During the 2024\u20132025 spawning season, endangered Central California Coast coho salmon (CCC coho) migrated to Mendocino Coast rivers in numbers few scientists thought they would see in their careers. Monitoring teams estimated that more than\u00a030,000 adult coho returned, double the previous season\u2019s record-breaking return of 15,000 coho. These numbers represent a significant leap from the past decade, where as few as 3,000 fish returned annually.<\/p>\n
Several factors contributed to this surge. Many scientists believe that reconnecting spawning streams to mainstem rivers and other large-scale habitat restoration projects significantly boosted their productivity and abundance. These actions expanded and improved the habitat available for salmon to spawn and grow. Since 2000, NOAA has supported more than 100 restoration projects across the region.<\/p>\n
For biologists and restoration practitioners who have spent decades surveying streams with few or no fish, the new numbers feel profound.<\/p>\n
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\u201cI am overjoyed\u2014everybody\u2019s just ecstatic about how many coho there are,\u201d said NOAA Marine Habitat Resource Specialist Joe Pecharich, who has been supporting restoration projects in the region for 20 years. \u201cWe have conducted intensive sampling since 2009 in these watersheds and many of us never thought we\u2019d see something like this in our lifetime.\u201d<\/p>\n
\u201cIt\u2019s very good news for all of us\u2014communities, tribes, NGOs, NOAA, California Department of Fish and Wildlife, and all our partners,\u201d said Joshua Fuller, NOAA\u2019s Coastal California Branch Supervisor. \u201cRecovering salmon is undeniably challenging, particularly for a species that must successfully navigate both freshwater and marine ecosystems during its lifetime. These numbers are very encouraging and demonstrate that recovery is possible when management, habitat, ocean, and hydrologic conditions are aligned.”<\/p>\n
\u201cThe monitoring data reflect more than just increased adult returns,\u201d said Nadia Brunner, supervisory fisheries biologist with the Pacific States Marine Fisheries Commission. \u201cThey speak to years of monitoring, management, and restoration work along the Mendocino Coast.\u201d<\/p>\n
Monitoring Central California Coast Coho Salmon\u00a0<\/p>\n
Central California Coast coho salmon, a\u00a0NOAA Species in the Spotlight<\/a>, are\u00a0the most endangered subset of the coho salmon species.\u00a0The rivers of the Mendocino Coast are part of their range between Santa Cruz in the south and\u00a0Punta Gorda in Northern California. While other areas have seen increases in CCC coho salmon,\u00a0the Mendocino Coast returns are the most dramatic.\u00a0<\/p>\n To estimate the number of returns on the Mendocino Coast, monitoring teams conduct surveys across roughly 500 miles of habitat. The teams are led by the California Department of Fish and Wildlife<\/a>,\u00a0with funding from NOAA Fisheries. Staff from the Pacific Marine Fisheries Commission, Mendocino Redwood Company, and Redwood Timber Company participate in the effort.<\/p>\n Teams visit randomly selected stream sections, known as \u201creaches,\u201d every 2 weeks during spawning season. They count adult fish and redds\u2014gravel nests built by spawning females. At life-cycle monitoring stations crews track\u00a0 juvenile fish traveling downstream and adult fish traveling upstream. They use this information and other data to estimate watershed-wide populations.<\/p>\n Pacific States Marine Fisheries Commission Technician Cami Boesch\u00a0observes adult coho in a stream.\u00a0 Almost 100 coho redds were counted on this reach during the 2024-2025 spawning season.\u00a0Credit: Emily Lang\/Redwood\u00a0Timber Company<\/p>\n What 30,000 Fish Looks Like<\/p>\n Members of the monitoring teams reported that counting fish during the 2024\u20132025 migration was exhausting but\u00a0exhilarating.\u00a0<\/p>\n David Ulrich, a senior scientist at Mendocino Redwood Company, said that in previous years, his team typically surveyed two stream reaches per day on the North Fork Navarro River. Last year, they barely covered half a reach on some days.<\/p>\n \u201cIn the past, we\u2019d have days where we wouldn\u2019t see any fish,\u201d Ulrich said. \u201cLast year we were seeing 50 to 100 fish a day during the height of the spawning season.\u201d<\/p>\n Other team members nearly tripped over salmon while crossing streams.<\/p>\n While surveying the Upper Noyo watershed, Elise Allen, a fisheries biologist with the Pacific States Marine Fisheries Commission, tried to step around a group of about a dozen adult coho.