Biologists say the sea lions that scoop up fish at the foot of Bonneville Dam on the Columbia River have killed more sturgeon this year than salmon.
Two different species of sea lions like to feast at Bonneville Dam. California sea lions only eat salmon. But Stellar sea lions arrive earlier in the year. While they wait for the spring salmon run to start, they snack on sturgeon.
Biologists with the Army Corps of Engineers estimate that this year, the Stellar sea lions ate about 2,500 sturgeon.
The corps is among several federal agencies that are legally required to work on protecting the Columbia’s threatened and endangered species of salmon and steelhead. The new findings have them concerned about sturgeon, which aren’t under the same federal protection.
Corps spokeswoman Diana Fredlund says the sea lions mainly devoured sturgeon about 3 feet long. Those fish were young adults getting ready to reproduce.
“They spawn multiple times in their lives so that’s one of (the) concerns,” Fredlund said. “As they’re getting these larger sturgeon, they lose all of their children.”
Oregon and Washington have permission to remove and kill California sea lions. But the larger Stellar sea lions are a threatened species, and fisheries managers at the dam are limited to hazing them.