ANNE KRUGER, PRESENTER: Hello, I'm Anne Kruger, welcome to Landline.

By now the mercury's dropped sharply in many parts of southern Australia. Indeed, it's been cold enough for snow in the Alps. But spare a thought for those who live and work in the deep south on rugged Macquarie Island in the sub Antarctic.

Last month a team of specialists from Australia, including a dozen sniffer dogs, landed on the world heritage-listed island to start a 5 year, $25 million pest eradication program.

They will be targeting rats and rabbits to give native vegetation and the penguin seals and sea birds who breed there a break.

ABC reporter Tracy Bowden prepared this special report for Landline.

ONSCREEN: Out of bounds

(Waves crash against rugged rocky outcrops)

TRACY BOWDEN, REPORTER: Macquarie Island is one of the most remote land masses on earth, a windswept spot in the middle of the Southern Ocean about halfway between Tasmania and Antarctica.

The island is 34 kilometres long and five kilometres wide.

Its rugged beauty and diverse wildlife touch all those who make the long journey here.

JAMIE DOUBE, EXPEDITION MEDICAL OFFICER: It's a pretty amazing place to live from a biological point of view. It's almost like living in some sort of nature documentary. There are so many animals packed in such a small space.

(King penguins huddle together on the rocks)

Many of the seals, the albatrosses and similar birds - and many species of penguin that may feed further south - want to lay their eggs on the last bit of sort of normal, green-covered dirt rather than ice, and that's what Macquarie Island represents.

ROB CLIFTON, VOYAGE LEADER: It is this amazing place with a dynamic weather system and wildlife absolutely everywhere. And it's very raw, the place is incredibly raw.

TRACY BOWDEN: This really is a remarkable spot. The penguins- these are king penguins, one of the species on the island, and they just wander right up to you, clearly not at all afraid.

Elephant seals are flopping all over the beach but their environment is under threat.

(Long shots of Macquarie Island landscape)

ROB CLIFTON: The damage that has been done to the natural environment here is just staggering - literally brings tears to people's eyes who know the place and know what the landscape looks like.

TRACY BOWDEN: A massive operation coordinated by the Tasmanian Parks and Wildlife Service and funded by the Tasmanian and Federal Governments hopes to address the problem once and for all. The goal is to eradicate three non-native species from the island: ships rats, house mice and rabbits.

Keith Springer is the project manager.

KEITH SPRINGER, ERADICATION PROJECT MANAGER: The only way to allow the vegetation and native wildlife to recover is to remove the impacts of those invasive species.

TRACY BOWDEN: The sealers who came to Macquarie Island in the early 1800s have a lot to answer for.

First they hunted fur seals to the point of extinction, then they began hunting elephant seals. Next, penguins.

(Large cylindrical devices rust in the grass)

Believe it or not these are penguin digesters.

Back in the 1800s hunters would corral any penguins that were in this area, shove them into the top of the device, boil them up overnight and then the oil was drawn off into barrels which became heating oil.

JAMIE DOUBE: Up to 2,000 penguins were stacked into one digester at a time. Now it does seem barbaric and pretty horrific to us but I suppose we have to remember that this was before we had much mineral oil.

So if we wanted to have oil to run our lamps or oil to rub into our jackets to make them waterproof or to protect our ropes or to lubricate our cart bearings we needed oil, and at that stage we were using oil from animals.

TRACY BOWDEN: Then in the 1870s the sealers introduced the European rabbit to the island as an alternative food source.

KEITH SPRINGER: Their diet was very limited, sort of salt pork and bully beef and ships biscuits and that sort of thing, and what they could get from penguins and seals. So rabbits were a very welcome form of alternative food for them.

So I guess they just didn't have the foresight or maybe the values to think of what those rabbits might do to the island once the sealers had left.

TRACY BOWDEN: But by the 1970s there were more than 100,000 rabbits on the island.

They wreaked havoc with the vegetation, causing soil erosion and destroying nesting burrows. Myxomatosis reduced the population for a time but the rabbits developed immunity and their numbers again grew.

STEVE AUSTIN, DOG TRAINER: I think it's ... first to say I think we're making history. I think this is the first dog training ever in the middle of the Great Southern Ocean.

TRACY BOWDEN: As they head south for Macquarie Island on board the ice-breaker the Aurora Australis, 12 key members of the eradication team are being put through their paces by trainer Steve Austin.

STEVE AUSTIN: First thing we're going to do is get some dogs on some steadiness. This has taken a lot of dogs to get here.

I mean, what you see now is the end result of probably 40 or 50 or 60 dogs that have gone through processes that haven't made it. These dogs are the cream of the crop.

These are the SAS of dog or rabbit dogs, you know.

(To handlers) Stay your dogs!

Good. Praise them, good dogs.

They won't be killing anything on the island. Their job is to detect where the rabbit is sleeping or laying up, where the urine and where the dropping is.

TRACY BOWDEN: The dogs' work will come later. First a team of four helicopters distributes hundreds of bait pods across the island ready for aerial baiting.

The bait is in cereal-based pellets and contains the toxin brodifacoum, an anti coagulant often used in domestic rat poison. Three hundred tonnes of bait will be used.

Macca, as the locals call it, has never been busier. Normally there would be about a dozen people working here at the Australian Antarctic Division research base but the eradication program means that this year there's more than three times that number.

