Trouble in paradise: Lord Howe Island divided over plan to exterminate rats

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Rodents are threatening the unique natural environment of Australias sparsely populated Lord Howe Island. But a plan to eradicate the pests by dropping 42 tonnes of poisoned cereal is dividing the close-knit community in half

Described by the UN as a zone of spectacular and scenic landscapes, Lord Howe Island is nothing if not dramatic. Formed from an inferno of underwater volcanoes more than six million years ago, the 10 km long crescent-shaped island sits in a bath of turquoise water, exactly where the warm East Australian Current meets the icy waters of the Antarctic Circumpolar Current.

Those ancient lava flows left a rugged landscape with steep cliffs, which drop off into an ocean which supports the worlds most southerly coral reef. Between those cliffs and the reef lies a calm blue lagoon that laps against a yellow-sand beach.

But now theres difficulty in paradise.

Listed as a world heritage site, Lord Howe Island is home to hundreds of species of plants and animals found nowhere else in the world, along with 350 people who, isolated from Australias mainland by 600 km, form a close-knit community.

That little community is being torn apart. By rodents. Or rather, what to do about the rodents that are threatening that unique environment.

A plan drafted in 2009 to fell 42 tonnes of poisoned cereal on the island to eradicate it of mice and rats has divided the community in half.

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Black rats are thought to have caused the extinction of five species of bird and 13 invertebrates on Lord Howe Island. Photo: Jelger Herder/ Buiten-beeld/ Minden Pictures/ Corbis

Years of bitter conflict about whether to progress with the eradication led to a poll in May last year referred to on the island as the referendum in which 48% of respondents voted against pursuing government approval for the eradication. And the disagreement is fierce.

The journey to this split involves shipwrecks, the worlds largest stick insect, the psychology of small islands and a touch of conspiracy. The scenario, still playing out on the island, is shown how preservation can be as much a social science as an ecological science.

Until about 1860, Lord Howe Island was free of mice and rats. Then, somehow or other, mice were introduced. They began to eat native bugs and plants and compete for food with native birds. But their impact on the native plants and animals is not completely clear.

Then on 15 June, 1918, the SS Makambo, a steamship carrying fruit and vegetables, ran aground. It was repaired and refloated within 10 days, but not before black rats scurried off the ship and set up home on their new island paradise.

That was the beginning of the end for several unique animals. Over the coming years, the rats are thought to have caused the extinction of five species of bird and 13 invertebrates that arent discovered anywhere else in the world.

Today rats continue to threaten 13 more birds and two species of reptiles.

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The Lord Howe Island phasmid, or stick insect, is on the list of critically endangered species. It was thought to be extinct by 1920, and in 2001, 24 insects were rediscovered by on Balls Pyramid. Photo: Tracey Nearmy/ EPA/ Corbis

But somewhat strangely, one uncharismatic animal has grabbed the spotlight and focused international attention on the 14.55 sq km Australian island and its big rat problem.

The Lord Howe Island stick insect also known as the Lord Howe Island phasmid or tree lobster was presumed extinct. The largest stick insect in the world, it was a regular dinner for hungry rats, and within two years of the invasion, sightings of the once common insect had ceased.

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Cargo steamship SS Makambo, which operated aground off Lord Howe Island in 1918, introducing the black rats which now plague the local wildlife. Photograph: Samuel J Hood/ Australian National Maritime Museum

But in 2001, based on a hunch, a squad of scientists scaled a premonition rocky outcrop 23 km south-west of the island called Balls Pyramid, where it was unlikely rats had colonised. After scaling the mount and not seeing any of the phasmids, the scientists resigned themselves to heading home empty-handed.

On their descent they discovered droppings that seemed too large to be from any other bug and decided to return at night when the phasmids were known to be active. When they came back, they found a small colony of 24 living there.

After 81 years of extinction, the phasmids were back.

Two years later, after a revival scheme had been established, the team returned and took a breed pair, named Adam and Eve, to Melbourne zoo.

Now were in our 12 th generation from the original pair says Rohan Cleave from Melbourne zoo, who manages the breeding program. Last week we hatched our 13,000 th baby nymph thats the number that hatched since 2003, when we hatched our first ones.

The early couple of weeks were really stressful. Not knowing anything about the species except one particular bush they might have feed, Cleave says. But were here hatching them almost every day in 2016.

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Balls Pyramid, the bumpy outcrop 23 km south-west of Lord Howe Island, where the stick insect was rediscovered by scientists in 2001. Photo: Kevin Schafer/ Corbis

Now, bred back from the verge of extinction, the phasmids are being flown around the world. Last year the latter are flown to a zoo in Bristol and one in Toronto. And this year a group were flown to San Diego for breeding. Besides being a unique exhibit for those zoos, they act as insurance in case something happens to the collecting at Melbourne zoo, explains Cleave.

Although theyre jet-setting around the world, they cant go home to Lord Howe Island yet, says Cleave. Thats always been the hope from the start of the program, he says.

There are some in enclosures on the island where the stick insects are breeding, but until the rats are gone, this strange, ancient animal cannot live free.

Not everyone is a fan of the phasmid.

It infests houses and feeds crops. Its a nuisance. Its ugly. Ugly and frightening, says Rob Rathgeber, a resident on the island who has been a vocal opponent of the rat eradication. Rathgeber is retired now but has a science degree and was a businessman.

