By Doug Esser
The Associated Press

Fossils reveal Pacific salmon have been around about 6 million years, surviving volcanoes and ice ages.

But in the past 150 years they have disappeared from a third of their range in California and the Pacific Northwest and continue to be sold down the river, David R. Montgomery writes in King of Fish: The Thousand Year Run of Salmon.

A professor of geomorphology at the University of Washington in Seattle, Montgomery studies how streams and rivers evolve. That angle offers fresh insight into the troublesome waters in which salmon swim.

He notes, for example, how in the Olympic National Park giant trees still occasionally fall into the Queets River. They aren't cut up for lumber or firewood or removed by the Corps of Engineers. As a result of the big obstructions, the current scours deeper pools of water. Big pools create room for big fish. Many rivers without such obstructions have fewer pools - and fewer chinook and coho.

Perhaps the biggest contribution of King of Fish is history, not science. Montgomery reminds us that those who ignored the lessons of Atlantic salmon in Europe and New England were doomed to repeat the mistakes in the Pacific Northwest.

Overfishing, dams, deforestation and pollution depleted runs that people thought were practically infinite.

"Just like Britain, New England traded its salmon for mill dams and factories. The Pacific Northwest was even quicker to cash in its bounty of salmon in a waterborne gold rush," Montgomery writes.

"The accelerating pace of technological development compressed the time frame over which these market and cultural developments occurred," he writes, from a thousand years for English salmon to one century for the salmon of New England to decades for the Columbia River runs.

The commercial extinction in many rivers was often the incidental result of a series of small changes over time and distance, Montgomery writes.

Logging, mining, farming, irrigation, navigation, hydropower, urbanization simply claimed a higher priority on rivers and streams than fish. Between 1933 and 1975, the government spawned 18 dams on the Columbia River system.

"Extinction by a thousand cuts, whether deliberate or incidental, is still forever," Montgomery writes.

Given cool water, clean gravel, food and protection from predators and overfishing, salmon will thrive like weeds, he writes. Yet, the net result is that salmon runs to Northwest rivers are just 6 percent to 7 percent of historic levels.

King of Fish is easy to read and full of interesting facts. Montgomery writes with the authority of a scientist but without jargon. Unfortunately, he offers no miracles. His proposals aren't new: Reduce fishing pressure, remove barriers to migration and protect habitat.