Could an increase in shipping bring new species into Arctic waters?

In the Arctic, connectivity is often described as the relationships between water, species and people. One of the clearest—and fastest-changing—examples of ecological connectivity is the spread of non-Indigenous marine species northward. As sea ice retreats and shipping increases, new biological pathways are opening across the circumpolar region. These pathways are already reshaping the risks, management challenges and future of Arctic ecosystems.

To understand how these shifts are unfolding, The Circle spoke with KIMBERLY HOWLAND, a research scientist with Fisheries and Oceans Canada and one of the authors the Arctic Council’s Marine Invasive Alien Species in Arctic Waters report. She explains how sea ice loss is transforming shipping routes, how organisms can hitchhike their way to the north, and why the Arctic could soon be a new hotspot for biological invasions.

How does climate-driven loss of sea ice increase the movement of ships in the Arctic?

Sea ice loss is increasing the accessibility of the Arctic by opening up new shipping corridors, like the increased use of the Northwest Passage. It’s also extending the length of the shipping season.

In areas that already had shipping, the navigation season can now be longer. Together, these changes are increasing the numbers of ships entering Arctic waters.

These changes in ice conditions makes the region more attractive for extractive industries—mining and hydrocarbon—as well as for tourism, with cruise ships and yachts, and for fishing. All of these activities have increased, especially over the past decade.

What does increased shipping mean for the movements of organisms themselves?

All ships can have biofouling. This refers to organisms attached to surfaces that can be transported, like a ship’s hull. Organisms can also be moved in ballast water that cargo ships take up in source ports to provide stability when they are empty.

There are international measures to deal with this. For example, the International Marine Organization (IMO) has adopted biofouling guidelines to manage the accumulation of aquatic organisms and developed regulations requiring ships to have treatment systems on board. These systems can use ultraviolet radiation or chlorine-based treatment to kill organisms, but the process is not 100 per cent. The systems treat the water as it’s taken on board and, in the case of chlorine, they neutralize the chlorine before discharging it.

Are there particular shipping corridors where the risk of biological transfer is especially high?

The shipping corridors where we see a high level of connectivity and good climate match will be those at greatest risk—for example, between northern Europe and ports in the Arctic, such as Svalbard or northern Canada, or between ports in northern Asia and areas like Alaska.

Alaska, northern Labrador and Hudson Bay also contain habitats that show suitability for a number of invasive species that have the potential to arrive through shipping.

How likely is it that non-Indigenous species introduced through shipping can live in Arctic waters?

If the temperatures and other conditions are such that they can survive, then they may establish themselves. The habitat needs to be suitable—but sometimes species surprise us and survive where we didn’t think they could.

Temperature is really the key element. Species need water at the correct temperature for a sufficient window of time to allow for reproduction and development. Then they need to be able to survive the Arctic winter, under the ice.

As the Arctic warms, we’re getting longer windows of open water. This increases the probability that eventually we will have a window long enough for new species to survive, reproduce and establish.

Which species are on your radar?

We’ve identified somewhere in the ballpark of close to 200 cold-water species that can handle marine waters and that we know can be moved by ships (or have a life history that would facilitate movement by ships). We’ve actually found some of these in ballast water that we’re testing. Having a list of species to watch for is really useful. When you detect one where it doesn’t belong, it’s a red flag.

One example is a type of zooplankton (Eurytemora affinis) that can live in waters ranging from freshwater up to about 40 parts per thousand in salinity (saltier than typical open-ocean water). It’s a very adaptable species and tends to be adapted to cool water.

How might a single introduced species affect Arctic ecosystems?

It depends on the species and what native species are living where it’s introduced. If it has a “niche” similar to a closely related native species, there can be competition. In some cases, if the species are closely related, they can interbreed, and then you end up with hybridization and loss of native species. If the introduced species is predatory, it can cause problems for native prey species.

Green crabs are a good example. They’re very aggressive predators. They out-compete native crabs and reduce native prey, which may affect other native predators and the prey species themselves.

What are the biggest challenges in preventing the movement of new species into a region like the Arctic, where ecosystems—and shipping routes—cross multiple jurisdictions?

The Arctic is a huge, highly connected region, and it’s very remote. Many Arctic communities are small, with limited ability and infrastructure for research and monitoring.

Awareness has increased with Arctic Council interest—there’s been plain-language outreach, and our team has been trying to get the word out about the potential risks. But actually doing monitoring takes leadership and collaboration. Having a coordinated effort across all Arctic states is a challenge.

In Canada, with the large port associated with the Mary River development (a large iron ore mining project in Nunavut), ships are required to take enhanced preventative measures based on recommendations from the Canadian government. They’re required not only to treat ballast water, but also to exchange it offshore before entering Arctic waters. Having broader requirements for enhanced preventative measures like these across the Arctic would be a really good thing.

There is also the Polar Code, but its provisions on invasive species rely largely on existing IMO measures—like ballast water and biofouling guidance—rather than setting out Arctic-specific requirements. Strengthening and applying these measures more consistently across the Arctic would be a major step forward.

The measures that the IMO has implemented are definitely helping, but the Arctic is a more pristine area where we have an opportunity to go further. There are people in the Arctic who are highly dependent on the marine environment for their subsistence—the Inuit, in particular. There needs to be an extra level of protection there.

Awareness is increasing, but prevention and monitoring need to grow with it. The Arctic is still a place where we have a chance to do better.