Salmon crisis is a kaleidoscope of complexity

  • ANCIENT SURVIVOR: Chinook salmon

    Allan Solonsky photo
 

My mother was fascinated by the Columbia River and the fate of the salmon. This was partly because I work with these issues, but also because they have the kaleidoscopic complexity and human idiocy that all really hard problems have. She thought those were the only problems worth our time.

From her home in Salt Lake City, she would call and probe for the latest developments, and I, sitting in Portland, would try to fit my answers into the cramped space of a telephone call without losing too much texture. I left things out, thinking we would settle down to talk at length when we next saw each other. But we ran out of time. Not long ago, she died unexpectedly. So here is another chapter, dedicated to her.

Columbia River salmon have been in decline since the early part of this century. When this first became noticeable, people began limiting the harvest. Later, they built fish hatcheries and installed ladders to allow returning adult salmon to swim past the dams. Still later, the Army Corps of Engineers barged juvenile fish downriver and placed mechanical screens in front of powerhouse intakes to keep fish away from turbines. In the 1980s, instream-flow programs began on the main stem of the Columbia, and hundreds of millions of dollars were invested in habitat repair, fish-friendlier hatcheries and other measures. Yet, by the late 1980s, salmon were becoming extinct.

When Snake River salmon were listed under the Endangered Species Act in 1991, many said it was time for a stem-to-stern re-evaluation of what we were doing. Oregon Sen. Mark Hatfield asked the National Academy of Sciences to appraise the science underlying salmon recovery. In 1995, the Northwest Power Planning Council asked another group of independent scientists to assess the council's salmon program, which had proposed drawing down reservoirs on the lower Snake.

The science reports came out in 1995 and 1996 and said much the same thing: By focusing on individual populations, we were missing the point. Species are part of ecological communities. They will do well only if the ecological systems they are part of are working. Technology, no matter how ingenious, is no substitute for a healthy ecosystem.

What might that mean in practical terms? For one thing, they said, we needed to think about the overall structure of salmon populations. In pre-development times, most salmon spawned in the broader, shallower alluvial reaches; places where the rivers widened and channels braided; where rivers could flood and deposit gravel; and where ground and surface water could connect and establish habitat that bred microorganisms, insects and the other basic components of a food chain.

For salmon, these were the garden spots, and they became the core of the big, pre-development salmon runs, mainly in the main stem of the Columbia and in the lower stretches of major tributaries.

Spawning grounds in higher tributary areas were more spartan. The farther from the alluvial core, the sparser the food supply and the narrower the ecological niche. Strength came from interaction between strong core areas and diverse satellite populations, any few of which could be lost without hurting the whole.

If a satellite population were wiped out by a mudslide, it would be recolonized from the central core. If a core population thinned, it could be fed from the edges. The bigger the core, the more diverse the satellites, the more resilient the population.

In the 1980s, we had come to think of salmon as headwater spawners, fish that come from mountainous areas of central Idaho, Oregon and Washington, often wilderness areas of great beauty. But that was not necessarily because it made ecological sense.

We focused recovery efforts on headwater fish partly because they were almost the only populations we had left, and partly because people have always preferred the rich taste of spring chinook. Ecological theory suggests that even in our concern for these surviving headwater stocks, we should recall the core populations that stabilized salmon over the millennia and build recovery around them.

The problem with basing salmon recovery on core populations is that people and salmon share this preference: Most would settle in productive alluvial country. Towns like Portland, Yakima and Pendleton grew up in the lower, alluvial reaches of major tributaries. Irrigated farming and grazing are in alluvial plains adjacent to tributary rivers. Big dams were built in the river's main stem, where they inundated or blocked a great deal of alluvial habitat. Salmon were pushed out of alluvial areas by human settlement. Now, the salmon that don't come from hatcheries are likely to spawn in headwater areas.

Some alluvial populations remain. Bright fall chinook spawn in the last free-flowing stretch of the Columbia, upstream of the Columbia-Snake confluence in south-central Washington. The brights are now the biggest naturally spawning segment of the Columbia runs, one of the few populations that might still serve as a core.

One of the ironies my mother would appreciate is that they spawn in the Hanford Nuclear Reservation, part of the Northwest's contribution to the Manhattan Project and the site of stored nuclear waste that is expected to seep into the Columbia some day. Nonetheless, if we are looking for a core area on which to build, the Hanford Reach area is probably it.

But if so, how would we do it? Would we open up more alluvial habitat for the Hanford brights by lowering the reservoirs in the main stem of the Columbia? One of those dams, John Day Dam, anchors the big electric transmission line to the Southwest. If we lowered it, how would we supply voltage stability to the line? Could barges navigate the Columbia in the absence of these dams? If not, would we sacrifice navigation from there on up, or would we merely lower the reservoirs to intermediate levels in the hope that we can have more alluvial habitat and transportation?

Would we try to rebuild core populations in the lower alluvial reaches of tributaries that are now drained dry in irrigation season? What would that mean for the agricultural communities that straddle these tributaries? These are not small questions, and they won't be answered solely in deference to ecological theory.

There's yet another complication. Because the first ESA listings early in the decade were in the Snake River, much of the debate over the last eight years has centered on the Snake and on whether to breach the lower Snake River dams. But this latest science makes us ask whether this is the right focus. Is the lower Snake a potential core area? If we took out the lower Snake dams, would we increase alluvial habitat, or just expose steep canyon walls? Could fall chinook spawning in the lower Snake be an important core population? Or are we compelled to focus on the Snake simply because the law requires it?

So that's it. Another twist of the kaleidoscope, more dilemmas. As in my last call to my mother, I'm still looking for answers.

John M. Volkman is a senior policy advisor with the National Marine Fisheries Service in Portland, Oregon. These views are his and not those of NMFS or the federal government.