By Philippe Poulin, Fisheries Biologist at the Nunavik Research Centre
Across Nunavik, the importance of Arctic charr needs no explanation. It is not only the most valued fish in the region and one of the main sources of local food, but also closely tied to Inuit identity and traditions. As climate change continues to impact Nunavik, harvesters have noticed significant changes in the smaller rivers that support Arctic charr, particularly lower water levels that can block or delay migration. “All rivers were stronger before,” said Jobie Oweetaluktuk, President of the Inukjuak Anguvigaq.
Reports of drying creeks and shallow sections that are difficult for charr to cross are common in many communities. In Aupaluk, Johnny Akpahatak, President of the local Anguvigaq, reported an unusual sighting in the Nanuit River: Arctic charr were trapped in a shallow pool due to extremely low water levels, and a black bear was catching and eating the fish. “It was not like that before,” he said.
Several environmental changes are affecting river flow. Riverbanks are weakening, and erosion is increasing, adding more material to rivers and making channels wider and shallower. Yet, thawing permafrost is believed to be the main driver; with less frozen ground beneath riverbeds, water drains more easily into the soil. Shifts in rainfall patterns further contribute to these changes. However, studies in the Western Arctic show that rivers respond differently to permafrost thaw, with some even gaining water. Similar studies have not yet been carried out in Nunavik.
Better understanding these phenomena matter because the consequences can be serious. Low water can block migration and limit access to upstream habitats such as spawning grounds and overwintering lakes. Fish may also delay migration while waiting for suitable water levels, increasing vulnerability to predators and rising temperatures. Arctic charr, a cold-water species, avoid water warmer than 16 °C, with temperatures above 24 °C being lethal.
Communities have long taken action to maintain and enhance Arctic charr habitat. In shallow rivers, channels were created or deepened by hand or with heavy equipment. In the southern Ungava Bay, three impassable waterfalls were also blasted to allow the free movement of Arctic charr. These stream enhancement projects have proven to be an effective way to safeguard vulnerable populations.
To better understand the causes of these changes and respond to community concerns, the Nunavik Research Centre launched a new project this year funded by the 2030 Plan for Green Economy and Crown-Indigenous Relations and Northern Affairs Canada.
The Nunavik Rivers Watch Project aims to monitor how Nunavik rivers respond to climate change, with particular attention to the southernmost Arctic charr rivers, where populations are expected to be most vulnerable.
The first step is always listening. Local knowledge holders are interviewed to gather historical observations and information to decide which rivers should be monitored. Small underwater recorders are then installed on boulders or bedrock in valued Arctic charr rivers, providing continuous water level and temperature data. Such water level time series for small rivers do not currently exist in Nunavik, and these new data will support the development of models to better understand river dynamics and predict potential future temperatures and water flows.
During the summer and fall 2025, the project began with Inuit traditional knowledge interviews in Inukjuak and Aupaluk, along with the deployment of water-level and temperature recorders in 10 rivers by the NRC team.
Future steps
While the logger collects data in the rivers, satellites will provide a view from above. Historical imagery from Landsat and Sentinel-2 satellites will be analyzed to provide a broader view of how water extent has changed over the years.
Next summer, additional communities will be visited, and more loggers will be deployed. A drone equipped with a thermal camera will also survey the rivers and identify areas where water temperature is cooler, often caused by groundwater resurgences. These cold-water refuges will be increasingly important for fish as river temperatures are expected to rise in the future.
All data and findings will be shared with the communities that helped shape the project. Maps, photos, and summaries will be provided locally. The collected data will support local understanding of the impacts of climate change on Nunavik’s small rivers and provide practical tools to identify the most vulnerable Arctic charr populations and prioritize stream enhancement projects accordingly.
