Huge coral reef discovered at Amazon river mouth

  

  A huge 3,600 sq mile (9,300 sq km) coral reef system has been found below the muddy waters off the mouth of the river Amazon, astonishing scientists, governments and oil companies who have started to explore on top of it.

The existence of the 600-mile long reef, which ranges from about 30-120m deep and stretches from French Guiana to Brazil’s Maranhão state, was not suspected because many of the world’s great rivers produce major gaps in reef systems where no corals grow.

Coral reef :

• Coral reefs are diverse underwater ecosystems held together by calcium carbonate structures secreted by corals.
•  Coral reefs are built by colonies of tiny animals found in marine waters that contain few nutrients. 
• Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. 
• The polyps belong to a group of animals known as Cnidaria, which also includes sea anemones and jellyfish. 
• Unlike sea anemones, corals secrete hard carbonate exoskeletons which support and protect the coral polyps. 
• Most reefs grow best in warm, shallow, clear, sunny and agitated waters.

Amazon River 

The Amazon River in South America is the largest river by discharge of water in the world, and the second in length.