Are sharks and other predators gnawing down the average size of returning Chinooks?

摘要

Older Chinook salmon may die in the ocean more often than previously thought, according to a life cycle simulation created by Alaska researchers.Newly released results help explain why Chinook salmon returning to Alaska's rivers have become smaller and younger in recent years.In a study published in the journal PLOS ONE, researchers at the University of Alaska Fairbanks found that a higher than expected death rate of older Chinook salmon while at sea would explain the patterns observed in recent years.If older salmon are in fact dying at unexpected rates, the phenomenon may reflect sharks and other predators targeting bigger salmon, they said.