southeast Queensland
Noosa River Estuary southeast Queensland © Craig Bohm/TNC

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The surprising history of Queensland's oyster reefs revealed

Fresh research shows native rock oyster reefs once stretched along the southeast Queensland coast for 400 kilometres from Maryborough to Coolangatta. Hundreds of reefs as big as Brisbane’s Suncorp Stadium were common in bays and estuaries from Fraser Island to Moreton Bay and south to the NSW border. Today they’re all gone!

Co-author of the study published in Global Environmental Change today, Oceans Lead at The Nature Conservancy, Dr Chris Gillies said: “ These reefs were once a common and important part of the coastal environment of southeast Queensland. They provided homes for a diverse range of marine species, filtered seawater, provided fish nursery grounds and protected shorelines from erosion.”

“These reefs were sustainably harvested by Aboriginal people of the area, such as the Kabi Kabi people, for thousands of years. Aboriginal people also practiced an early form of oyster aquaculture and management  in shallow areas to attract oysters and fish,” said Fred Palin, Co-author and Joondoburri/Kabi Elder.

“Our research found evidence of a number of substantial Indigenous oyster middens[1] in southeast Queensland, including some as large as 65 kilometres long,” added Dr Ruth Thurstan, Lead Author from the University of Exeter. “None of these middens persist today.”

Early European settlers quickly exploited the oyster reefs (and shell middens) which were harvested for food and lime. By the 1870s a significant commercial oyster trade had developed, with oysters being sent by sailboat to markets in Sydney, Melbourne and as far away as Perth. At its peak, 44 million oysters were harvested from southeast Queensland in 1891. Because of this unsustainably high level of exploitation along with excessive siltation (caused by land clearing) and the increased prevalence of disease and oyster pests, the industry began to decline by the early 1900s. It had essentially collapsed by the 1960s.

Today the Queensland oyster aquaculture industry produces around 2 million oysters each year (worth less than $1 million) – a reduction of 96% compared to the historical peak harvest - and no longer harvests wild oysters.

We now have the opportunity to restore oyster reefs to bring back the benefits they bring like more fish, improved water quality and coastal protection, particularly important in the face of climate change and the associated need for greater coastal resilience. Restoration could also recover ‘oyster jobs’ particularly for Indigenous Australians.

“Just like we’re doing elsewhere around Australia, we’ve made a start in southeast Queensland with an oyster reef restoration project now underway in Noosa,” concluded Gillies. “We call on the Queensland Government and the Queensland community to support efforts to protect and restore these important ecosystems.”

[1] Middens are the beachside remnants of oyster harvesting by Indigenous people over thousands of years.

The Nature Conservancy is a global conservation organisation dedicated to conserving the lands and waters on which all life depends. Guided by science, we focus on getting things done efficiently and with the greatest positive impact for conservation. We’re a trusted organisation working in 70 countries around the world on innovative solutions to our world’s toughest challenges so that nature and people can thrive together. To learn more about The Nature Conservancy in Australia, follow us on Facebook.