Atolls can come in different shapes and sizes, from circular to oval, and can be hundreds of miles in circumference. Although atolls were initially thought to only exist in the Pacific Ocean, they can be found in other parts of the world such as the Indian Ocean, the Caribbean, and the Red Sea.
An atoll is a coral reef that has grown on top of a submerged volcanic island, forming a ring shape. The island sinks overtime, leaving behind only the coral ring. Atolls are found in warm, shallow waters and are made up of different types of coral, such as branching, plate, and massive corals.
The surrounding waters of an atoll are typically clear and shallow, which is why they are popular destinations for snorkelers and divers. Atolls also play an essential role in the ecosystem as they serve as a home to a diverse array of marine creatures, including fish, sea turtles, and sharks.
However, they are also sensitive to changes in water temperature and acidity caused by human activities such as pollution and climate change, which can lead to their destruction.
In summary, an atoll is a ring-shaped coral reef that grows on top of submerged volcanic islands and is a critical part of the marine ecosystem, but is also at risk from human-related damage.