The world of corals

The Great Barrier Reef is the largest coral reef system in the world visible from space.

Corals, the beautiful plantlike structures in the sea floor, are actually hundreds to thousands of tiny creatures called polyps. Soft polyp secretes a hard skeleton of limestone that attaches itself to other sea structures like rock or dead skeletons of other polyps. Polyps live in colonies and grow connected to each other. They are dependent on one another for survival.

 

Most coral reefs are found in the warm shallow waters of tropics and subtropics. About 90 percent of the world’s coral reefs occur in the Indo-West Pacific region. Some Reef systems also exist in the West and East Atlantic, and East Pacific oceans between 30° N and 30° S. Major Reef systems are recognised on the basis of their location like Caribbean reefs; the Great Barrier Reef; the Red Sea; Arabian Sea; and Persian Gulf reefs.

                                                     Distribution of the world's coral reefs                                    Cartographer: Hugo Ahlenius

 

Out of them, The Great Barrier Reef is the most well-known. It’s the largest coral reef system in the world, extending 2,300 kilometers from the Torres Strait, just south of Papua New Guinea down the eastern coast of Australia. It is the world’s largest structure built from living organisms visible from space.

Coral reefs are among the most complex and fascinating marine ecosystems in the seas and are home to the planet’s most diverse habitats. That's why they are sometimes known as the “rainforests of the sea.” Nearly a quarter of all the fish in the sea and many other organisms rely on healthy coral reefs. 

Coral reefs are known as the “rainforests of the sea.” as they are habitat for fishes and  many other organisms.

 

The Northwest Hawaiian Island coral reefs are home to about seven thousand species of plants and animals. They are not only home to many marine species, but they are a source of livelihood for many local communities. Millions of people around the world rely on fish caught in and around coral reefs. 

 

Corals are a source of livelihood for many local communities.

The reefs also draw in tourists, which helps the local economies. Coral reefs protect people and land from storms as well, serving as a barrier that reduces the impact of large waves on shore. 

However, they’re increasingly threatened from pollution, increasing ocean temperatures, overfishing, water pollution, coral bleaching and ocean acidification. Coral reef systems are most sensitive to pollution and increasing ocean temperatures and this can adversely affect humans and marine species alike. It results in coral bleaching where stressed corals expel their symbiotic algae causing them to turn white. The absence of the zooxanthellae in ocean waters causes the coral to have limited food supply and they become more susceptible to diseases.

Corals are under severe threat from pollution, increasing ocean temperatures, overfishing, water pollution, coral bleaching and ocean acidification.

 

Recent research shows that the world has already lost nearly 20 percent of its coral reefs and many more reefs are under severe threat. It is now needed that preventive and mitigating steps are taken to prevent further deterioration of coral reefs and their extinction.

Reference -

Distribution of the world's coral reefs, 2010, Cartographer: Hugo Ahlenius, Available at -https://www.grida.no/resources/7765

Images form Pixabay