(lush, tall grass within fenced area, surrounded by close cropped expanses)

This is a really clear example of the damage done by the rabbits. This small area has been fenced off and shows the sort of vegetation you'd normally expect to be all over these hillsides, including the Macquarie Island cabbage.

But if you look up the hill, a mass of rabbit warrens. This is the damage they've done.

Thanks to relatively fine weather, the program is off to a good start. Ninety per cent of the island has now undergone the first bait drop.

IVOR HARRIS, OUTGOING STATION MANAGER: This year we've proceeded the aerial baiting program with distribution of the rabbit calicivirus, which has already had a very significant impact. So we know we've already reduced the rabbit numbers very considerably.

TRACY BOWDEN: The aerial baiting is being staged at this time of year because there are fewer native animals on the island which could be harmed, but project manager Keith Springer said there will be collateral damage.

KEITH SPRINGER: The death of some birds in this case can be expected, so it's a reality that we needed to accept early on. We have long term goals for the project and so, you know, in 50 years time, for example, and onwards, with the benefits to those species have accrued to the point that the mortality in the first instance is outweighed.

TRACY BOWDEN: The program is not without its critics. Last year baiting was stopped due to bad weather but not before hundreds of native birds were killed.

It's also been suggested that the eradication of cats on the island a decade ago was a mistake which only made the rabbit problem worse.

There was a suggestion that mismanagement was a part of this because the cats were eradicated and then you had an extra problem with the rabbits.

KEITH SPRINGER: I think it was a factor but it would be an oversimplification of the situation to suggest that that was the reason, and it may not even have been a strong reason.

TRACY BOWDEN: The specially trained dogs from Australia and New Zealand are settling into the place which could be home for several years.

This is quite a scene, seeing dogs just a few metres away from penguins and not flinching, what's this exercise all about?

STEVE AUSTIN: This exercise, Trace, is to make sure when the dogs are working around native wildlife at Macquarie that they don't go anywhere near them and don't have any attempt to hurt them. So it's very important, and probably the most difficult part of the training the dogs have to go through.

TRACY BOWDEN: So what would a dog's instinct be when it saw a penguin normally?

STEVE AUSTIN: We'll leave the niceties out of it, I suppose - probably grab one, maybe. Being a labrador, a springer - pheasants and partridges. It's all in their nature to go out and bring the bird back to the table, you know?

So it was very difficult for Gus and I to train the dogs to ignore those- all sorts of birds.

(To Gus) I reckon all that rabbit sign is going along that bottom basin, they've been coming down towards that sand.

TRACY BOWDEN: It's anticipated that the aerial baiting won't be enough and that's where the dogs come in.

Their job is to track down any remaining rabbits.

(Yellow lab tracks across a hillside)

GARY BOWCOCK, DOG HANDLER: There is a rabbit down in that hole. She's telling me that there's something in there, it's a rabbit and that's what she's been trained on. She's scratching it out, wanting to get down to it.

TRACY BOWDEN: Dog handler and veteran rabbit hunter Gary Bowcock will spend the next 12 months on the island.

GARY BOWCOCK: We'll put some gas down the hole and then we'll block the hole and then that will gas the hole.

And we'll also GPS the area and then we go back and tell the hunters hey, there's some rabbits around this area and come back and deal with them.

And then they will use a variety of methods to do it, either shooting, night shooting, shooting in the daytime, putting out traps or putting out poison.

STEVE AUSTIN: It's not only finding the very few remaining rabbits but it's also motivating the dogs and the handlers to continue for a few more years to make sure there's nothing there and the motivation of the dogs and the handlers. Because you know, success is not finding a rabbit, that's success.

But as far as the dogs are concerned that's not success. So it's going to be some interesting times ahead.

GARY BOWCOCK: The calicivirus has taken a lot out so it's sort of a competition unofficially between everyone who's going to get the first rabbit and who's going to get the last one. So it's really exciting on that. Everyone's keen and roaring to go.

TRACY BOWDEN: This is a long-term project. Only after there have been no rabbit sightings on the island for two years can the team declare victory.

Now, control isn't enough. You need to remove every last rabbit, don't you?

KEITH SPRINGER: Any individual that remains means that we've failed in the entire project. So there's no half measures with success, and a single breeding pair left on the island of mice, rats or rabbits would mean that we've failed in that goal.

JAMIE DOUB: If something occurs here, if we do succeed at getting rid of the rabbits, it will make a difference to this place forever.

The vegetation behind us will come back to what should be the cabbage amongst the tussock. A lot of the animals that live burrowed in there- there's birds that now cannot live in there because they're eaten by the rats.

As soon as the rats go they will come back. We know that they will come back because they keep trying to come back. They've been trying to come back every year that I've been here but they can't succeed.

(Boat fog horn blares)

TRACY BOWDEN: As outgoing station leader Ivor Harris heads home, he ponders the future of the long awaiting program and of Macquarie Island.

More than $25 million, lots of people, lots of time, an enormous amount of effort. Some might say, is it worth it?

IVOR HARRIS: How do you place a dollar value on something that is as biologically unique and special as Macquarie Island? It's just an amazing place. It's the only one in the world like it, and if we can't look after Macquarie Island it will be a sad day.