On September 27, 2013, the Nordic Orion, a commercial bulk carrier owned by the Copenhagen-based shipping company Nordic Bulk Carriers, became the first bulk carrier to cross the Northwest Passage—a route that connects the Pacific and Atlantic Oceans above Canada—arriving off the coast of Greenland after departing from Vancouver, B.C. ten days earlier. The ship was loaded with British Columbian coal, and was able to haul 25 percent more than it could have carried if it had been forced to take the Panama Canal, where ships have to sail higher in the water and carry less. The route, which snaked through Canada’s Arctic waters, saved the shipping company nearly four days and $200,000 by the time the ship reached its final destination in the Finnish port of Pori. This shortcut wouldn’t have been possible decades ago, but because of a reduction in Arctic sea-ice coverage in recent years, ships are now able to navigate more northerly passages, both through Canada’s icy waters, and in Russia and Norway’s northern seas. But cargo isn’t the only thing that they’re transporting: some marine biologists worry that ships carting cargo through the Arctic’s newly opened waterways are introducing invasive species to the area—and bringing invasive species to some of America’s most important ports.

Why is Arctic shipping suddenly a big deal?

For centuries, explorers have been searching for a Northwest Passage—a route connecting the Pacific and the Atlantic; the search for the Northwest Passage was the entire basis for Lewis and Clark’s famed expedition. And they weren’t the first, or the last, to go looking for it. As it turns out, these expeditions were just a bit early: rising global temperatures have caused Arctic waters to warm, decreasing the amount of ice cover. In the past 30 years, the Arctic has warmed more than any other region on Earth. Over that same 30-year period, according to satellite images, Arctic ice cover has declined by 30 percent in September, the month that marks the end of the summer melt season. Arctic ice loss is a problem for global warming, because it creates a kind of warming feedback loop—less ice means more dark water exposed, which means more sunlight absorbed by the water, which in turn leads to more warming.

What Arctic melting isn’t bad news for, however, is the shipping industry, where 90 percent of all goods are moved via carriers. Until recently, ships that wanted to travel between oceans had two primary paths—the Suez Canal and the Panama Canal, both located in warm, tropical latitudes. As warming Arctic waters open up a northern route for shipping, the routes turn out to be more appealing for a few reasons. First, they’re shorter, shaving valuable days off of traditional shipping routes. This means faster turn around for ships, and less fuel, all of which translate into big savings for the industry. Container ships that go through Arctic waters also aren’t subject to cargo limits imposed for certain routes, like the Panama canal. Finally, ships passing through the isolated Arctic don’t need to worry as much about piracy, adding a level of economic security.

An increasing number of ships have been using this new northern network of shipping passages in the past years. In 2013, 71 ships transited the Northern Sea Route, a route that crosses the Arctic Sea along Russia’s northern coast. In 2012, the year of the lowest recorded Arctic sea ice coverage, 46 ships made the same crossing. In 2011, that number was 34. Contrast that to 2010, when just four ships made the journey. Nearly 19,000 ships cross the Suez Canal each year. So the number of ships crossing through Arctic waters is likely going to increase: a 2013 study published in PNAS argued that due to global warming and Arctic ice loss, by 2050 even ships not equipped with ice-breaking hulls will be able to navigate Arctic shipping routes.

So are people just using the Arctic for shipping?

Shipping routes through the Arctic are appealing to shipping companies, but that’s not the only reason the Arctic might see more traffic in the coming years: melting sea ice has revealed natural resources ready to be exploited for profit.

“A lot of those natural resources are submarine, and as the surface ice dissipates, ships can get in there and explore and drill,” explains Whitman Miller, a research scientist and assistant director of the Smithsonian Environmental Research Center’s Marine Invasions Research Lab, who along with his collegue Gregory Ruiz wrote a commentary about invasive species and the Arctic published in Nature Climate Change. “There’s also mining. Greenland, for example, as its ice is melting, is opening up some of the land for mining of rare earth metals, which are really important for a lot of consumer electronics.” So, as Arctic ice melts, there will be two types of traffic plying these waters: a kind that uses the Arctic as a thoroughfare between Pacific and Atlantic ports, and a kind that uses the Arctic as a destination for obtaining natural resources. “All of these things mean invasive species—organisms are going to be moving with these ships,” warns Miller.

Why will Arctic shipping increase the threat of invasive species? Aren’t they transported via traditional shipping routes, too?

Yes, shipping containers and bulk carriers do currently contribute to the spread of invasive species—it’s something that has been irking marine biologists for a long time. Bulk carriers (and ships generally) have things called ballast tanks, which are compartments that hold water, in order to weigh a ship down and lower its center of gravity, providing stability. Ships take in water from one location and discharge it in another, contributing to concerns about invasive species. The zebra mussel, an invasive species that has colonized the Great Lakes and caused billions of dollars of economic damage, is believed to have been introduced from the ballast tank of ships coming from Western European ports. Shipping is already the primary way that invasive marine species become introduced—contributing to 69 percent of species introductions to marine areas.

But Miller and Ruiz worry that Arctic shipping—both through the Arctic and from the Arctic—could make this statistic even worse.

