Mario Tamburri, a marine scientist and director of the Maritime Environment Resource Center at the University of Maryland Center for Environmental Science, has been researching survivorship and reproduction of organisms likely to be transported by ships by mimicking the conditions of shipping traffic. New colder, shorter routes afforded by the retreat of ice help invaders, such as mussels, barnacles and crabs, on a biological level, Tamburri says. Cold water slows metabolism of organisms, which can sustain themselves in low food conditions. “It’s like putting your groceries on ice,” he says.
Shorter routes also mean more organisms either attached to the hull or in ballast water are now more likely to survive the journey. Previously, the high heat and lack of light of longer trips outside the Arctic killed them off. “When ships now transport goods through the Panama Canal, for instance, through warm water and freshwater, natural barriers to invasive species are built into the shipping routes,” Tamburri says. “In the Arctic, those barriers go away.”
Ballast water and bivalves
Murmansk, Russia, a leading global port and the largest city north of the Arctic Circle, is one area that ice-free routes will likely open up further this summer. As more ships exchange ballast water for cargo, native species in places like Murmansk can quickly lose out against new species that have no checks and balances, such as marine species like bivalves that can be dispersed by larvae in ballast water as well as cold-water adapted adults, including green crabs.
Lewis Ziska, a plant physiologist with the U.S. Department of Agriculture’s Agricultural Research Service, says that once introduced, a new species can outcompete everything that has evolved over millennia. Although some nonnative species are innocuous, others thrive because there have no predators. Nothing controls them in the natural system, and they are better at filtering food out of the water than their native cousins. “Invasives use up the lion’s share of resources, and whatever biodiversity that was there falls apart,” Ziska says.
When new interlopers take hold, one or two tend to become very well suited for that environment and dominate it. The natural biodiversity diminishes, Ziska says. Scientists are beginning to catalogue and classify native and nonnative species at ports near oil facilities in Alaska. No large obvious invasions by marine traffic have occurred yet in the high latitude environment but Ziska and others scientists say no one can be sure. Scientists are only now beginning to look closely.
“We weren’t expecting the Arctic to change this quickly,” Ziska notes, adding that the implications for not only human traffic but also for biology are worrisome. “It’s basically opening up the entire Arctic region as a huge playground for invasive species. New things, new biological organisms are going into the area where they have never been seen before. The consequences of that are, quite frankly, are completely unknown.”