Covid restrictions, enforced at the start of the school holidays, have decimated the bottom line for many of the region's popular tourism attractions.

Owner of Port Jet Cruise Adventures Jodi Heeney said they have seen a dramatic drop in numbers since the tough restrictions were introduced on June 26.

"The holiday period is usually our busiest time and it's also peak whale watching season at the moment, but we've now lost around 90 per cent of our bookings," Jodi said.

Port Jet Cruise Adventures made the difficult decision to deny entry to passengers from the Greater Sydney lockdown area, which Jodi said is where the majority of their usual visitors come from.

"We've just been doing refund after refund. It's just very unfortunate timing for us," she said.

During a normal school holiday period Port Jet Cruise Adventures will take out as many boat loads of people whale watching as they can, however they are now down to two small boat trips a day and aren't conducting the river cruise trip.

"It's about a quarter of what we would usually be taking out and the restrictions will be in place for the whole school holiday period," Jodi said.

"The holidays are just gone for us."

Visitor numbers have also dropped for Billabong Zoo, with the school holiday period usually being their busiest time.

"We've had two years of having a tough time and we rely on school holidays to play catch up," owner Mark Stone said.

"We do appreciate the people who are coming out to visit the zoo and we're hoping locals will support us through this time."

Mark said they have noticed a number of locals using their Dine & Discover vouchers when visiting the zoo which is helping encourage people to support local businesses.

"We've been watching what other zoos have been doing and following the trends to keep people wanting to come back. Our industry is different because there's usually a time period before people come back and visit a zoo, it's not something you do all the time," he said.

"The Dine & Discover vouchers have been great in encouraging locals to support local businesses like ours."

Mark said it's difficult for zoos to cut costs when visitor numbers are down.

"The cost of feeding animals continues even when we don't have many people walking through the doors and that's why we do appreciate those who are coming out here," he said.

"It's a big push for us to continue when we get such positive responses from the community about the work we do."

The Port Macquarie Koala Hospital has also closed its doors to visitors until July 10 due to the current restrictions.

"It is a difficult decision to close the Koala Hospital, however our priority is always the wellbeing of our staff, volunteers and our visitors," a post on the Koala Hospital's Facebook page stated.

"We will look forward to welcoming you to the Port Macquarie Koala Hospital when this outbreak is under control."

In ALL other parts of NSW the following restrictions will apply until July 9:

People across NSW should only enter Greater Sydney for essential purposes.