Elise Allen is likely to remember this particular moment. During the spawning survey last winter, she reached down to steady herself while wading through the Upper Noyo watershed. She took one cautious step before feeling a tremendous surge from under her boot. A male coho measuring 70 centimeters leaped between her legs and vanished upstream. “I think I almost had a heart attack,” she subsequently admitted. Now it’s a humorous tale. However, it also speaks to the reality of what’s occurring in the rivers along California’s Mendocino Coast: fish are returning in numbers that seem almost unbelievable.
Monitoring teams estimated that over 30,000 adult Central California Coast coho salmon returned to Mendocino Coast rivers during the 2024–2025 spawning season. That is about ten times what biologists were seeing just ten years ago, when annual returns occasionally barely cracked 3,000. It is also double the previous season’s record of 15,000, which was unprecedented in and of itself. These numbers have a significance for an endangered species that is difficult to articulate in terms of science alone.
Something that stuck was said by NOAA habitat specialist Joe Pecharich, who has worked these watersheds for twenty years. It’s important to remember the statement, “Many of us never thought we’d see something like this in our lifetime.” These are the people who crouched next to streams for years, counting virtually nothing, filling out low-number survey forms, and silently questioning whether any of it was effective. It seems that the answer is yes, but a closer examination is necessary to determine precisely why.
Ecologists are still figuring out how a number of factors came together. Over 100 restoration projects along the Mendocino Coast have been funded by NOAA since 2000. These projects include rebuilding floodplains, reconnecting tributaries that had been blocked for decades, and removing obstacles to spawning migration. Within days of the project’s completion, juvenile coho were seen utilizing newly built floodplain habitat on the Ten Mile River. This incredibly quick colonization suggests the fish were prepared and just needed a place to live. Marine survival rates, on the other hand, increased to about 8% from the usual 2% or less. Juveniles were also able to make it to the ocean thanks to favorable downstream flows in 2023 and timely fall rains in 2021.
Monitoring this surge from the ground was a surreal and exhausting experience. According to David Ulrich, a senior scientist at Mendocino Redwood Company, his group used to survey the North Fork Navarro River’s two stream reaches every day. They were only able to complete half a reach last season because there were just too many fish to accurately count. Days that had previously yielded no sightings suddenly produced 50–100 coho. While working a small tributary of Pudding Creek, Emily Lang discovered a large spawning female stuck in a channel that was only a foot and a half wide. “If she tried to turn sideways,” Lang replied, “it would have been impossible.” The image of a fish demanding to survive in whatever space it can find has an almost poignant quality.
Whether these consecutive record seasons indicate a true long-term population recovery or a window of opportunity that may close once more is still up for debate. Coho are still in danger. The sea is getting warmer. Upstream forest management decisions are still very important. However, scientists and restoration workers believe that something structural has changed, that the decades of unglamorous work to remove old culverts and reconnect streams is now manifesting in the data in ways that are hard to ignore.
It’s difficult not to think that this story merits more attention than it usually receives as it develops. A stock surge or a technological advancement make more headlines than a salmon recovery. However, the return of 30,000 endangered fish to rivers where scientists had previously counted none is a rarer and possibly more instructive occurrence than most people are aware.
