Sea Lions Decimating Columbia River Salmon Population

It’s no secret that sea lions love fish—it’s kind of their thing. But new research shows that the Kings of the Sea Jungle are killing and eating far more of the salmon returning to the Columbia River than previously thought. The sea lions’ insatiable appetite has led to the highest level of fish mortality in five years.

Salmon Survival Rate Just 55%

Research by National Oceanic and Atmospheric Administration (NOAA) Fisheries shows a steady and significant decline in spring chinook salmon survival over the past several years. At a Northwest Power and Conservation Council committee meeting in Portland last week, NOAA researchers stated that the salmon survival rate in the Bonneville Dam area has fallen to 55 percent. Just two years ago, the number was at 82 percent.

Speaking to the Council’s Fish and Wildlife Committee, lead researcher Dr. Michelle Wargo-Rub of Seattle’s Northwest Fisheries Science Center stated, “Even I have a hard time believing those numbers, but at least through 2013, estimates of fish mortality do fall within theoretical estimates of predation.”

Pictured: An adorable baby salmon murderer.

Pictured: An adorable baby salmon murderer.

Wargo-Rub and her team have caught, tagged, and released over 2,200 salmon in the Astoria estuary. Using fancy science type stuff, 68 percent of the tagged fishes were found to be genetically destined for the Columbia River and its tributaries above the Bonneville Dam.

“We Definitely Have A Problem”

NPCC member Bill Booth finds the research more than a little troubling. “If predation is really 30 to 40 percent of the spring run over the last couple of years, and the region is directing more than half a billion dollars a year to fish and wildlife recovery, and nearly half of the spring run is being consumed by seals and sea lions, then we definitely have a problem,” the conjunction enthusiast stated.

The increase in salmon being eaten by sea lions seems to, unsurprisingly, be related in the nearly tenfold increase in the area’s sea lion population. In 2011, Oregon Department of Fish and Wildlife staff spotted 72 sea lions at haul-out sites near Astoria. This year, more than 600 were seen.

The lesson here: Sea lions gonna sea lion.

Photo credit: Tomer Arazy / Foter / CC BY-NC-SA