Some locals say Great Barrier Island, a small island of 800 people and a "fragile" economy and environment, is bearing the weight of a Government eager to exploit its $4.3 billion potential in gold and silver.

Others are desperate to get what's best for the island.

Of the five regions announced yesterday to have conservation land opened up for mining, it is the one that has been heaped with most political attention.

Auckland mayor John Banks, Manukau mayor Len Brown and even a National MP, Auckland Central's Nikki Kaye, have spoken out against the plans.

The Government stocktake of the country's mineral riches, meanwhile, cites a site with "excellent potential for gold-silver occurrences" worth $4.3 billion.

The site is Te Ahumata Plateau, or, as locals call it, White Cliffs, named after magnificent white bluffs on its northeast face. Locals say an international mining operation would change everything - not just with the plateau, but on the whole island.

"We need all the help we can get so we don't lose the intrinsic value of the beauty of this land. If they do anything like putting great scars on the side of it...," said Alan Gray, born on Great Barrier Island, 1933.

"It's absolutely beautiful. We can show it with pride to people who come to this place.

"We just don't want it spoilt."

White Cliffs was mined in the past, before World War I, with giant battery rams crushing rocks with such clamour that, the story goes, it could be heard in the Coromandel, across more than 20km of ocean.

Cores of silver six inches (15cm) in diameter and a metre long are said to have been pulled out of the ground.

Mr Gray said in his youth the cliffs had been riddled with holes, later covered up by a regrowth of vegetation.

"It was like a whole lot of gophers had been all over the place," he said.

He does not want to see it repeated, even as the Government has marked to remove protections from 705 hectares - about the area of a circle 3km across.

"It's a complex set of circumstances and we don't need to be treated with disrespect by the Government or anyone else deciding they're going to rape this place," Mr Gray said.

In the last census, in 2006, 852 people in 453 houses were counted on Great Barrier Island.

It was a loss of one in six people in just five years.

Tony Litherland, who lives in Whangaparapara, from where he can look out to White Cliffs, has been on the island for 30 years, watching its population steadily shrink.

"Mining would certainly give a bit of employment to the young people, because at the moment there's nothing," Mr Litherland said.

"There's no industry on the island so anything that brings an economic benefit to the island is a good thing."

He ran a fishery depot for 25 years until he retired, around the same time as fish prices plummeted internationally and the local industry collapsed.

Some of the former fishermen are now working on ferries or at contractors. The others have retired or moved away.

There are still young people on the island, but "how they make a living, I don't know", Mr Litherland said.

Tourism booms during the summer but shuts down the rest of the year, and "you can't eat trees", he said.

Great Barrier Island needs the economic benefit regardless of potential disruptions, he said.

"You might be able to see whatever operations they do from here, but no one will be able to see it from where they live ... A lot of people have never even been up there.

"If it's done in a sympathetic way it will be good for the island," Mr Litherland said.

But Judy Gilbert has serious doubts. There is a small quarry on the island, already causing enough pollution in waterways and contention in the community.

"We've got a local quarry that's a huge eyesore. Look at our quarry and magnify it by 100 times. It's been really hard to hold the contaminants off that," said Ms Gilbert, who has owned land on the island for 33 years.

"Mining is a huge industry in terms of size and vehicles and all of that. That's going to change the whole atmosphere of the place. From an environmental point of view it would be tragic."

White Cliffs was unusually exposed and dry, creating a unique environment crucial for biodiversity, she said.

"It's quite an iconic bit of landscape. Quite a lot of people take water from it. There's a very rare lizard up there. There's a lovely walk up there; it's one of the popular walks."

Great Barrier Island was "subsidised" by the Auckland District Council, she said. It gets $4 in maintenance - including for its roads and airport - for every dollar it pays in rates.

Half its inhabitants earn less than $30,000, and half are older than 50.

"We have a very fragile economy, there's no doubt about it. But that benefit is never going to outweigh what they're going to do to our environment.

"On the island the environment is our bank - that's all we've got to bank on to encourage people to visit and live here."