A genetic analysis has found that the number of salmon returning each year to a river in British Columbia has declined more severely than previously estimated, CBC reports.
Researchers from Simon Fraser University and Fisheries and Oceans Canada analyzed scales from sockeye salmon from the Skeena River that were collected through a program that began more than a hundred years ago. As they report in Conservation Letters, the researchers used that data to model population decline. They found that the number of wild adult sockeye salmon that return to the river is about 75 percent lower in recent years than a century ago.
"I'm hopeful it's a wake-up call to the rest of the province," first author Michael Price, a PhD candidate Simon Fraser University, tells the CBC. "We've been seeing these warning signs that salmon are diminishing and yet … we continue to make decisions that are not in the best interests of salmon."
The researchers in particular noted sharp declines among large-body sockeye salmon populations in the river. This, Price tells CBC, could be attributed in part to selective gill-netting for larger fish.