Coral reefs are a unique marine biome. Sadly, they are very vulnerable to destructive human activity and global climate change.
Locations of coral reef biome
Coral reef biomes are found only in warm waters. Microscopic organisms of which it consists cannot live in cold water. Reefs can be found near the equator, mainly around the coastline of continents and islands. There are a lot of them in Southeast Asia, for example.
The coral reef biome is endangered
Reefs are very sensitive to the purity of water and to water temperature. If the average water temperature increases by just 1 degree, they will die – not all at once but slowly and inevitably. Also, the water pollution caused by humans is also a great threat to them. About 50% of all reefs have died within the last 50 years, and the main reason for this tragedy is water pollution. The coral reefs’ extinction would have a great negative effect on the ocean’s ecosystem in general.
Coral reefs are ancient
It is known that the first coral reefs were formed about 240 million years ago, which makes them much older than dinosaurs. If the pollution of the world’s oceans doesn’t stop, coral reefs may completely disappear by 2050.
Life of the coral reef biome
The coral reef biome is the Coral reefs have the greatest biodiversity ever! They occupy only about 0,1% of the ocean’s area but they are home to more than 25% of all known marine species on Earth. There are more than 1 million species and we can be sure that there are more, we just haven’t discovered them yet.
Reefs are a complex ecosystem
Coral reefs are the most complex ecosystem on Earth. The mucus secreted by corals serves as a breeding ground for bacterial plankton, which envelops the reefs in clouds of organic suspension. Zooplankton and benthic invertebrates eat it. Fish feeds on zooplankton. That’s a food chain, and we’re on top of it because we eat fish and other seafood.
500 million people are living off coral reefs
Of course, the coral reef biome is super important for the world’s ecosystem. However, it’s even more important for a huge number of people – about half a billion of them, give or take. The annual value of ecosystem services provided by coral reefs around the world is estimated at $375 billion! They give 500 million people from more than 100 countries (mostly fishermen and people involved in the tourism industry) an opportunity to earn.
The largest object on Earth
The Great Barrier reef near Australia is the largest object on earth, it’s 1400 miles (2300 km) long. It was even larger in the recent past, but 30% of it died in 2014-2017. The Great Barrier Reef is composed of 900+ islands and 2900+ individual reefs. There are 1500 species of fish and 400 species of coral that live on the Great Barrier Reef alone.
Coral reef biome growth
Everyone knows that reefs are growing really slowly. That’s true but only partly: some coral species grow relatively quickly, up to 4 inches (10 cm) per year. However, their average growth speed is about 1 inch per year. Some species grow just 1-2 millimeters per year.
Reefs need to eat
Coral reefs are made of polyps, and these polyps need food. They feed on small animals called plankton, as well as algae, although algae get their food from the sun through photosynthesis. That’s why coral reefs form close to the water surface and in clear water where the sun can nourish algae.
Coral reef biome types
There are 3 different types of reefs: fringe, barrier, and atoll. First ones grow close to the shore and can be attached to it, they often form lagoons. Barrier reefs grow further from the coastline. Atolls start growing around volcanic islands which sink into the ocean eventually. Millions of people live on atolls! For example, the whole country of Maldives is composed of numerous atolls.
The coral reef biome has zones
Each coral reef can be divided into 3 separate zones: inner zone, crest reef zone, and outer zone. Each of them is inhabited by different species of corals, plants, and animals. The outer part of the reef is usually the most populated.
Corals can look different
Different species of polyps form different shapes of individual corals. Some of them resemble trees, some other look like a rug or mushrooms, and some other looks like something extraterrestrial. That’s really cool!
Colorless corals are dying
Losing the color is the first sign of a bad condition of a coral reef. Sometimes corals turn white if the water is too warm, too cold, too polluted, or too salty. The white color of the coral reef means it’s dying, and will likely die soon if conditions don’t change.
The first coral reefs on Earth
The first reef-forming organisms on Earth were photosynthetic cyanobacteria that lived about 3.5 billion years ago. Corals have been found in fossil reefs up to 500 million years old.
Never touch the coral
Reefs look solid but they are extremely vulnerable. If you’re diving, please don’t touch them! Even a gentle touch can damage or even kill a coral. Also, the simplest way to contribute to the coral reef biome saving is by reducing water usage. Everyone can do that! Just turn off the tap while brushing your teeth.