KLAMATH FALLS (AP) - Scientists will place chinook salmon in the waters of Williamson River and Upper Klamath Lake this week to see how they respond, perhaps setting the stage for the eventual return of the sea-running fish to the Klamath Basin.

The year-old salmon will be confined to 2-foot submerged cubical mesh cages that will be submerged in the water by the U.S. Fish and Wildlife Service.

”Essentially they will be captives,“ said Phillip Detrich, field supervisor for the agency's Yreka, Calif., office.

The scientists will evaluate how the water quality affects the salmon as they grow into smolts, young fish ready to go from fresh water to salt water. They also hope to see if there is enough spawning habitat for salmon in the rivers that feed into Upper Klamath Lake. Trout and salmon can usually co-exist, but they might compete for resources if there is limited habitat.

The salmon will be put in the water today and Tuesday and stay there for two weeks. The salmon will then be dissected to see how they fared.

The tests, which will be repeated in spring, are being conducted as federal officials decide whether PacifiCorp, which has a series of dams on the Klamath River, should be required to install ways for salmon to get around the dams as part of a new 50-year license.

Detrich said the agency has a long-standing interest in returning the fish to the Basin, where they haven't been since the first power dam was built on the river in 1918.

In February 2004, when PacifiCorp applied for a new license with the Federal Energy Regulatory Commission, plans for providing fish passage past the dams weren't included. Since then, the application has been reviewed by Basin stakeholders, and the company and stakeholders are working on a settlement. And federal agencies also are vetting the application and could ask the commission to attach conditions to the license.

Detrich said the Fish and Wildlife Service may require that the Portland-based company make changes to its dams to allow for a return of salmon to the Basin. The requirements could include ladders for fish to climb on their way upstream, screens from power turbines and bypass tubes for their swim downstream.

Jon Coney, PacifiCorp spokesman, said the company hadn't heard of the plans to test salmon in the Basin.

”We are curious to see what happens,“ Coney said.