Researchers have calculated the probability of foreign species being introduced to the waters surrounding the Norwegian Archipelago as global ocean temperatures rise and more ships sail to the Arctic. By 2100 there will be a sixfold increase in the number of harmful species in the ecosystem there, they said.
The archipelago, known as Svalbard, is the northernmost part of Norway and lies midway between mainland Norway and the North Pole. Ships from distant seas introducing foreign species to new territory is nothing new, but researchers report that the number of nautical stowaways will only increase as warming oceans make it possible for normally low-latitude species to survive in the northern waters.
"For the first time we have shown that in the future the port of departure will be more similar to the port of destination in the Arctic than it is today with regard to climate and the environment," said researcher Chris Ware from University of Tromsø in Norway. "This development will increase the chance of survival for those organisms that could arrive with ballast water or through biofouling," he said, referring to species hitching a ride on the outside of ships.
Ware gave the example of the Red King crab as a possible foreigner with a big impact in the Svalbard waters.
"This is an example of an animal that could change the balance between the current species, as it would become very dominant in the fragile environment," Ware said, adding shore crab and the Japanese skeleton shrimp to the list of potential invaders.
The researchers cite warming waters around the world as a harbinger of foreign species entering the Svalbard ecosystem.
"Already in 2050 the climate around Svalbard will be more similar to the climate found in the ports to the south where ships to Svalbard typically depart from. This increases the risk that introduced species will survive and compete with the original species around Svalbard," Aarhus University said in a statement.
By 2100 there will be a sixfold increase in the number of harmful species in the Svalbard ecosystem, the researchers said.
"We consider our results as an 'early warning' for what could happen, not just in Svalbard but also in Greenland and other parts of the Arctic," said Aarhus senior researcher Mary Wisz.
"The next step is to find out which stowaways will have the greatest chance to survive the journey in ballast tanks or on the ship hulls, and which are most likely to establish breeding populations after arriving in the Arctic. These questions are the focus of our current research.
"Each species has its own physiological characteristics and relationship to the environment, so if we can foresee that some particularly problematic species are at risk of becoming established as the climate warms, we are in a better position to concentrate specific effort and resources to keep them out."
The study is published in the journal Diversity and Distributions.