“What’s happening now is that ships move between oceans by going through Panama or Suez, but that means ships from higher latitudes have to divert south into tropical and subtropical waters, so if you are a cold water species, you’re not likely to do well in those warm waters,” Miller explains. “That could currently be working as a filter, minimizing the high latitude species that are moving from one ocean to another.”

Moreover, the Panama Canal is a freshwater canal, so organisms clinging to the hulls of ships passing through have to undergo osmotic shock as saltwater becomes freshwater and back again. A lot of organisms, Miller explains, can’t survive that.

These new cold water routes don’t have the advantage of temperature or salinity filters the way traditional shipping routes do. That means that species adapted to live in cold waters in the Arctic could potentially survive in the cool waters in northern port cities in New York and New Jersey, which facilitated the maritime transport of nearly $250 billion worth of goods in 2008. And because routes through the Arctic are much shorter than traditional shipping routes, invasive animals like crabs, barnacles and mussels are more likely to survive the short transit distance riding along inside the ballast tanks and clinging to the hulls.

Ok, but the Arctic is pretty far from where I live. Why does this matter?

Invasive species are always cause for apprehension—a Pandora’s Box, because no one really knows how they’ll impact a particular ecosystem until it’s too late. In an interview with Scientific American in March of 2013, climate scientist Jessica Hellmann, of the University of Notre Dame, put it this way: “Invasive species are one of those things that once the genie is out of the bottle, it’s hard to put her back in.” There aren’t many invasive species from the Arctic that are known, but one that is, the red king crab, has already wreaked havoc on Norway’s waters; a ferocious predator, the red king crab hasn’t had much trouble asserting near total dominance over species unfamiliar with it. “You never know when the next red king crab is going to be in your ballast tank,” Miller warns.

Invasive species pose two dangers, one ecological, the other economic. From an ecological standpoint, invasive species threaten to disrupt systems that have evolved and adapted to live together over millions of years. “You could have a real breakdown in terms of [the ecosystems] structure and their function, and in some cases, the diversity and abundance of native species,” Miller explains.

But invasive species do more than threaten the ecology of the Arctic—they can threaten the global economy. Many invasive species, like mussels, can damage infrastructure, such as cooling and water pipes. Seaports are vital to both the United States and the global economy—ports in the Western hemisphere handle 7.8 billion tons of cargo each year and generate nearly $8.6 trillion of total economic activity, according to the American Association of Port Authorities. If an invasive species is allowed to gain a foothold in a port, it could completely disrupt the economic output of that port. The green crab, an invasive species from Europe, for example, has been introduced to New England coasts and feasts on native oysters and crabs, accounting for nearly $44 million a year in economic losses. If invasive species are able to disrupt the infrastructure of an American port—from pipes to boats—it could mean damages for the American economy. In recent years, due to fracking technology, the United States has gone from being an importer of fuel to an exporter, which means that American ports will be hosting more foreign ships in the coming years—and that means more potential for invasive species to be dispersed.

Invasive species brought into the Arctic could also disrupt ecosystems, especially because the Arctic has had low exposure to invasions until now. Potential invasive species could threaten the Arctic’s growing economic infrastructure as well, damaging equipment set up to look for natural gas and other natural resources in the newly-exposed Arctic waters.

Is there anything that can be done to minimize these risks?

Obviously one big picture way to stop the spread of invasive species in and around the Arctic is to slow the rate at which the Arctic ice is melting—that means slowing, and decreasing, the rate at which we emit common air pollutants like soot and smog, as well as seriously curbing our carbon emissions over the long-haul.

Realistically, implementing these measures will take serious political and individual action—and in the short term, as long as Arctic ice is melting and allowing ships to pass through, shipping companies will look to those Arctic routes as a way of saving time and money. That means that steps need to be taken more immediately to minimize the possibility of invasive species spreading to and from the Arctic.

One step, Miller explains, could be a wider-implementation of open water ballast exchange, which has been mandatory in the United States for the past ten years. Open water ballast exchange is when a ship replaces ballast water from coastal areas with water from the open ocean. Invasive species tend to be exchanged between one coastal water region and another (such as ports), but they are not likely to survive in deep water ecosystems. The International Maritime Organization (IMO) is also looking into creating standards for the total amount of organisms a ship can discharge in its ballast water, sort of like current standards with smokestacks and pollution—if a ship’s ballast water exceeds whatever limit is imposed, they must treat that water before releasing it. Currently, no standards or onboard treating systems exist, but it’s an attractive option because it would create global standards for ballast water treatment.

Hulls are a more complex problem, Miller explains, but proper hull maintenance could help minimize the threat of things like barnacles or mussels making it to foreign ports. Hull husbandry is also important economically for ships, because it lessens drag through the water, leading to greater fuel efficiency.

As long as the Arctic continues to grow—via shipping, infrastructure and even tourism—Miller and Ruiz argue that it’s in the world’s best interest to give serious thought to limiting the spread of invasive species. “I think, probably more important than trying to pinpoint individual species, is the notion that there’s going to be such a mixing of the biota in a way that’s never occurred before,” Miller notes. “That’s something that we need to give thought to.”