Native American folklore has it that salmon were once so abundant in America’s rivers, people could walk from one side of the river to the other on their backs when they spawned.

Overfishing and declining habitat made such stories almost unbelievable in this day and age. But this year, the thought of walking on the backs of salmon may be a lot more believable for those who need to see it to believe it.

“This is that year with pink salmon” in the Nisqually River, said David Troutt, the Nisqually Indian Tribe’s natural resources director.

The pink salmon population in the river is estimated to reach one million in the coming days.

“People are going to see fish all over the Nisqually Watershed,” Troutt said. “The next two weeks is going to be really a once-in-a-lifetime kind of opportunity to see fish.”

The fish are being counted at a weir on the river set up by the tribe in July to remove hatchery salmon from the river to aid recovery of Chinook salmon, which isn’t thriving as well as pink salmon.

While the meteoric rise of the pink salmon marks great progress in the restoration of salmon in the river, it also poses troubling questions about the health of Puget Sound, Troutt said.

Standing on the shore of the Nisqually River last week, Troutt looks out over the weir, which extends from the Thurston County shore to the Pierce County shore, with machines operating on each side.

“We’re running both sides continually … because the fish are just coming strong,” Troutt said.

The fish enter gates into a trap, which funnels the fish into a “giant archimedes screw,” then lifts the fish and water into a fish tank at the top. Every time they work the trap, they handle about 500 fish, Troutt said. The traps can handle about 1,000 fish at a time.

The extinct Nisqually Chinook salmon hasn’t existed since about the 1960s, a casualty of overfishing, hatchery practices, hydroelectric operations and habitat issues, Troutt said.

Over 30 years, the state and the Nisqually tribe replaced the Nisqually Chinook with hatchery-bred Chinook salmon from the Green River, managing the fish in a hatchery system since the wild fish were gone.

In the 2000s, the federal government said the hatchery salmon weren’t good enough.

They wanted to bring the Nisqually

Chinook back from the dead.

In 1999, the federal government listed the Pacific Chinook salmon as threatened. They said because the Nisqually River provided a high-quality habitat, it was critical to recovery.

The idea was to populate the Nisqually River with the threatened Puget Sound Chinook until they were self-sustaining. As they gradually adapted to the conditions of the Nisqually River, they would eventually become a new breed of Nisqually Chinook, Troutt said. There are 84 miles of the mainstream Nisqually to the Tacoma projects, the upstream boundary for salmon. Of that 84 miles, 75 percent is in permanent stewardship.

“The bottom line is the habitat in this watershed is better than it’s been in 100 years, so there’s an opportunity to have a fish again become a Nisqually Chinook and if we allow fish to spawn naturally and be subject to all the selective pressures that a natural fish would be, over time this fish will adapt and become a Nisqually fish,” Troutt said. “So the goal with this project is to remove that hatchery component and allow the natural fish upstream simply to adapt to the Nisqually River and become wild over time.”

Troutt said pink salmon, and the similar chum salmon, are considered “simple” salmon species — they both feed on plankton and leave Puget Sound quickly for the ocean. Both salmon species are flourishing, with pink salmon soon possibly hitting the one million mark.

While having that many fish helps feed the ecosystem, a simple species dominating the ecosystem is troubling, according to Troutt.

Chinook, coho and steelhead salmon represent the more “complex” side of salmon. They eat other fish and spend more time in Puget Sound before they leave for the ocean.

“We’re concerned that this is yet another indication that Puget Sound is changing and that it’s much more supportive of simple life histories than it is of complex life histories,” Troutt said. “And that’s a problem. Puget Sound is becoming less robust.”

Troutt explains that “varied and robust” ecosystems with many different species and a variety of life history patterns are more likely to weather challenges caused by climate and habitat changes.

Simple ecosystems, dominated by simple species with simple life histories, are less robust and are more susceptible to “boom and bust” cycles caused by changes in climate or habitat.

“It’s just a very different Puget Sound than we’ve ever seen before,” he said.

A number of factors are contributing to the degradation of Puget Sound, according to Troutt. One is increased plankton blooms, which may contribute to the increased pink salmon population. Another is the loss of much of the herring population, a major prey base for salmon. The population is 10 percent of what it was 20 years ago because of lost habitat.

“Puget Sound shorelines are being impacted because when people move in and want to live along the shorelines, they’re armoring their shorelines,” Troutt said. “They’re putting in docks and bulkheads and all that affects the beaches, which affects the herring and candlefish and other species that depend on it.”

It’s necessary to preserve that habitat to make Puget Sound robust again.

“We’ve got to restore habitats where that’s possible and we’ve got to think about other strategies to make habitat more suitable in areas where it’s already been so damaged that it’s not recognizable anymore,” he said.

The challenge is figuring out how to do that when more than two million people are expected to move to Puget Sound in the next 20 years.

“Thinking about how we manage our shorelines is absolutely critical,” Troutt said. “So, getting ahead of the curve now, protecting those really key pieces of shoreline now before they become degraded and then investing some resources into restoring those areas, working with landowners to restore those areas as possible. But it’s also going to take some courage by our local elected leaders and state elected officials to do the right things when it comes to regulations.

“I think there has to be a mix of voluntary programs and incentives but also regulatory approaches to protect this stuff,” he continued. “It’s changing quickly and it’s so hard to reverse once you’ve made those changes that we have to have the proper use of all tools, including regulations.”