What are the stromatolites at Hamelin Pool?
The stromatolites at Hamelin Pool, in Shark Bay, Western Australia, are living rock-like structures built by microbes. They are among the best examples of living stromatolites in the world and resemble some of the earliest forms of life on Earth.
Stromatolites are formed by layers of cyanobacteria, microscopic organisms that trap sediment and produce calcium carbonate. Over thousands of years, these layers build up into rounded structures.
The stromatolites at Hamelin Pool are about 2,000 to 3,000 years old, but similar structures in the fossil record date back more than three billion years.
Why Hamelin Pool?
Hamelin Pool is extremely salty, about twice as salty as normal seawater. The high salinity limits animals that would normally graze on the microbes, allowing stromatolites to grow.
A boardwalk lets visitors view the stromatolites without damaging them. At low tide, they are exposed, and their dome shapes are easy to see.
Hamelin Pool is part of the Shark Bay World Heritage Area. Stromatolites helped produce oxygen in Earth's early atmosphere, making them important to the history of life on our planet.