OSLO: About 3,000 reindeer on an island near Antarctica are to be slaughtered to stop damage to the environment by the descendants of a tiny herd introduced a century ago for food by Norwegian whale hunters.

A 16-strong team, mostly Sami reindeer herders, has arrived in South Georgia, a British overseas territory, and is preparing to round up and cull all the reindeer on an island that is home to penguins and seals and has no native grazing animals.

"The reindeer have become very destructive," Reidar Andersen, director of the Norwegian Nature Inspectorate which oversees the team, told Reuters. Reindeer naturally live only in the Arctic or sub-Arctic regions at the other end of the globe.

The animals have trampled native plants, such as tussac grass, caused erosion and pose a threat to South Georgia's king penguins and local birds such as the pipit and pintail by destroying their nests.

The team was working this week to set up fences and a corral for the reindeer, based on Sami traditions, Andersen said.

Most reindeer will be slaughtered with a bolt gun shot to the head. Some in remote areas, or those near penguins where stampeding reindeer could trample birds, will be shot by rifles. The project is likely to last for two southern hemisphere summers.

The reindeer are part of a global problem of invasive species - animals or plants that take over new habitats, like European rabbits in Australia or Asian carp in U.S. rivers. Invasive pests can spread disease and undermine food production.

One estimate a decade ago of the global damage caused by invasive species was $1.4 trillion a year, said Geoffrey Howard, global invasive species coordinator for the International Union for Conservation of Nature (IUCN).

"It's almost impossible to know the cost," he told Reuters by phone from Nairobi. "How do you work out how much a badger is worth, or the value of an elephant?" The IUCN groups governments, scientists and environmental organisations.

In South Georgia, reindeer were introduced in the early 20th century by Norwegian whalers who wanted to use them as food.

"I feel sure they will thrive and become prolific in time, if they are left alone, which would most assuredly be an asset to South Georgia," whaler C.A. Larsen wrote in 1911 of the introduction of the first 10 reindeer from south Norway.

But the plan has backfired.

The cull "is the kind of action that's needed from time to time to correct previous mistakes", said Arild Skedsmo of the WWF conservation group. He also said Norway should act to get rid of its king crabs, introduced to the country from the Pacific, and sitka spruce trees brought from North America.

Eradicating reindeer is a prelude to a harder battle to rid South Georgia of rats, brought 200 years ago as stowaways on seal hunters' ships. The French islands of Kerguelen near Antarctica also have big herds of reindeer, originally Swedish.

Andersen said the reindeer meat would be transported to the Falkland Islands, which has a population of about 3,000. The hope is it will be sold to locals and to visiting cruise ships.