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 lion like to feast at the fish at Boneville. California sea lions only eat salmon, but Steller sea lions arrive earlier in the year, and 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 Steller sea lions ate about 2,500 sturgeon and 1,293 salmon and steelhead.
California sea lions, the species that began frequenting the Bonneville dam first and has been selectively removed and killed since 2008, ate an estimated 1,067 salmon and steelhead and didn’t eat any surgeon.
The estimates were released as part of a 2012 field report, and are based on more than 3000 hours of observation of the pinnipeds.
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.