Jody Illasiak checks his fishing net on the Hornaday River, N.W.T. Photo/Karen Dunmall, DFO

Jody Illasiak was baffled when a salmon first turned up in his fishing net in 2016.

The fisherman had never caught a salmon before in the Hornaday River, a waterway in the Northwest Territories where arctic char spawn.

Illasiak’s surprise soon turned into concern, as he worried what the presence of this alien fish might mean for the river’s arctic char population. The char have provided an important food source for the nearby community of Paulatuk, N.W.T. for generations.

“It’s a pretty dire situation in our eyes,” Illasiak said.

Illasiak has been far from alone in his unease, as fishermen across the Canadian Arctic have been catching an increasing number of salmon in recent years.

Different species of Pacific salmon have been turning up in waters as far east as Nunavut.

Researchers say the appearance of salmon in these places is one of many examples of how the Arctic is rapidly transforming due to climate change. As sea ice declines and water temperatures rise, salmon are able to get to new places where they have not been found before.

In the hope of getting some information about his salmon, Illasiak brought the fish to the Paulatuk Hunter and Trappers Committee, which then turned to the Arctic Salmon Project.

The project, which is run by the Department of Fisheries and Oceans, was launched because of the increasing prevalence of Pacific salmon showing up in Arctic waters. The program’s researchers are hoping to determine where these salmon are coming from and what impact they may have on Arctic ecosystems.

The program relies heavily on fishermen to voluntarily turn in the salmon they catch and offers gift cards in return.

Researchers use the fish carcasses that are turned in to identify the species of salmon. Sometimes residents have only turned over a head, having ate the rest.

“With the samples that have been traded in, we can start piecing together the rest of the puzzle, as to how they ended up there, and where they’re coming from,” said Karen Dunmall, an aquatic biologist with the Department of Fisheries and Oceans, who is leading the Arctic Salmon Project.

She said the participation of local fishermen like Illasiak in the project has been vital in gaining knowledge about the salmon. Illasiak has been working with the Arctic Salmon Project to install water loggers in the river to record temperatures in spots that arctic char spawn.

Dunmall said the first Pacific salmon recorded through the project in the Hornaday River showed up in 2012. Since then, fishermen have caught around 30 salmon there.

Project researchers determined that Illasiak’s catch was a pink salmon, which is typically found in the Pacific Rim. Other species of salmon that have made their way to the Arctic include sockeye salmon and chum salmon.

Jody Illasiak caught this Pacific salmon in the Hornaday River in 2017. Photo/Jody Illasiak.

Illasiak caught his salmon in what he says is a prime spawning area for arctic char. One of his main concerns and those of the community in Paulatuk have been whether these salmon will compete with the arctic char and spawn in the same places.

Illasiak said he worries that the salmon may be an invasive species, but Dunmall steers clear of using that term, as there might be potential benefits to having salmon in the area.

Dunmall said the salmon showing up in the river have not established populations yet and are likely “vagrants” who are exploring and responding to changing environmental conditions. There is no evidence to suggest that salmon have started spawning successfully in the river yet, she said.

She said that it is too early to know what kind of impact the fish will have on the river’s existing fish populations.

“We don’t know right now and it’s because we’re at the beginning of all these changes,” she said.