NEWPORT, Ore. — Two species of fish listed as threatened under the Endangered Species Act are facing a growing challenge in Oregon from hungry sea lions.

The federally protected California sea lions are traveling into the Columbia River and its tributaries to snack on fragile fish populations.

After a decade killing the hungriest sea lions in one area, wildlife officials now want to do so at Willamette Falls, a waterfall in the Willamette River about 25 miles (40 kilometers) southeast of Portland.

The falls represent a new battleground in a bizarre survival war between fish and sea lions in the Pacific Northwest.

Opponents say sea lions are not the only problem facing the fish and shouldn’t shoulder all the blame.