This year, the wildfire season is anticipated to be the second worst in Canada, which may negatively affect organisms in the ecosystem, including fish. The Pacific salmon is an official symbol of B.C., and is highly regarded — especially with Steveston’s 78th Annual Salmon Festival approaching on July 1. With the fire season already affecting parts of B.C., the question remains whether or not the salmon will stay safe during this time.
Although Pink, Chum, and ocean-type Chinook spend a relatively short amount of time in freshwater before navigating out to sea, other stream-types such as Chinook, Coho, and Sockeye spend over a year in freshwater before hitting the beach. In 2025, some of the hatchlings of 2023 are about to move from their freshwater habitat into the Salish Sea.
At the moment, the Salish Sea has relatively good conditions for the welfare of the salmon, but as climate change continues and wildfires keep burning, this may change. Right now, the concern is on the formative years of the salmon and their time spent in the freshwaters of the Fraser Valley.
Historically, B.C. wildfires have disrupted the early development of salmon by smothering their eggs with sediment from the fires, or increasing water temperatures, which stresses juveniles and can lead to population decline in future years. However, the wildfires may have a serious and less visible impact as well.
A recent study by the Department of Earth, Ocean and Atmospheric Sciences at the University of British Columbia reveals the impact of B.C. wildfires on the Fraser Valley’s freshwater. This study shows that the fires impact 16.3 per cent of the variation in water quality. Also, the arsenic levels in the water rise nine months after proximal fires, which can affect the salmon’s growth, reproduction, and immune systems.
There was also a 193 per cent variability in cadmium (highest of the metals tested), which accumulates in aquatic food webs, and can affect kidneys, bones, and respiratory systems.
Levels of copper rise 8-10 months after fires, which affects salmon-type species more specifically by damaging their sense of smell and reactions to danger signals typically felt by pheromones. The data in this study illustrated that these wildfires directly impact the welfare of B.C’s salmon.
However, it’s not just about the dangers salmon could face; it’s the ecosystem around the fish, the culture they bring, and the aquatic emblem of beautiful British Columbia.
