Oregon biologists attempting to save the Willamette River's sharply declined winter steelhead run are facing a new twist in their vexing battle against fish-hungry sea lions at Willamette Falls.



The river has seen an unusual influx this winter of large, sturgeon-eating Steller sea lions.



Anglers from the falls to the Portland harbor report watching the carnage.



"Sturgeon are on our radar," said Shaun Clements of the Oregon Department of Fish and Wildlife. "We have seen up to 10 Steller sea lions at the falls, which is more than typical."



Steller sea lions, twice or more the size of California sea lions, have been in the Willamette in the past, but only a few.

Stellers easily kill and eat large, spawner-sized sturgeon such as those living below Willamette Falls.



"It's been a bit of a surprise," Clements said. "We'll have to have that (sturgeon) conversation pretty soon."



Frustrated department biologists are attempting to deal with California sea lions at the falls. They've warned the smaller Californias threaten extinction of a sharply reduced winter steelhead run at the falls.



Steelhead numbers are dwindling for as-yet unexplained reasons, but when the numbers drop this low - the total count into the valley is still well below 1,000 - the sea lions have a dramatically increased impact.



Clements said the department has been trapping California sea lions for two weeks and has transported three to a beach south of Newport. One returned in three days, one in six and the most recent, taken there last week, hasn't been reported back yet, he said.



While biologists expect the Californias to return, they said even a few days may give some respite to steelhead headed for the fish ladder at the falls. Sea lions aren't particularly trap-shy, Clements said, and will be re-taken to Newport whether or not they've already made the trip.



The Steller sea lions, meanwhile, aren't targeted.



Clements said their larger size and inherent stubbornness make them much more difficult to trap and handle in the California-sized traps below the falls.



"Even at Bonneville Dam, where have more staff and larger traps, we only brand a very limited number," he said. "And in most years, none at all - despite trapping on average a dozen per night."



Oregon and Washington have permission to kill offending sea lions, but only those proven to target salmon and steelhead.

A bill is moving slowly through Congress to relax restrictions in the Marine Mammal Protection Act.

Among its provisions is the addition of sturgeon to the list of damaged species.

The department's updated report on sea lions vs. fish at Willamette Falls is found online at: dfw.state.or.us/fish/sealion/.