This week on The Sydneyist we explore the humble Sydney Harbour oyster. We’ve all tasted Sydney’s famous rock oysters but it might shock you to learn how abundant they once were, and how dire the situation has become. These tasty morsels, a reliable food source for pre-colonial Indigenous people and for early colonists, also had two very important ecological functions - to purify harbour waters and to nurture other species. Oyster reefs, says my guest Professor Paul Gribben, are the coal reefs of the temperate region, but now they’re mostly gone. What to do? Our guest this week is Prof. Paul Gribben who leads the UNSW Centre for Marine Science and Innovation. Paul is pioneering the restoration of Sydney’s Rock Oyster Reefs. How is it done? For this question and more, join us every Thursday at 6pm on Eastside Radio, 89.7FM or streaming on eastsidefm.org