By MARK FREEMAN

State fish managers believe clumping wild chinook salmon in Southern Oregon and Northern California into one species is too broad to justify Endangered Species Act protection.

Oregon's leading salmon experts will make that case to the National Marine Fisheries Service's proposal for threatened status for the region's wild chinook.

NMFS biologists say wild chinook from Port Orford south to San Francisco Bay are a single "Evolutionarily Significant Unit," or ESU, qualifying for protection as a single species.

Jim Martin, Gov. Kitzhaber's salmon advisor, said that large area takes in too many different chinook populations while completely leaving out the upper Klamath River's chinook.

If Upper Klamath Basin chinook warrant individual status -- even separate from other chinook in the same river -- then why not other areas as well? Martin asked.

"There's a growing number of people who are concerned about the size of the ESU," Martin said. "I'm interested in hearing what their explanation for all that is."

Environmental groups such as the Siskiyou Regional Educational Project and Oregon Trout also find fault with the big ESUs.

"I, too, am concerned about the size, but I don't think it should be used as an excuse not to list," said Steve Marsden, the Siskiyou Project's program coordinator.

This clumping issue, plus concerns over the relative strengths and weaknesses of chinook in the area's rivers, are expected to dominate public hearings in Medford and Gold Beach this week on the NMFS proposal.

And that suits NMFS fine.

"These are the kinds of issues we're interested in hearing from people at these meetings," NMFS spokesman Rob Jones said.

NMFS will make a final decision by next March.

A listing could lead to massive changes in commercial and sport fishing in rivers and in the ocean, new priorities for managing Lost Creek and Applegate dams, and habitat protections.

The local hearings are part of 20 that the fisheries service has planned on its March proposals to list 13 different groups of salmon and steelhead as threatened or endangered. The Southern Oregon and Northern California group is one of those 13.

While some runs, such as the Rogue River's wild spring chinook, are down, others, such as the Rogue's fall chinook, are faring quite well.

Genetic testing, life history traits and other factors determine which individual chinook runs are considered part of a single species, or ESU.

NMFS biologists in 1992 defined the agency's criteria for ESUs. At the time, environmentalists argued that the criteria were so broad that the groupings could be used as an excuse not to list some imperiled runs by lumping them with stronger runs in nearby rivers.

In some cases, the opposite has happened. NMFS has proposed listing wild coho, steelhead and chinook in large areas teeming with both strong and weak runs of fish.

Martin said Oregon did not challenge the ESU sizes when wild coho and steelhead were proposed for listing.

But NMFS' approach is an issue now because chinook that spawn in the Rogue, Chetco and Elk rivers are lumped with most Northern California chinook but not with others.

The area does not include wild chinook in the upper Klamath and Trinity rivers, which NMFS has proposed as a separate ESU not worthy of listing.

For decades, concerns for all Klamath wild chinook have been the driving force behind state and federal management of sport and commercial fishing in the ocean.

But this time, NMFS has broken a piece of the Klamath Basin chinook away from the rest.