Since mid-July, Fisheries and Oceans Canada has reported that approximately one million chum salmon have migrated into the Yukon River from the Bering Sea. Despite this surge, experts caution that the rise in numbers does not necessarily indicate an overall recovery for this specific salmon species.
In 2020, a concerning decline in chum salmon numbers was recorded, leaving researchers puzzled about the sudden increase this year. Sebastian Jones, a wildlife analyst at the Yukon Conservation Society, expressed unease over the lack of understanding regarding these fluctuations in salmon populations.
The proportion of Canadian-origin salmon among the returning fish is currently around 12%, falling below the typical range of 20-30%. While this figure remains low, Jones noted an improvement compared to recent years, with an expectation of 100,000 chum salmon crossing the border, up from 25,000 last year.
Jones emphasized that the current numbers, while better, are still below the desired levels of 150,000 to 250,000 chum salmon entering the Yukon. Stephanie Peacock from the Pacific Salmon Foundation highlighted the significance of chum salmon as a vital nutrient source later in the fall, alongside chinook salmon, the other returning species to the Canadian side of the Yukon River.
Both chum and chinook salmon populations have faced declines over time, with the decline in chum salmon being particularly alarming due to its rapid pace compared to the gradual decrease seen in chinook salmon since the 1990s. Researchers are investigating the Bering Sea ecosystem, where the salmon begin their upstream journey, to understand the impacts of factors such as rising water temperatures and industrial trawl fishing.
While cautiously optimistic about the recent increase in chum salmon numbers, Peacock stressed the need for continued vigilance, considering the broader historical decline of these salmon populations. The experts advise a balanced approach in assessing the situation and acknowledging the persistent concerns for Yukon chum salmon.