Salmon are in trouble. In California, the prized king (chinook) salmon is in short supply. In the Pacific Northwest, sockeye salmon have been showing a long-term decline (though that seems to be rebounding.) But there's one species of salmon that has the opposite problem. Pink salmon are booming in such great numbers that they're threatening the stability of the North Pacific ecosystem, says National Geographic.
Too many pink salmon, says James Owen reporting on a new study, are gorging on the food needed by seabirds, causing seabirds to lay and hatch fewer chicks, and fewer chicks to make it to adulthood. The pink salmon, he says, are even hurting other types of salmon by out competing them for food.
It's "an uncommon case of too many fish in the sea," says the report. The study, led by Alan Springer of the University of Alaska Fairbanks, found that salmon eating the food of seabirds appears to be cutting the birds' numbers.
"Very little is known about how open ocean ecosystems work, and the apparent effect on them by salmon, wild and hatchery produced, really must be considered," Springer said by email.