One of Australia's oldest historical sites is being transported back in time 400 years to recreate an ecosystem as it existed pre-European settlement.

Dirk Hartog Island off Western Australia's northern coast is the site of one of the world's largest ecological restoration projects, which aims to return the isle to what it was before Dutch explorers first landed there in 1616.

The 20-year project has just this month enabled the island to be declared free of feral cats, goats and sheep — paving the way for the reintroduction of native animals in the hope of providing threatened species with what Dirk Hartog Island Ecological Restoration Project manager John Asher called a "sanctuary to thrive".

"This is a very exciting project, there's nowhere else in the world you can return a whole suite of animals to back to when white man first arrived on our shores," he said.

"When Dirk Hartog arrived on Dirk Hartog Island back in 1616, there was 13 species of ground-dwelling animals on the island, and since 150 years of pastoralism and feral introduction of cats on the island there's only three left.

"We can get all of these 10 animals back on the island and, if we can recover them, we can then use them as stock to spread elsewhere in Australia as well."

A national park 400 years in the making

Hartog became the first European to discover the island. He was on his way to Java onboard the Dutch East India Company ship Eendracht when he stumbled across it by accident.

Before leaving he nailed a plate, inscribed with his name and the names of other senior crew members, to a post on the island

The plate is the oldest surviving European artefact relating to Australia and was later collected by another Dutch explorer and taken to The Netherlands.

Hundreds of loggerhead turtle tracks along Turtle Bay on Dirk Hartog Island. ( ABC Midwest and Wheatbelt: Chris Lewis )

It was not until almost 100 years later, in 1772, that French explorers would also stumble across the island, and in 1869 Francis Louis von Bibra was granted a lease there and established a flock of sheep.

It remained a pastoral lease for 150 years until 2009 when it was declared a national park with the aim of returning the island to a time pre-dating white settlement.

"The long-term goal for this project is to recreate the ecosystem that was once there on the island prior to the land practices that we introduced once it was settled," said Department of Biodiversity Conservation and Attractions director of science and conservation Margaret Byrne.

Loggerhead turtle hatchlings on the island make their way to the ocean. ( Supplied: Department of Biodiversity, Conservation and Attractions )

The first step of the restoration project was undertaking the huge logistical task of removing thousands of feral cats, sheep and goats from the island, which is 80 kilometres long and 15km across at its widest point.

The cat eradication involved three years of careful planning before four years of intense baiting across the island.

"It has been a difficult task. The island is 63,000 hectares so it's the largest island in the world feral cats have been removed from," Ms Byrne said.

"The key thing we needed to do was remove feral cats. Feral cats are a major predator of small mammals.

Dogs were used to help detect cats on the island. ( Supplied: Department of Biodiversity, Conservation and Attractions. )

"We actually put a fence across to create two cells, so we had a northern part of the island and a southern part of the island. The island was then baited and that enabled the monitoring in the southern area first and then the northern area.

"That came from our science experts being able to understand what the complexities of the field operations would be and bringing that expertise to bear and understand what was the right way to design the program so we were going to achieve outcomes with the minimum amount of resources."

Baits were used to eradicate feral animals on the island. ( Supplied: Department of Biodiversity, Conservation and Attractions )

Hare-wallabies the first to be relocated

Native animals are now being reintroduced with 140 rufous and banded hare-wallabies from nearby Bernier and Dorre Islands becoming the first to be relocated to the island.

The remaining species will be reintroduced in the coming years.

Banded hare-wallabies are among the first animals to be relocated to the island. ( Supplied: Department of Biodiversity, Conservation and Attractions )

A pair of released hare-wallabies. ( Supplied: Richard Manning, Department of Biodiversity, Conservation and Attractions )

"By creating new populations, additional populations of species then we reduce the probability of extinction," Mrs Byrne said.

"The more populations we can have in islands, where we can remove threats … then we are improving probability of persistence of those species."

WA Environment Minister Stephen Dawson said the project was part of a broader suite of measures the State Government was undertaking to create animal sanctuaries for threatened species around the state.

"Over the past 200 years, we've seen our species threatened because of land clearing, because of urbanisation, so to have arks like this available in the state where we can restore the animals is very important," Mr Dawson said.

"So this project is really important for the bandicoots, the chuditch, the dibblers and all sorts of other animals that have been under threat since white colonisation of Australia."