Rathgeber doesnt want the phasmid back. Despite what the scientists say, hes not persuaded the rats killed it in the first place. And hes deep worried about the health impacts of a rat eradication program that spreads poison across the island. Hes concerned by the proposed utilize of aerial baiting where poisoned pellets are thrown from helicopters.

This stuff is going to rain down on the island. Its going to come on to our rooftops. Its going to be in the soils, he says.

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Lord Howe Island stick insects are prepared for a flight to San Diego where they will be housed and bred in a zoo. Photo: Melbourne Zoo

Despite assurances to the contrary, Rathgeber thinks its likely people will be poisoned by the baits, that it could cause birth defects, that how to deal with poisoning isnt so clear and that it will kill many of the islands animals.

We will be the first permanently populated island that will have this therapy. The very first. Well be the guinea pigs, he says.

Rathgeber is so convinced of the peril and nonsense of the scheme, he argues there must be a fiscal motivating behind it. I think its at a higher level of government.

All these asserts are wrong, according to island authorities and others who have studied the science.

Penny Holloway is the CEO of the Lord Howe Island Board the islands equivalent of a local government. She says residents fears are largely misplaced. The risks to humen are negligible, she says, and the bait wont be fallen anywhere near houses. Most of the island is uninhabited, and using helicopters is the only feasible way of baiting the remote regions, she says.

According to Ian Hutton, a naturalist, photographer and tour operator from Lord Howe Island, the no voters seem to be motivated by a mix of suspicion of mainlanders, a distrust of government and a legitimate concern about the possible unintended the effects of the intense employ of poisons required to wipe out vermin in one fell swoop.

Some people in a small community resent authority, says Hutton. People living on the island have lived here for six generations and feel ownership of the island and maybe the scientists that initially came here werent skilled with communicating to small communities.

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Most of Lord Howe Island is uninhabited, with a population of just 350 people. Photograph: R Ian Lloyd/ Masterfile/ Corbis

But should the islanders be happy about 42 tonnes of poisoned cereal being dropped on the island from the sky?

It certainly sounds like a lot. But Hutton says actually, its a style of lowering the amount of poison used in the medium and long term. The control program that currently maintains rat numbers down is putting poison into the environment continually.

In that 42 tonnes of bait under the proposed eradication program, there will actually be less than 1kg 840 g of brodifacoum, a poison in common pesticides like Talon which is found in most supermarkets. According to the World Health Organisations International Programme on Chemical Safety, the fatal dosage for an adult is about 15mg of brodifacoum. That means a lethal dosage would be achieved by eating about 2.5 litres of the poisoned cereal.

Holloway says if the eradication runs, it will end the need for constant baiting. Poison is laid out in organised blitzes every 10 weeks and is distributed to residents to help with infestations on their properties. Almost two tonnes of bait is used each year in the control program, Holloway says.

Whats more, although residents are asked not to use commercially available Talon to avoid breeding rats that are resistant to it, it is for sale in stores on the island and residents have been known to bring it over from the mainland too.

Controlling rats means you have to use poison baits eternally, she says. With an eradication you have to make sure every single rodent on the island has access to a bait at a single point of period. That frets people. But once youve done that you dont need to use baits any more.

Far from raining down on roof, Holloway says no aerial baiting will occur within 150 m of an occupied build without permission from the owner, and it would never occur within 30 m of a building. In inhabited regions, bait will be placed in covered bait stations.

Rat eradication programs, including ones with aerial baiting, have occurred on several other islands in countries including New Zealand, the US and Seychelles, so she doesnt guess Lord Howe is being treated like a guinea pig.

But the fact so many islanders have been persuaded by arguments against an eradication program indicates the scientists and governing board have a lot of work to do. Holloway says the board is now consulting intensely with the community, surveying every landholder to try to understand their concerns and more clearly explain the facts of the eradication program.

Meanwhile, scientists are continuing to investigate the very real risks of such an intense baiting program. Theyve saw the poison could kill some birds, and part of the plan is to catch almost the entire population of those species and keep them in enclosures for a few months.

And this month, trials are going ahead to make sure mice, which require a higher dose of the poison to be killed, wont perversely benefit from their ratty neighbours dying in higher numbers.

The 52% vote in favour of trying planning and acceptances entails the program could begin as early as January 2017, pending approval under the federal Environmental Protection and Biodiversity Conservation Act, and from the Australian Veterinary and Pesticides Medicines Authority.

Meanwhile, Cleave says the jet-setting stick insects have arrived in San Diego and are enjoying their new home.

Looking towards the future, Hutton says most people are open-minded and since the referendum, many have shifted towards supporting the eradication.

Holloway says pending the various government approvals and further consultation, it is hoped the eradication will proceed in early 2017.

But divisions among the human dwellers might be harder to eradicate. In May last year, the federal commissioner for threatened species, Gregory Andrews, travelled to Lord Howe and spoke with a group of islanders. I feel sad for the Lord Howe Island community that the decision on how best to address a pest species problem is make such division, he was reported as saying in the Lord Howe Island Signal, the local newspaper.

Speaking now with Guardian Australia, Andrews is more upbeat. The islanders eradicated feral cats about 30 years ago and theyve get rid of the donkeys and the goats. Theyre doing an exemplary task protecting a world heritage area, he says.

Andrews believes saving threatened species requires as much knowledge about humans as it does about the animals they are trying to save or eradicate.

At a higher level, I believe the ecological science was done, but not the social science. And what it taught me was that the journey of saving our wildlife is one we need to go on together. You cant barge through.

Read more: www.theguardian.com

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