Scientists discover hidden tropical oyster reefs across northern Australia

SYDNEY, May 6 (Xinhua) -- Australian researchers have uncovered extensive, previously undocumented tropical oyster reefs thriving across northern Australia, reshaping scientific understanding of coastal ecosystems, a Griffith University study said on Tuesday.

The study marks the first comprehensive mapping of these reefs, which span from Queensland's Gladstone region to the Gulf of Carpentaria and Western Australia. Some reefs stretch over five hectares and are visible via satellite imagery, said a press release from Griffith University.

Their discovery challenges long-held assumptions that oyster reefs were mainly temperate and highlights the urgent need to include them in conservation efforts, said the research lead Marina Richardson, a research fellow at Griffith's School of Environment and Science.

Oyster reefs are essential marine habitats made up of living oysters and their shells. Often called the "kidneys of the sea," they play a key role in coastal ecosystems by offering shelter for marine life, naturally filtering water, and helping to protect shorelines from erosion, according to Griffith University.

However, over 99 percent have disappeared from southern Australia, rendering them functionally extinct in those regions, according to the study published in Marine Environmental Research.

Using modern DNA tools, researchers identified the reef-building species as "Saccostrea Lineage B," a close relative of the Sydney rock oyster. Lineage B remains scientifically unnamed and was only recently reported in Queensland during a 2024 biodiversity survey, it said, adding more than 60 new reef sites have been located through a collaborative effort involving satellite technology and citizen scientists since June 2024.

"By understanding where these reefs are, how many are left and how they function, we can ensure that they're not left behind in the global restoration movement," Richardson said. Enditem