Twenty-five high-value biodiversity marine sites around the Sydney region will get enhanced protection as part of a long-awaited marine park proposed by the Berejiklian government.

The sites, stretching from Newcastle to Wollongong and taking in parts of Sydney Harbour, include sanctuary zones allowing activities such as boating and diving, and conservation zones where extraction will be limited to such species as abalone and lobster fishing.

Marine park view: Premier Gladys Berejiklian (centre), with Gabrielle Upton, Environment Minister, and Bruce Notley-Smith, member for Coogee, at Thursday's announcement. Credit:AAP

“NSW’s beautiful marine environment is iconic and the envy of the world," Premier Gladys Berejiklian said on Thursday. "We want to keep it that way so that future generations can continue to enjoy it.”

Environmental groups generally welcomed the plan, which is open to public consultation for six weeks. That's despite the sanctuary and conservation zones only covering 2.4 per cent and 2.2 per cent, respectively, of the bioregion known as the Hawkesbury Shelf. Together, the zones amount to about 9100 hectares.