The Manning Shelf marine bioregion extends from Nambucca Heads to Newcastle.

The bioregion is influenced by a warm temperate climate, which shapes the distribution of marine species. While it lacks the subtropical influences of the Tweed-Moreton region, the Manning Shelf still supports diverse marine life, blending temperate species with occasional tropical migrants.

Its estuaries are among the most significant habitats, with seagrass meadows and mangroves serving as important nurseries for fish, crabs, and prawns. Rocky reefs support vibrant communities of algae, invertebrates, and fish and coastal wetlands and mangrove forests provide critical ecosystem services, including carbon sequestration, water filtration, and coastal protection.

Marine protected areas play a crucial role in conserving the unique habitats and species of the Manning Shelf marine bioregion. Notable sites include the Port Stephens-Great Lakes Marine Park where marine sanctuaries have been established to maintain ecological integrity and protect threatened species.

Marine sanctuaries have been established at: 

• Port Stephens - Great Lakes Marine Park | 98,000ha | 18% sanctuary