My Yellowknife Now

Salmon caught in Mackenzie River raises climate change questions in the NWT

Arthur C. Green / Vista Radio

Dec 9, 2019
The presence of salmon is increasing in the Canadian Arctic. Salmon used to be infrequent visitors to the Mackenzie River and communities of the Arctic in the NWT, but a recent catch reinforces that climate change is happening.

Brad Wade posted a picture of a salmon on Facebook recently which was caught in the Mackenzie River.

“My class caught a salmon in the Mackenzie River and traditionally they are not found here,” Wade said. “As the rivers in British Columbia (B.C.) become warmer, salmon have to move North to find colder rivers to lay eggs.”

The major issue is that salmon is an invasive species in this area and a major predator, Wade added.

People across the Canadian Arctic are catching more salmon in more places. Salmon may be moving further north due to broader changes in ocean and freshwater ecosystems related to climate change.

Ms. Darcy McNicholl is a biologist with DFO at the Freshwater Institute in Winnipeg. McNicholl has been working on the effects of salmon migration on the waters of the NWT because they are an invasive species.

“All five species of Pacific salmon showing up in the McKenzie River,” McNicholl said “Likely related to warming temperatures.”

McNicholl says there is however already a resident population of Chum Salmon in the McKenzie River.

“They have been there for a very long period of time since the last glaciation, so there is a small population of Chum Salmon that are native,” McNicholl said. “As for the new species of salmon they’re either following their preferred habitat, or they’re following food or both.”

McNicholl says at this stage of her research she is working with communities to monitor the presence of salmon in the NWT and in parts of Nunavut.

“It’s a little too early to say if they have a negative impact or not,” McNicholl said. “What we’re trying to understand is where they’re coming from, what they’re eating and whether or not they’re successfully spawning in the Arctic rivers.”

McNicholl has begun studying the diet of the caught salmon which may have some clues as to why they are headed into Arctic waters.

“The stomach’s that we observed have mostly been empty,” McNicholl said. “Once they migrate into freshwater they’re coming up the NWT rivers to spawn.”

McNicholl says she has studied tissue information from the caught salmon and that has shown that the salmon might be using different sources than some local fish like arctic char.

“It’s a little early to say whether or not they’re a danger to some of the native species,” McNicholl said. “It’s an important study because it’s affecting the fishermen of the NWT.”

McNicholl says there are a lot of places where they used to catch primarily Arctic Char and now the fishermen are seeing a lot more salmon.

“This year has been a particular interest because, in 2019, we’ve had record numbers of salmon across the NWT,” McNicholl said. “So we’ve collected almost 3000 salmon with our program through bycatch of other harvesters, which has surpassed any of the other years we’ve observed combined.”

McNicholl says that the amount of salmon turned over to DFO this year has been phenomenal, it’s an indication of biodiversity and climate change.

“It’s been a phenomenal year for the number of salmon turned in,” McNicholl said. “We’ve also noticed an increase in Sockeye which weren’t very common before. So, using salmon as a tool for monitoring climate change has been very useful.”

McNicholl says she is trying to understand how the salmon might interact with other fish in the NWT.

“Increasing salmon occurrences across the Canadian Arctic reflect underlying changes in the ocean and rivers,” McNicholl said. “Warming temperatures and changing environmental conditions may be helping salmon access and perhaps survive in the Arctic and could lead to salmon moving into new areas.”

Salmon does live with Arctic Char in Alaska McNicholl says and has done so for hundreds of years, however, it’s important that anyone who catches a salmon in the North to speak with DFO.

“It’s a little early to say what seven species of salmon are coming into the Arctic,” McNicholl said. “Which is why it’s been important for us to speak with people and understand what they’ve observed.”

McNicholl says people who catch salmon can reach out to her on the DFO Arctic Salmon Facebook page to submit information.

“We can take either the head of the salmon or the whole salmon and in exchange, they’ll get $25 for the head, or $50 for the whole fish,” McNicholl said. “This will help us answer some of the questions about where they’re coming from whether or not they’re bringing pathogens or diseases and what they might be eating.”

McNicholl says that fishermen can do so at their local hunters and trappers committee offices or in any of the DFO offices.

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