear and give rise to more skeletons. In addition to corals, other organisms can be part of the formation of reefs through the production of a limestone skeleton, as is the case with some algae.
Corals are animals of the phylum of cnidariansand live in tropical and subtropical regions of the planet. They are considered important bioindicators of water quality, since they only survive in clean and clear water, quickly responding to disturbances in the environment.
These animals live in symbiosis with some photosynthetic algae known as zooxanthellae. These algae live inside the coral and provide it with organic compounds, while the coral provides protection for them. In addition, zooxanthellae produce substances that leave corals with characteristic colors.
Corals, in addition to obtaining organic compounds through zooxanthellae, extract food from the sea. Thanks to their tentacles, these cnidarians manage to capture some beings present in marine plankton.
We can classify coral reefs into three main types: fringes, barriers and atolls. You fringe reefs they are those that form near the coast, separated from it by shallow lagoons. You barrier reefs they form parallel to the coast, but the lakes have deep waters. You atolls, in turn, present themselves as rings in the middle of the ocean and usually arise as a result of the sinking of islands.
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Coral reefs, as mentioned above, harbor a multitude of living beings, being considered one of the most diverse marine systems. This diversity is also important for the man who economically explores the reefs, especially with regard to fishing and tourism. In addition, corals act to protect the coast from the action of the sea and are important sources of raw material for the creation of medicines and cosmetics.
Unfortunately, despite all their economic and environmental importance, coral reefs are suffering irreparable damage as a result of human action. Research indicates that approximately 30% of reefs are deeply damaged. Pollution, overfishing and the increase in the average temperature of the oceans, for example, are some of the most common problems faced by this ecosystem.
The increase in temperature, increasingly accentuated by global warming, causes the process known as bleaching, which is characterized by the loss of zooxanthellae and, consequently, the color of the coral. This process makes the animal weaker and more susceptible to disease.
Curiosity: In Brazil, coral reefs are still not widely known. However, large communities are found on the northeastern coast from Bahia to Maranhão. The largest living coral reef in the world occurs in Australia and is called the Great Barrier Reef.
By Ma. Vanessa dos Santos
Would you like to reference this text in a school or academic work? Look:
SANTOS, Vanessa Sardinha dos. "Coral reefs"; Brazil School. Available in: https://brasilescola.uol.com.br/biologia/recifes-corais.htm. Accessed on June 27, 2021.
