If you’ve ever driven on I-5 north of Olympia, you’ve likely been struck by the unique landscape of the Nisqually River Delta. With Mount Rainier looming in the distance, a huge expanse of marshlands extends on either side of the highway where the fresh water of the river meets the salt water of southern Puget Sound. This is the southern end of the Salish Sea.
The Elwha is now free-flowing through Olympic National Park into the Strait of Juan de Fuca. And it has been quickly returning the sediment that had been held back by two dams for nearly a century.
If you take time to stop, you can explore the Billy Frank Jr. Nisqually National Wildlife Refuge. A boardwalk trail provides easy access to the heart of the estuary, where tides flow in and out, creating critical habitat for all kinds of creatures.
“This is an amazing, productive ecosystem. Probably the most productive ecosystems in the world are these river deltas, where the freshwater meets the sea,” said David Troutt, a salmon biologist and Director of Natural Resources for the Nisqually Tribe. The tribe has been actively restoring the wetlands here since 1995.
Troutt and his staff of researchers monitor the recovery of the estuary, looking at what fish are feeding on and how many pass through. The estuary serves as a kind of nursery for juvenile salmon, which rear here in the marshy sea grasses until they’re strong enough to make their first journey out to sea.
“They’re feeding and growing to reach certain sizes, to increase their survival as they head out to the Pacific Ocean,” Troutt said.
He says the salmon stay from three to six weeks and can double or triple their size in that period of time. They’re also at the stage in their life when they’re changing physiologically, from a freshwater animal into one that survives in salt water.
“That all occurs in the estuary, and you need a transition area for these fish to be able to adapt gradually into that. So the Nisqually Delta and all the work we’ve done give the fish a great opportunity to slowly adapt from fresh water to salt water,” Troutt said.
But right now, a lot of the work Troutt does is focused on steelhead, a unique anadromous trout that can spawn multiple times. It makes the journey through the estuary three to four times.
“And that’s a really important life history trait, to be able to survive and come back and spawn again and again. It’s an evolutionary strategy to maintain a population,” he said.
Troutt says the steelhead and salmon have special importance in the Nisqually culture. A lot of his work has been focused on trying to make sure they’re healthy and their populations are stable.
But it’s been a struggle, in particular with the steelhead. Troutt said there used to be between 6,000 and 8,000 steelhead returning back to the river each year. In the early 1990s, it went down to 500 fish. To this day, the tribe doesn’t fish steelhead.
“So I now have a generation of fisherman, who are fishing on the Nisqually River, who have never caught a steelhead, and that’s very sad. And it's a cultural disconnect, and they feel it,” Troutt said.
Troutt’s career goal is to the steelhead back to the tribe. He says the restoration of the estuary and in-stream habitat has been the key to keeping the fish from going extinct.
Over the past 28 years, protected areas have been added. Now, about 77 percent of the river in permanent stewardship. But it’s not yielding proportional results.
“We’ve got the home built for the steelhead, and they’re doing well in the Nisqually watershed, but once they leave the river it's a different story,” Troutt said.
His scientists use acoustic tags to track the fish after they leave the estuary. Their mortality rates shoot up once they leave the delta, with 90 to 95 percent of the fish dying in the 13 days before they get to the ocean.
“They’re challenged between here and Puget Sound and getting out to the ocean to survive. And we’re noticing that our fish simply aren’t surviving,” he said.
The scientists are homing in on what they think is a primary cause: Marine mammal predation.
In years when transient orcas have been in the area, the survival rates of the steelhead went up as high as 30 percent. So they think the orcas, which prey on seals and other large marine mammals, are helping the steelhead survive, by killing or scaring the animals that eat them.
“We noticed that the seals were spending lots of time in their haul-out areas, and not getting into the water as long as the killer whales were around. So even that, just keeping them away from steelhead, made a difference,” Troutt said.
It’s an example of how the chain of life can start in a tributary and extend through its estuary into the depths of the Salish Sea, which then flows into the ocean.
Troutt’s biggest concern for this web, which the Nisqually Tribe has worked so hard to protect, is the pressures of population growth.
“We’ve got basically the city of Tacoma moving into the Puget Sound region in the next 10 years — that size — and they’re going to get plunked into Puget Sound,” Troutt says.
“And Puget Sound, Salish Sea, is an amazing place, and people want to live down near the water and see the water, and those all have associated impacts.”
Figuring out how to accommodate that growth while still protecting the things people love the most will be the big challenge that this generation and those that follow will face, Troutt said.
“And that may mean thinking about growth in a different way. Maybe we’re going up instead of out, and that's a difficult discussion to have in a lot of our communities,” he said.
Troutt is hopeful for the future because he thinks people care about the salmon and steelhead and the sea, rivers and forests that sustain them.
Once researchers and scientists like him figure out how to communicate better with the broader community and speak to their hearts, Troutt says the Salish Sea and all it encompasses can be preserved and protected.
“If you care about something, then you’re willing to listen and consider the facts,” he said.
“We haven’t yet made that first step very effectively, in a broad sense, across the Salish Sea. And I think there’s hope there because if we work on that, we’ll make a difference.”