Posidonia australis, a seagrass found in Shark Bay, Western Australia, holds the title of the largest single living organism on Earth, spanning nearly 200 square kilometers. This colossal seagrass meadow stretches 112 miles in length and intriguingly, is genetically identical throughout, as revealed by rigorous genetic testing. The astounding age of the giant marine plant is estimated to be around 4,500 years, based on the growth rate of seagrasses and the age of Shark Bay. This age also places it among the oldest living organisms known to us.  Beyond its sheer size and age, Posidonia australis has an enormous ecological … Continue reading Earth’s Largest Single Organism: Understanding Underwater Giant Posidonia australis, Guarding Earth’s Oceans