<\/p>\n \u201cI took one step and I think I almost had a heart attack,\u201d Allen said. \u201cA 70-centimeter male coho came out from under my foot and swam between my legs.\u201d<\/p>\n In the tiny tributaries of Pudding Creek, Emily Lang of the Redwood Timber Company found salmon using every available inch of habitat.<\/p>\n \u201cIn a channel about a foot-and-a-half wide, I saw this big, beautiful female on a redd,\u201d Lang said. \u201cI remember thinking that if she tried to turn sideways, it would have been impossible because the channel was so narrow.\u201d<\/p>\n Coho were also observed in the Gualala River watershed for the first time in roughly two decades. Credit: Adobe Stock<\/p>\n Fish Return to Streams for First Time in Decades<\/p>\n Coho also appeared in watersheds where they had not been seen in years. For example, coho were documented in Usal Creek for the first time since 2014.<\/p>\n \u201cWe hadn\u2019t seen coho in that watershed in more than a decade,\u201d Pecharich said. \u201cTrout Unlimited<\/a> has done extensive restoration there, so coho had access to more spawning areas.\u201d<\/p>\n Coho were also observed in the Gualala River watershed for the first time in roughly two decades.<\/p>\n \u201cFinding them in places where they have not been was really exciting,\u201d said Sarah Gallagher, senior environmental scientist with the California Department of Fish and Wildlife. \u201cI got to actually go out and see them in person and snorkel with them.\u201d<\/p>\n Building an engineered log jam on the Ten Mile River. Credit: The Nature Conservancy<\/p>\n Investment in Restoration Pays Off<\/p>\n Scientists believe decades of habitat restoration are beginning to pay off.<\/p>\n \u201cIn combination with improved fisheries management, the Mendocino Coast shows the value of restoration and watershed health,\u201d Fuller said. \u201cWhen good ocean conditions and good hydrology align, restored habitat allows fish to take full advantage of those conditions.\u201d<\/p>\n Over the past two decades, NOAA Fisheries’\u00a0Pacific Coastal Salmon Recovery Fund<\/a>\u00a0and the\u00a0Office of Habitat Conservation<\/a> have invested heavily in rebuilding habitat across Mendocino Coast watersheds.\u00a0<\/p>\n By replacing barriers to fish passage\u2014such as undersized road culverts\u2014with fish-friendly designs, restoration partners have reopened access to spawning and rearing habitat.<\/p>\n \u201cWe don\u2019t want to write off an area just because we haven\u2019t seen coho there,\u201d Gallagher said. \u201cWhen we increase connectivity in the upper and lower reaches, salmon move in and use that space.\u201d<\/p>\n NOAA\u2019s Office of Habitat Conservation currently funds Trout Unlimited to remove barriers in the Navarro, Big, Garcia, and Noyo River watersheds.<\/p>\n Trout Unlimited\u2019s\u00a0Anna Halligan,\u00a0Director of the North Coast Coho Project,\u00a0and\u00a0Karen Jamogochian,\u00a0\u00a0Project Manager,\u00a0looking for spawning coho. Credit:\u00a0Christie Hemm Klok\/Trout Unlimited.<\/p>\n In 2024, Trout Unlimited remediated a barrier in Neefus Gulch, a small tributary of the North Fork Navarro River. The project restored 1,600 feet of stream channel and reopened upstream spawning habitat. Trout Unlimited also removed a barrier on Neefus Gulch in 2021.<\/p>\n \u201cWe visited the site after construction, and there were so many juvenile coho above the former dam,\u201d Pecharich said. \u201cEvery pool had a ton of coho in it. It was really exciting.\u201d<\/p>\n \u201cThis January, Trout Unlimited fisheries biologists conducted spawner surveys in Neefus Gulch and observed 10 coho salmon redds and two steelhead trout redds,\u201d said Anna Halligan,\u00a0director of the North Coast Coho Project for Trout Unlimited. \u201cOf these, eight redds were observed in the newly restored habitat above the former barriers. Salmon have not had the ability to spawn in this area for more than 70 years.\u201d<\/p>\n This year, the organization will reconnect streams at Duffy Gulch in the Noyo watershed and at Soda Creek and Meyer Gulch in the Navarro watershed.<\/p>\n Other projects restore natural stream processes to heavily altered waterways. When channels are straightened and simplified, heavy winter flows can wash salmon eggs and juveniles downstream. Reconnecting floodplains, excavating side channels, and installing engineered log jams create slower water refuges for both adult and juvenile salmon.<\/p>\n Floodplain restoration on the Ten Mile River. Credit: The Nature Conservancy<\/p>\n