Measures to protect the critically endangered grey nurse shark have been announced by the NSW government.

Minister for Primary Industries Katrina Hodgkinson introduced regulations that include banning baited hook fishing in key breeding areas for the species along the NSW coastline.

"Our overall goal is to protect the grey nurse shark," she told reporters at Manly Sea Life Sanctuary today.

"They are the puppies of the ocean - they're not Jaws.

"They are very gentle creatures but we're down to the last 1500 or so."

Bait fishing presents the biggest risk for grey nurse sharks, the minister said.

Recreational fishers will still be able to use other methods such as spinning, jigging and hand gathering.

The moves "strike a balanced approach" to protect the sharks while allowing fishing and scuba diving to take place, Ms Hodgkinson said.

"Because the population is so low, before protection they're on a pathway to extinction," said Dr Geoff Allan, executive director of Fisheries NSW.

Critical habitat scuba diving regulations are being replaced by a code of conduct as part of the protection moves, developed over the past 14 months.

Other changes include delisting the Bass Point critical habitat site in Shellharbour and protecting a site near Mermaid Reef, off Crowdy Head.

An educational campaign will promote the rules and there will be a 12-month compliance advisory period while they are phased in.

Responding to the new measures today, Greens MP Cate Faehrmann said protection zones around aggregation sites needed to be larger.

"When you are desperately trying to save a critically endangered species from extinction, half-hearted compromises are not the way to go," she said.

AAP