For 3.5 billion years long before trees existed, our photosynthesizing Stromatolites pumped oxygen into the ocean like underwater trees. When the oceans were saturated, oxygen was released into the air enabling life to flourish & evolve. Hamelin Pool, within the World Heritage listed area of Shark Bay, Western Australia, is home to the most extensive living Stromatolite system in the world. Seagrass meadows form a barrier between Hamelin Pool and the rest of the ocean protecting the Stromatolites in their hypersaline waters - long may they continue!