Engineering fish

Americans generally believe that technology poses a significant threat to the world's natural environment, but they also have an abiding faith in the power of technology to solve environmental problems. In the Pacific Northwest this paradox reveals itself in the vast network of dams that impound the region's major rivers, including the Columbia, Snake, Willamette, and Rogue. The dams, numbering in the hundreds, were built during a fifty-year period by the U.S. Army Corps of Engineers, the Bureau of Reclamation, public utility districts, and private corporations. Since the mid-1930s, the dams have yielded considerable economic and social benefits, principally hydroelectric power, flood control, navigation, irrigation, municipal water supply, and recreation.

Unfortunately, the dams also have had a substantial, irreversible effect on the ecology of the rivers that they impound. The paradox arises when the public believes that these effects can somehow be remedied by applying a technical fix. But the dams are firmly in place, their imposing presence permanently blocking the rivers' free flow and, consequently, altering the rivers' natural physical, chemical, and biological features. Thus, earnest attempts at technical remediation - short of breaching the dams, which has been seriously considered - have proven to be largely ineffective, if not more detrimental than the original impacts.

Perhaps the most publicized and disturbing ecological effect - one largely attributed to dams - has been the rapid decline of the rivers' highly valued anadromous fish populations (fish that return to the freshwater rivers from the sea to breed), consisting chiefly of Pacific salmon and steelhead trout. The life history of these fish is complex, with each phase of biological development precisely timed. As adults, the fish migrate far upstream from the Pacific Ocean to spawn in streambed gravel, or redds. There the eggs hatch, releasing larvae that eventually emerge from the redds as fry. Once in the open stream, the fry begin their long journey to the ocean, where they will spend several years maturing to adults.

When the dams were first proposed, scientists and others expressed grave concerns about the fate of anadromous fish. They feared that spawning areas would be inundated or rendered inaccessible upstream of the impoundments, and that fry would be decimated ("sliced and diced") as they passed through power-generating turbines en route to the ocean. In response, the Corps of Engineers and other dam-building proponents assured the public that technical means were available not only to protect the fish, but also to enhance their productivity. These techniques included fish hatcheries, fish ladders allowing fish to bypass dams, fish collection facilities, and other engineering approaches. Unconvinced, the fish-- advocates predicted that these would only become "monuments to a departed race."

By 1990, it was evident that these early predictions were ominously on track. In the Columbia River, for example, the annual number of upstream migrants had declined by nearly 85 percent during the preceding sixty years, dropping from more than 16 million adult fish per year during the 1930s to around 2.5 million adults in 1990. Regrettably, this downward trend continues today despite billions of dollars spent on efforts to rescue the fish from extinction. In his recent book Salmon Without Rivers: A History of the Pacific Salmon Crisis (1999, Island Press), James Lichatowich sadly reports that salmon populations are now extinct in nearly half of the rivers where they once spawned, and that populations in about half of the remaining rivers are at risk of becoming extinct.

In 1962, following severe flooding in Oregon and California seven years earlier, the U.S. Congress authorized the Army Corps of Engineers to construct three large dams on the Rogue River in southwest Oregon. The Rogue originates near Crater Lake National Park along the crest of the Cascade Mountain Range. From its origin, the river flows westerly for a distance of 215 miles before discharging into the Pacific Ocean near the town of Gold Beach. The river is so highly regarded that it was among the original twelve in the United States protected under the federal Wild and Scenic Rivers Act of 1968. (The wild and scenic designation applies only to the river's lower reach, however, which covers a distance of eighty-four miles and flows through the Wild Rogue Wilderness Area.)

The Rogue River is world-renowned for its runs of Pacific salmon and steelhead trout. Between 1929 and 1933, commercial fishermen caught an average of 305,000 adult chinook salmon and about 9,000 coho salmon in the Rogue River annually, attesting to the river's high productivity. The author Zane Grey, who often fished from his cabin on the river, aptly described the Rogue in his 1948 book Rogue River Feud (Harper and Row Publishers): "Deep and dark green, swift and clear, icy cold and as pure as the snows from which it sprang, the river had its source in the mountain under Crater Lake. It was a river at its birth; and it glided away through the Oregon forest, with hurrying momentum, as if eager to begin the long leap down through the Siskiyous. The giant firs shaded it; the deer drank from it; the little black-backed trout rose greedily to floating flies."