How the Return of Salmon to the Klamath River Shows Us What’s Possible in Wildlife Conservation

Imagine standing on a riverbank as thousands of dead salmon float past, belly-up and rotting in the hot California air. That's the sight—and smell—that greeted people along the Klamath River in September 2002, when 35,000 fish perished there in the span of a few days. They were victims of warm water temperatures and low river levels, both caused by dams and diversions that altered the river’s flow.

This dramatic loss isn’t unique: according to October’s 2024 Living Planet Report, of which I was a co-author, wildlife populations monitored around the world have declined on average by 73 percent in just the last half century. Freshwater species like salmon have suffered even greater losses. Farming and development, like dams, in natural habitats have driven these declines.

But the Klamath story continues to be written. Just a little over two decades on from the massive fish kill, the Klamath became the site of the largest dam removal project in history. Since removal of the lower four dams on the river was completed last month, salmon have surged upstream to parts of the river where they haven’t been seen for more than a century.

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No longer is the Klamath River a tragic example of the global nature crisis; instead, its restoration serves as an inspiring story of how people can work together to repair wildlife habitats. This huge turnaround was made possible through collaboration and unwavering commitment—especially by the region’s Indigenous people. It is an example we can learn from and start replicating across the world.

The scale of that global need for restoration is daunting. The alarming results in the Living Planet Report are derived from the Living Planet Index (LPI), a set of statistics developed by the Zoological Society of London. The LPI provides a broad view of wildlife health across the planet, drawing on data from nearly 35,000 populations of birds, mammals, fish, reptiles and amphibians, across more than 5,000 species. It can also be used to track specific groups, such as migratory fish—from tiny gobies to giant catfish—which have experienced a staggering 81 percent decline since 1970.

Halting—and then reversing—the alarming downward trends in fish and other wildlife populations will require major shifts in how we produce energy and food, and how we implement conservation. The Klamath shows that those shifts are within reach.

The Klamath was once the third most productive river for salmon on the west coast of the United States. Its migratory fish were the primary food—and central to the culture—of the Karuk, Yurok, Klamath and other tribes. But, beginning in the 1920s, four hydropower dams were built on the river, blocking salmon from swimming upstream to spawn and limiting them to a reduced stretch of the river. The expansion of irrigated farming further stressed the salmon through reduced flows and high water temperatures—the factors that caused the 2002 fish kill—and the runoff of chemicals and nutrients.

But from that low point, the opening for recovery emerged. At the heart of the Klamath’s stunning turnaround was the unwavering dedication of the tribes to restore their salmon. Their long-neglected legal rights, cultural commitment, and steadfast efforts made river restoration possible. Collectively, their breakthroughs demonstrate that implementing conservation at the scale necessary to restore wildlife will require a diversity of both leadership and strategy.

First, regulators, conservation groups and tribes negotiated agreements with farmers to reduce agricultural runoff, improve water quality, and balance irrigation demands with water levels in the basin’s lakes and wetlands. That led to the Klamath Basin Restoration Agreement, signed in 2010. That agreement also set the stage for removal of the four hydropower dams, an outcome the tribes had been pursuing for decades.

Another catalyst for removal was the legal requirement that the owner of the dams, PacifiCorp, renew the dams’ licenses, which were set to expire in 2006. In the U.S., hydropower project owners must periodically apply for new licenses through a process that considers options for reducing the projects’ social and environmental impacts. For the Klamath dams, regulatory agencies recommended that license renewal would require the addition of fish ladders to allow salmon to swim above the dams— construction projects that would have been prohibitively expensive. Ultimately PacifiCorp signed a settlement agreement with the tribes, agencies and conservation groups to remove the four dams, which started late last year.

The removal of four hydroelectric dams may seem like a major loss of renewable energy. Thanks to California’s rapid expansion of wind and solar energy generation projects, however, the loss of the Klamath dams—which provided just 2 percent of PacifiCorp’s generation capacity—will be offset many times over. In fact, California’s new renewable capacity added during the dam removal process will be nearly 20 times greater than that of the Klamath dams.

Restoration of the Klamath clearly demonstrates the potential for leadership and resource management by Indigenous people—whose lands encompass 40 percent of the world’s remaining natural areas—and whose efforts will be central to effective conservation in the 21st century.

Further, restoration was only possible through a diverse set of strategies. For centuries, nature conservation has been synonymous with setting aside large tracts of land in national parks or wildlife refuges. The Klamath Basin encompasses six national wildlife refuges, two national parks, and wilderness areas—and approximately two thirds of the basin is in public land, mostly national forests. And yet the salmon—one of the basin’s most important environmental and cultural resources—still found themselves on the ropes. Restoring that resource required agreements on water use, agricultural management and dam removal to restore river connectivity.

Just such examples are sorely needed. In November representatives from 196 countries wrapped up the United Nations Biodiversity Conference (COP16) in Colombia and, while some important agreements were reached, much of the work of setting targets and designing strategies for conserving and restoring nature remains to be done. Reversing the losses of wildlife worldwide will require a diverse set of strategies. Protected areas will remain important, but so will transformations in how we produce energy and food and implement conservation. And while “transformation” may sound daunting, the Klamath’s remarkable turnaround demonstrates that the recovery of nature remains in reach.

This is an opinion and analysis article, and the views expressed by the author or authors are not necessarily those of Scientific American.