This article was produced for ProPublica’s Local Reporting Network in partnership with Oregon Public Broadcasting. ProPublica is an independent, Pulitzer Prize-winning, nonprofit newsroom that produces investigative journalism. Find more stories like this at propublica.org. Sign up for The Big Story newsletter from ProPublica to receive stories like this one in your inbox.

CARSON, Wash. — The fish were on their way to be executed. One minute, they were swimming around a concrete pond. The next, they were being dumped onto a stainless steel table set on an incline. Hook-nosed and wide-eyed, they thrashed and thumped their way down the table toward an air-powered guillotine.

Hoses hanging from steel girders flushed blood through the grated metal floor. Hatchery workers in splattered chest waders gutted globs of bright orange eggs from the dead females and dropped them into buckets, then doused them first with a stream of sperm taken from the dead males and then with an iodine disinfectant.

A man in a yellow waterproof apron slides a fish headfirst toward a machine. Beside him is a stainless steel table of other fish.

Salmon at the Carson hatchery are moved toward a guillotine during the process of harvesting their sperm and eggs, which will be used to breed more than a million baby fish.

The fertilized eggs were trucked around the corner to an incubation building where over 200 stacked plastic trays held more than a million salmon eggs. Once hatched, they would fatten and mature in rectangular concrete tanks sunk into the ground, safe from the perils of the wild, until it was time to make their journey to the ocean.

The Carson National Fish Hatchery was among the first hatcheries funded by Congress over 80 years ago to be part of the salvation of salmon, facilities created specifically to replace the vast numbers of wild salmon killed by the building of dozens of hydroelectric dams along the Northwest’s mightiest river, the Columbia. Tucked beside a river in the woods about 60 miles northeast of Portland, Carson has 50 tanks and ponds surrounded by chain-link fencing. They sit among wood-frame fish nursery buildings and a half-dozen cottages built for hatchery workers in the 1930s.

Today, there are hundreds of hatcheries in the Northwest run by federal, state and tribal governments, employing thousands and welcoming the community with visitor centers and gift shops. The fish they send to the Pacific Ocean have allowed restaurants and grocery seafood counters to offer “wild-caught” Chinook salmon even as the fish became endangered.

The hatcheries were supposed to stop the decline of salmon. They haven’t. The numbers of each of the six salmon species native to the Columbia basin have dropped to a fraction of what they once were, and 13 distinct populations are now considered threatened or endangered. Nearly 250 million young salmon, most of them from hatcheries, head to the ocean each year — roughly three times as many as before any dams were built. But the return rate today is less than one-fifth of what it was decades ago. Out of the million salmon eggs fertilized at Carson, only a few thousand will survive their journey to the ocean and return upriver as adults, where they can provide food and income for fishermen or give birth to a new generation.

Federal officials have propped up aging hatcheries despite their known failures, pouring more than $2.2 billion over the past 20 years into keeping them going instead of investing in new hatcheries and habitat restorations that could sustain salmon for the long term. At the largest cluster of federally subsidized hatcheries on the Columbia, the government spends between $250 and $650 for every salmon that returns to the river. So few fish survive that the network of hatcheries responsible for 80% of all the salmon in the Columbia River is at risk of collapse, unable to keep producing fish at meaningful levels, an investigation by Oregon Public Broadcasting and ProPublica has found.

These failures are all the more important because hatcheries represent the U.S. government’s best effort to fulfill a promise to the Northwest’s Indigenous people. The government and tribes signed treaties in the 1850s promising that the tribes’ access to salmon, and their way of life, would be preserved. Those treaties enshrined their right to fish in their “usual and accustomed places.” The pacts between sovereign nations did not stop the U.S. from moving forward with a massive decades-long construction project in the middle of the 20th century: the building of 18 dams that transformed a free-flowing river into a machine of irrigation, shipping and hydroelectric power.

The dams meet nearly 40% of today’s regional electricity needs. But they decimated wild salmon.

Otis Johnson processes freshly caught salmon at a roadside fish stand last August. Johnson, who grew up on the Warm Springs Reservation, said fishing reminds him of his mother’s tribal traditions and it “keeps me out of trouble. The fish keeps me in a good way and they take care of me. They’re very sacred.”

Many species of salmon are at or near their lowest numbers on record. Native fishermen say their way of life has been stolen from them and from future generations. But the government didn’t invest in making hatcheries better equipped to grow more resilient and abundant stocks. Instead, officials ushered in endangered species restrictions. They knew that hatchery fish were genetically weaker than wild salmon, so they put limits on the number of hatchery fish that could be released into rivers, where they might spawn with wild fish and weaken the gene pool. These restrictions hampered the productivity of the hatcheries, squeezing tribal fishing even more.

In recent years, salmon survival has dropped to some of the worst rates on record. The numbers of returning adult salmon have been so low that dozens of hatcheries have struggled to collect enough fish for breeding, putting future fishing seasons in jeopardy.

Each passing year of poor returns worsens the outlook for salmon. While salmon runs fluctuate from year to year and this year’s returns have been higher than those of the past few years, human-caused climate change continues to warm the ocean and rivers, and the failure to improve salmon survival rates has left the region’s tribes facing a future without either wild or hatchery fish. Federal scientists project that salmon survival will decline by as much as 90% over the next 40 years.