Coral Reefs

Coral reefs are rocky formations created in marine areas by living organisms such as polyps and algae through the secretion and deposition of limestone over stony corals.

Coral reefs are built and grow over centuries into large and diverse coral reef ecosystems creating a complex habitat of aquatic plants, corals, fish and other marine species. They are sometimes referred to as "rainforests" of the sea.

Coral reefs can be found all over the world, although a majority of them exist in tropical zones.

Corals fringing the coast are a common sight but barrier reefs are largest and most impressive are of them. Barrier reefs are like large, continuous mountain ranges, separated from land by lagoons.

Australia's 2,000 km long Great Barrier Reef is visible from outer space
Image courtesy NASA/GSFC/LaRC/JPL, MISR Team

 

Water and Life: Acquatic Ecosystems

As a source of life, water sustains an immense variety of life around and within it on Earth. 

Water based ecosystems are called aquatic ecosystems.

Saltwater and freshwater support entirely different ecosystems. There are multiple types of acquatic ecosystems on Earth.

Marine Ecosystems present in 71% of Earth's salwater i.e. oceans and sea.

Colorful underwater landscape of a coral reef

Freshwater Ecosystems which have different variations depending on the type, flow and presence of water in the ground.

River Ecosystems in flowing rivers and water bodies.





Salmon fish in river

Lake Ecosystems in lakes, ponds and other contained water bodies.

 

Tundra swans in a lake with mt shasta in the background

Wetlands created by seasonal or permanent saturation of water in and around the ground.

 

Flooded Wetlands