"We Are Frightened of Pollution and New Invasive Species Taking Over"
4 Jul, 2007 03:51 pm
Terry Callaghan, professor of Arctic biology states that the biodiversity in the Arctic is in grave danger, which could have parallel consequences for the rest of the biosphere.
What were the issues at stake and its conclusions?
The role I played in the discussions was to tell the ministers about the changes which have been occurring here in this part of the Arctic. The ministers were very impressed and a little pessimistic about the changes that are occurring here. I did two things; one was to show a film made by the Arctic Climate Impact Assessment, which we contributed to and played a leading role in. The Arctic Climate Impact Assessment demonstrated the changes, and the projection of the changes in the whole of the Arctic. After the film, I then delved into detail about the changes in this particular area called the Northern Swedish Lapland. So the ministers got both a general overview about what was happening throughout the whole of the Arctic, and very specifically what was happening in the north of Sweden.
In which way is climate change threatening biodiversity in the Arctic region?
Itís threatening biodiversity in many ways, but mainly in the loss of habitat. Also, by the extension of ranges of southern animals, which are strong competitors that displace the Arctic animals and plants. Through observations and a whole series of experiments we see, for example, that the tree line is moving north thereby displacing tundra. In some areas of the Arctic we expect tundra to disappear from the main land with a loss of a whole ecosystem that includes the nesting grounds, breeding grounds, and feeding grounds for hundreds of millions of birds that migrate to the Arctic every year from all over the world. We see sensitive Arctic animals such as the Polar Bear, the Arctic Fox, the Snowy Owl, which are dependant on specific habitats or specific food sources being displaced. For example, the Polar Bear is an animal associated with marginal ice habitats, and as the sea ice cover is reduced, they have less hunting grounds and habitats in which to breed and feed. Species like the Arctic Fox and the Snowy Owl are dependant on Lemmings and small rodents, which traditionally have population cycles in this area of northern Scandinavia have seen a loss of cycles since the 1980ís. Once the Lemming population cycles decrease, then all the predators that specialize on Lemmings, such as the Snowy Owl, populations start to decrease too.
We also see that many species that are very sensitive to the invasion of more competitive species, such as the Arctic Fox for example, is threatened by extension of the Red Fox. We see in the vegetation Mossins and Likins, which are extremely important in terms of biodiversity and ecosystem functioning in the Arctic, being displaced by more aggressive and more competitive species, which respond faster to climate warming.
We find that where there is permafrost melting, the whole ecosystem has changed. In some areas, for example in this area of Northern Scandinavia, were seeing increased water logging and dry land plants diminish to an extent, because wetland plants are taking over. That has consequences for climate change that could affect other areas of the world. Where there is wetland vegetation there is emission of methane, which is a very powerful greenhouse gas. Some of the plants that are extending their ranges because of thawing permafrost are particularly potent facilitators of methane emissions.
With the opening of the sea due to the melting of the Arctic ice sheets there will no doubt be increased fishing and industrial activity in the region.
What danger does this pose to the biodiversity of the Arctic?
There are several aspects. One major concern is the introduction, unknowingly, of invasive species into the Arctic Ocean. If the sea routes are open along the coastline of Siberia, the shipping that will be passing along there will come from warmer oceans and will be carrying organisms with them that could become established in a warmer Arctic Ocean. We are frightened of pollution and new invasive species taking over, which is now very clean and very pristine.
Also, if there is a big development of oil and gas, we expect some spillages that could be disastrous. We expect some major infrastructure development along the Siberian Coast. There will be ports, trading centers, industrial infrastructures, and that will tend to squeeze the tundra. The tundra will naturally be squeezed from the south as the forests invade by moving further north. If we also have human activity extending southwards from the Arctic Coastline, then the animals and plants are going to be squeezed between these two opposing forces. So, habitats will be reduced and increasing fragmented, and disturbance will be increased.
In addition to animal species, how will the indigenous people who subsist on these species be affected?
The traditional food sources will be threatened all the way from reindeer herding on land to hunting seals, as well as Polar Bears associated with ice margins in the north. There will need to be considerable adaptation from the indigenous peoples. For example, here in the north of Scandinavia, reindeer herding varies from the traditional herding in Sweden to quite intensive farming in Finland. We would expect to see a change toward intensive farming, and a loss of culture of indigenous cultures as the pressure on reindeer pastures increases.
On the flip side, with the increased accessibility of the waters due to the melting of the ice will we see the discovery of new species?
Itís a possibility. There was one exciting discovery from West Greenland on land, not in the sea, some years ago. Not only was it a new species, but also it was a new complete new order of organism. Itís more unlikely in the Arctic than in other areas of the world.
How will these changes in biodiversity in the Arctic affect biodiversity throughout the rest of the planet?
The main effect will be one of a loss of specialized species in the Arctic or least a reduction in many of these species. That has to have a global impact. But in terms of the species that you find elsewhere, then it is of course the migrating species that will have an impact on the rest of the world. The marine mammals like whales, which migrate over huge distances, will see their food sources and habitats reduced in the north, which will have implications for their populations further south.
Perhaps the major one is the Birds. I repeat, there are hundreds of millions of individual birds that migrate to the Arctic every year. I believe one statistic is 40-50% of all bird species in Europe visit the Arctic in the summer. If the nesting grounds and the habitats for those birds are reduced, it will have major implications for the diversity in the rest of the world.
Interview by: Christopher Le Coq
Terry Callaghan is the Director of the Royal Swedish Academy of Sciences, Abisko Scientific Research Station in Sweden and a professor of Arctic Ecology at the University of Sheffield.
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