Study shows declining sockeye salmon diversity in Skeena River
A study from Simon Fraser University found that the total number of wild-born sockeye salmon in the Skeena River has declined by 69 per cent over the last century, while population diversity amongst sockeye has decreased by 70 per cent.
Researchers studied old fish scales from 1913 to 1947 to learn about sockeye in this time period, which they then compared to modern samples.
They identified 13 genetically distinct sockeye populations, which each contain similar character traits.
They found that 12 of them have been declining in numbers, while the population from the Babine River has increased significantly due to artificial spawning.
SFU Biology PhD student Michael Price is an author of the study. He says the total number of Sockeye in the Skeena is similar to what it was one-hundred years ago, but only because artificial spawning has significantly increased the amount of sockeye from the Babine River.
"When you break that down and realize that 70 or more per cent of those fish are actually going back to one place that artificially produces those fish and these wild populations have continued to diminish year over year, that's where the great concern is."
Price warned that a less diverse sockeye portfolio will struggle to adapt if it's environment changes -- and that climate change could be a threat to Sockeye populations that can't survive in warmer waters.
"We just have individuals who have less ability to adapt. There's less variance in that population to adapt to whatever changing environments are coming and have been coming for a while, we're in the presence of climate change now."
He also warned that another consequence of decreased sockeye diversity is food insecurity for local ecosystems as well as First Nations communities who rely on the fish for food.
As for what's caused these declines, Price pointed to human activities such as fishing and habitat destruction. However, he also said that it's up to humans to put in the effort to preserve sockeye populations.