A lot of things happen every odd-numbered year in the fall around Squamish. Every odd-numbered year in the fall, many fish come up the Cheakamus River.
Eagles cluster along both sides of the river, bears come into the area to feed, and angling activity increases.
At the end of the season, the river receives a large influx of life from the ocean. So big is the influx of fish that scientists and river managers are getting ready for possibly having another spectacular year, like the one in 2025.
Scientists estimate that millions of fish could enter the Fraser River system, including hundreds of thousands in the Cheakamus River. But it isn’t just the fish that are important.
After spawning, pink salmon do much more for the river.
Pink salmon support far more than anglers
Pink salmon are one of the three smallest species of Pacific Salmon found in British Columbia and typically weigh less than 2.5 kg (5 lbs). In spite of being small, pink salmon have a very significant impact on the ecosystem.
Each time they migrate upstream from the ocean to spawn, they carry marine nutrients inland.
The carcasses of pink salmon provide food for eagles, bears, and many other species within the river system.
Local fishing guide Clint Goyette states that pink salmon make a substantial contribution to the overall health of the watershed.
The benefits extend far beyond pink salmon themselves. The biomass brought back into the river systems provides advantages to bull trout, rainbow trout, cutthroat trout, birds, and mammals.
Therefore, a good run of pink salmon may affect other species besides itself.
Storms can turn spawning channels into traps
Protecting these fish has become more challenging in recent years. Major storms are becoming more common during the spawning season.
Large amounts of water can be moved quickly downstream via atmospheric rivers.
However, when these events pass, there is a rapid drop in water level. These variations in flow can cause serious issues for spawning fish.
Side channels along shallow margins may appear safe during periods of high water. When water levels drop rapidly after storms, those channels can become isolated and trap fish.
To mitigate this issue, BC Hydro has implemented additional surveillance measures in addition to regular patrols of the river.
BC Hydro crews monitor side channels, identify hazards, and work with the Squamish Nation and other stakeholders.
Dam operators manage river flows while balancing drought conditions, storm storage, fish habitat, and electricity generation. All of this effort goes towards a seasonal event which takes place according to a relatively predictable schedule.
Pink salmon continue to attract attention from anglers, according to BC Fishing Journal.
Why it only happens every other year
During odd-numbered years, large quantities of pink salmon migrate upstream in the Cheakamus River.
Following spawning in the river, pink salmon eggs remain in the gravel until spring. Juvenile pink salmon then move downstream toward the estuary and enter saltwater, where they spend about 18 months before returning upstream to spawn.
Because pink salmon have a 2-year life cycle, the two populations alternate spawning cycles. Major returns of pink salmon occur during odd-numbered years in the Cheakamus system.
This is why we expect major returns of pink salmon in 2025 and again in 2027.
Red isn’t the only thing that changes
Pink salmon responsible for giving certain sections of the river their reddish coloration are part of that odd-year cycle.
Male pink salmon have developed distinctive humps called “humpies” prior to migration back to freshwater to spawn.
Millions of pink salmon gather in spawning areas throughout late summer and early fall, where females deposit eggs and males fertilize them before completing their life cycle. Two years later, the cycle begins again.
Read the whole thing?
Get the week's signal, not the noise
Our sharpest reporting on energy, climate and nature — free, once a week.
