The conditions that have led to a population explosion of salmon in the North Pacific, could also be factors in a perfect storm to decimate wild salmon species, according to new research from Simon Fraser University and University of Washington scientists.

The research team found that 750 million pink, chum and sockeye returned to their freshwater homes to spawn in 2005, the highest number recorded since scientists started counting in the 1950s. However, they also found that at least 20 per cent of those adult salmon were from hatcheries.

Randall Peterman, an SFU professor and Canada Research Chair in Fisheries Risk Assessment and Management, said stronger hatchery salmon populations now means they might be able to out-compete their wild cousins for food and resources in the future.

"The ocean is always changing, and current favourable ecological conditions for salmon will not last indefinitely," warned Peterman in an SFU press release. "Unless international agreements are developed to manage hatchery production levels across nations, hatchery salmon may dominate in the North Pacific, when ocean conditions deteriorate."

Colleen Kimmett reports for The Tyee.