Arctic Plant Invasion The Shoe Cleaner Who Wants to Save Svalbard

As Arctic temperatures warm, the threat of invasive species grows. One path for travelling seeds is on the bottom of unsuspecting tourists' shoes. A young Australian researcher is doing what he can to tackle the problem.

The gigantic polar bear is one of the first things that newcomers to the Svalbard archipelago in the Arctic notice when they arrive at the Longyearbyen Airport. The stuffed giant dominates the baggage claim -- for Svalbard's ever-increasing number of guests, a first glimpse of the majestic natural beauty that awaits them outside.

It is also meant as something of a warning. After all, the bears are dangerous and are among the world's largest predators. With a population of 3,000, there are more polar bears on the archipelago than humans, say researchers.

But not far away from the bears sits 26-year-old Chris Ware, waiting for his moment. When visitors are done checking out the local taxidermy, Ware moves in -- asking to look at the soles of new arrivals' shoes. "Free Shoe Cleaning" announces a sign made by the red-headed Australian, who studies at the University of Tasmania.

Travellers tend to be confused at first, but Ware has his explanation ready. "The idea is to prevent the introduction of new plants species that could spread uncontrollably, damaging the sensitive ecosystem of the archipelago," he said. Visitors carrying seeds in the grooves of their walking shoes to Svalbard without knowing it could create grave ecological problems. "Once the new species are here, there is practically nothing that can be done about it."

Scientists know of a total of 165 plant species that grow in Svalbard -- located about halfway between Norway and the North Pole -- although there may be more on the less-studied eastern and northern parts of the archipelago. All of them have developed strategies enabling their survival in the bitterly cold Arctic environment. Even in the short summer season they grow very slowly and generally only reach a height of just a few centimeters. There are no upright trees, only a type of horizontally growing birch that coils twists along the cold ground.

Ware's worries are not unfounded. Humans have already introduced about 20 new plant species to the islands, according to Inger Greve Alsos. Alsos is a professor at the state-of-the-art University Centre in Svalbard (UNIS) which keeps a database of all the plants on the archipelago. One of the unwanted species on her list is the wild radish, spotted near polar research station in Ny-Ålesund in north-western Svalbard. How it got there nobody knows.

'Dirt Almost Always Contains Seeds'

In the airport, Chris Ware sets to work with his blue brush and spade to prevent more alien species from being tracked in. "Dirt almost always contains seeds," he said. "Sometimes it is one, sometimes it is 30 or 40." Everything he scrapes off incoming shoe soles lands in a white plastic tub. Ware collects barely five grams of imported dirt per traveller.

The Australian numbers his soil samples and brings them to a neon-lit laboratory on the ground floor of the nearby UNIS facilities. Ware studies his haul under a microscope. "So far I've cleaned 300 shoes," said the young researcher with pride. Given the some 30,000 tourists who make their way to the islands every year, it is more of a symbolic number. But Ware says he is, for the moment, more interested in understanding the magnitude of the threat -- one which is also well known in the Antarctic.

The shoe sole seeds are to germinate for the next few weeks in a greenhouse that simulates the conditions of the Arctic summer. Ware predicts about 1 percent of the seeds will survive the harsh conditions. But the northern-most part of the world gets warmer by the day, so more types of plants may be able to survive each year. This development is potentially deadly for native plants.

In the past, Svalbard has in fact benefited from immigration of new plant species onto the islands, says Alsos. During the last Ice Age, the ice cover was so thick that hardly any species survived. After the melt, the island had to be colonized anew.

Alsos has conducted genetic research to find out how vegetation returned to the islands after the ice disappeared. She has found that it had nothing to do with migratory birds from Scandinavia, as was originally believed. Rather, the plants came over the ice from northern Russia.

Migration by Sea

Two Californian scientists recently reported another, ongoing wave of immigration into the Arctic: that of sea animals. In an early-August article in the journal Science, Geerat Vermeij and Peter Roopnarine document a massive ocean migration that could be even more comprehensive than that occurring on land.

Numerous species from the North Pacific are pushing toward the ever-warming Arctic, according to the scientists. From there, the animals can eventually cross into the Atlantic Ocean. At least 77 species of mollusks and a third of the shellfish in the Bering Straits between Siberia and Alaska have the potential to spread in such a manner. Possibly the number of travelling species could be higher still.

In the past, there has been one other migration of comparable size -- in the Pliocene epoch approximately 3.5 million years ago. At that time, the coastal areas surrounding the Arctic Ocean could have been free of ice.

But the newly mobile animals don't constitute a huge danger for species in the Atlantic, according to Vermeij and Roopnarine. They expect that domestic and immigrant species would intermingle peacefully.

Ideally, this would also be the case with new plant types on Svalbard, explains Chris Ware. Ideal, but unlikely. "Many new species simply grow, but others can turn whole habitats upside down," he said. The latter are the targets of Ware's shoe cleaning intervention. Depending on his findings, Ware will make a pitch to Svalbard Governor Per Sefland -- to oblige locals and incoming visitors to do their part and clean their shoes.

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