Biologist Dave Manson prepares an otter trap as part of the Lower Elwha Klallam Tribe’s river otter study on the Elwha River. For more pictures, click on the photo.

Standing on the Altair Bridge in Olympic National Park, members of the Lower Elwha Klallam Tribe wildlife staff peer into the rushing Elwha River below, trying to find signs of river otters in the riffles.

Suddenly, a couple of smooth brown heads break the surface, one playfully pouncing on the other before they dive back under. A few seconds later, four heads pop up while making their way upriver.

Since starting to track river otters in the Elwha River valley last year, the tribe’s wildlife staff has been busy chasing these elusive members of the weasel family. The tribe wants to know what effects dam removal and river restoration will have on the otters, including the population size, eating habits and den areas.

Tribal staff have been setting live capture traps near otter scat and baiting the cages with fish. When an otter is trapped, it is taken to a veterinarian who surgically implants a radio-transmitting tag into its abdomen. The otter then is released back into the wild. The tag transmits a radio signal that the tribe monitors to track the animal’s movement weekly.

“We’ve been following a female otter who has been using an 8-mile stretch of the river from the upper reservoir above Glines Canyon dam north to the Olympic National Park boundary for the past year,” said Kim Sager-Fradkin, the tribe’s wildlife biologist. “The construction, with all the heavy equipment and loud noise, doesn’t seem to bother her. We have also managed to tag three others in the lower river.”

The biggest surprise the biologists have discovered is that two males from the lower river are frequently travelling to Port Angeles harbor to hang out near the Nippon Paper Industries mill and the old Rayonier mill site.

“Both of these sites are very polluted, so the otters are likely picking up some contaminants,” Sager-Fradkin said. “I expected these guys to head to the Strait, but I was surprised to learn that they go all the way to Port Angeles.”