Australian Seagrass Meadow Claims The Title Of The World's Largest Organism
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A sprawling seagrass meadow has just been declared the "world's largest single living organism" based on area. The Poseidon’s ribbon weed seagrass (Posidonia australis) is located in Shark Bay, a protected body of shallow water in Western Australia. It covers an impressive 77 square miles (200 square kilometers) — the equivalent of about 280 soccer fields! The record was previously held by a 3.7 square-mile mushroom, dubbed "Humongous Fungus," in the Malheur National Forest in Oregon, USA.
Based on its size and growth rate, the researchers estimate that the meadow is 4,500 years old. While that is ancient, it is not record-breaking. A Posidonia oceanica seagrass plant in the western Mediterranean, which covers about 9.3 miles (15 kilometers), is believed to be over 100,000 years old!
Researchers from the University of Western Australia and Flinders University stumbled upon the plant accidentally, while investigating the genetic diversity of Shark Bay's ribbon weed seagrass. The team analyzed seagrass specimens from ten meadows across Shark Bay, where the salt levels ranged from normal ocean salinity to almost twice as salty. To their surprise, they found the samples were genetically identical— meaning they all belonged to one plant. Further analysis showed that the seagrass originated from a single seedling. It grew by copying, or cloning, itself through an underground network of branching roots.

The massive plant also has another unique quality. Most seagrasses inherit half of each parent's DNA. However, the Shark Bay seagrass is a polyploid — a plant that carries the entire genome of each parent. "Polyploid plants often reside in places with extreme environmental conditions, are often sterile, but can continue to grow if left undisturbed, and this giant seagrass has done just that," Dr. Elizabeth Sinclair, the study's senior author, explained.
The scientists, who published their findings in the journal Proceedings of the Royal Society B on May 31, 2022, now plan to conduct experiments to determine how the seagrass continues to flourish in Shark Bay's harsh and varied environment.
Resources: the conversation.com, uwa.edu.au, Livescience.com

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19 Comments
- menziess100about 19 hoursThat’s beautiful 😻
- kemme071 dayThey are lucky to have many "see"grass. I wonder what they are gonna use!🤗🤗
- bsc2 daysso cool!
- hewoilikenewz3 daysWow!!!
- totyvora-1564149920563 dayshuh interesting...
- funucuhymole4 daysamazing
- iheartpuppies5 daysThis remixes me of a whole forest MADE OF ONE TREE!!!! They are all connected be roots and clones of the very first tree. Sadly, its dying out.
- sakura_blossom6 dayssuper cool
- diva-b3th4ny7 daysWoah! I would admire to see the meadow of this Australian seagrass! Isn’t it about 280 soccer fields and that is equivalent to 414 000 rugby fields! #Oceanscene #Seagrass
- iloveanimals1017 dayscool I would love to see that sea meadow it looks like i would get lost in it though #Maze #OceanScene