Environmental Engineering Reference
In-Depth Information
You can't get anywhere much more remote than the British-administered island of South Georgia in
the Southern Ocean near Antarctica. In January 2013, the island had unusual visitors. A team of reindeer
herders from the Sami people of Lapland in northern Norway made a long trip south to corral and shoot
the world's most southerly herd of reindeer (
Rangifer tarandus
). It was going to be a big job, over two
austral summers. The island was overrun with almost seven thousand reindeer, all descendants of anim-
als introduced to the chilly pastures a century ago as a handy local food source for passing Norwegian
whalers. But whaling ceased in the 1960s. Since then, apart from during the island's brief capture by
Argentine troops in 1982, South Georgia's only inhabitants have been visiting scientists and officials.
Nobody had been eating the reindeer, and their numbers soared.
The reindeer were accused of trampling native plants, including the tussock grasses where burrow-
ing seabirds nest. Conservationists fear that, as the island's glaciers melt, the numbers could grow fur-
ther, dooming the birdlife. The island is home to colonies of indigenous pintail ducks, burrowing petrels,
and South Georgia pipits, the world's most southerly songbird. So the Sami visitors herded the reindeer
into pens, where each was finished off with a gunshot to the head. In areas where the terrain made that
impossible, the animals were tracked down by Sami hunters. By the end of the 2014 hunting season,
the last of the reindeer had been killed. Some of the carcasses across the island were left lying, while
others were cut up and sold to cruise ships, though many reindeer joints remained in cold storage in the
Falklands.
9
But the reindeer are not the only target of the ecological restorers. To protect the bird colonies, they
also reckon they have to eliminate the island's millions of brown rats (
Rattus norvegicus
), whose ancest-
ors first scuttled ashore from the boats of eighteenth-century seal-clubbers. Like the reindeer they found
no natural predators but plenty of birds' eggs to eat. So, even as the reindeer were rounded up, three
helicopters began crisscrossing the island, their pilots braving gale-force winds and blizzards to drop
onto the tundra the first load of one hundred million pellets containing the anticoagulant brodifacoum.
The four-year rat eradication is costing $10 million, paid for by Frederik Paulsen Jr., a Swedish phar-
maceuticals billionaire, keen ornithologist, polar explorer, and founder of the South Georgia Heritage
Trust. If successful, the South Georgia purges will be one of the largest deliberate eradications of an
alien population of animals ever. The aim, says project leader Tony Martin from Scotland's University
of Dundee, is not just to maintain a fragile status quo but to get back “to the way things were before
1775,” the year Captain James Cook claimed the island for Britain. It will allow millions of birds to
return. For the program to be a success, “every single rat must be eradicated.” But that requires bom-
barding the island with some 270 metric tons of a persistent poison, with a half-life in soils of around six
months. Some think that is a price not worth paying. The consequences are too uncertain. Ken Collins
of Southampton University, a British specialist on island ecology, told me: “They are flooding the island
with poison. I am a bit open-jawed about that.”
An obvious concern is that birds might be poisoned too. The scientists involved admit this is a risk,
particularly to the brown skua, which partly feeds on rat carcasses, but also to endemic South Georgia
pintails and sheathbills. Critics point out that when the same poison was tried on Rat Island in the Aleu-
tians, the most conspicuous victims were forty-one bald eagles that died after eating dead rats. “Some
non-target (bird) mortality is sadly inescapable, but losses will be recovered over the space of a small
number of years,” the South Georgia Heritage Trust told me, at the halfway stage of the operation.
10
Even if Paulsen's pogrom gets rid of the rats, there will still be the mice. Once thought rare on South
Georgia, it now seems that they have all along been hunkering down in their burrows—albeit in small
numbers where there have been rats.
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The rat bait will kill mice, but they are much harder to reach
because they only feed in small areas and may miss the poison. As the rodent eradication plan drawn
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