By Sierra LeTourneau, SPAWN Salmonid Monitoring Intern

Header photo of a happy SPAWN Nursery-grown lupine at Chicken Ranch Beach in Tomales Bay, California.

In honor of Endangered Species day, which was this month on May 17th, we wanted to highlight the work SPAWN has done to improve populations for some of California’s listed Endangered Species.

SPAWN as a program seeks to support the endangered Central California Coho populations. Through almost 30 years of monitoring, habitat restoration, and litigation. SPAWN has sought to improve the Coho population in the Lagunitas Creek Watershed.

Recently, SPAWN has been contributing to the restoration of Chicken Ranch Beach as part of the Tomales Bay Foundation’s initiative to improve the water quality and habitat at CRB. This project seeks to provide habitat for a few more of California’s listed endangered species. This includes the tidewater goby, California red-legged frog and the western pond turtle. 

The tidewater goby (Eucyclogobius newberryi), is a small fish that lives in brackish waters, areas that are a confluence of freshwater and saltwater. Tidewater gobies rarely exceed 2 inches in size. Historically they were found in over 150 lagoons and estuaries in California, in 1994 due to massive habitat loss and disruption the tidewater goby was listed as an endangered species. Tidewater gobies prefer submerged and emergent aquatic vegetation, for foraging and juvenile rearing, which is included as part of the CRB restoration efforts. 

The California red-legged frog (Rana draytonii) , another well-known endangered species, was also in mind during the planning for the restoration at CRB. Since 1996, The California red-legged frog (CRLF) has been listed as an endangered species. Much like the Tidewater goby, their status is a reflection of depleted habitat and resources as a result of anthropogenic development. CRLF needs habitat for aquatic breeding, aquatic non-breeding habitat for juvenile and adult dispersal and predator avoidance, and upland riparian habitat adjacent to the aforementioned aquatic habitat. CRLF are more sensitive to changes in salinity than tidewater gobies, planning for both of their needs overlaps significantly in the CRB restoration plan.

Lastly, the western pond turtle (Actinemys marmorata) is not currently listed as an endangered species in the state of California but rather a species of special concern. They were also included in the CRB planning efforts. Their populations have dwindled as a result of disease and habitat destruction, and predator introduction. Elements in the CRB planning for the western pond turtle habitat include submerged longs, large rocks, and muddy banks. 

As of May 2026, we have been working on weeding at the site and implementing irrigation to keep the plants watered as we get closer to the start of summer. Volunteer days at Chicken Ranch Beach remain on alternating Wednesdays and Saturdays, please check the schedule and stop on by to help out!

By Sierra LeTourneau and John Weber

Coho salmon inherently prefer to travel all the way up the watershed into tributaries, small head water streams to spawn. This can be difficult for the species as tributaries are farther upstream than other salmonid spawning sites. The Coho native to Lagunitas watershed, travel through Lagunitas creek up the inkwells that stem into San Geronimo Creek and into the various tributaries that we monitor, most of which require passing through culverts under the roadways (the inkwells are a short cascade segment – like a stair step of pools where San Geronimo creek joins into Lagunitas creek, shown in map below). These culverts were created decades ago with little regard for spawning salmon, mostly having some form of a lip creating an obstacle both to spawning adults and emigrating smolts. These creeks are pictured in our sketched map of San Geronimo creek and its tributaries. 

Sketched Map of San Geronimo Creek and its Tributaries

The broken portion of the maps indicate seasonality of the tributaries.

Coho, though a more charismatic species, are on the endangered species list. Most concern for their endangered status originates from the degradation of their freshwater habitat. Marin is home to the largest population of historic Central California Coho, SPAWN is one of the organizations that monitors this region’s spawning activity, in collaboration with Marin Water and the National Park Service.

From its inception, SPAWN has worked to improve habitat through various restoration projects to encourage the increase in spawning activity and subsequently the Coho salmon population. Originally neglected, the San Geronimo tributaries have only been surveyed since 1997, since SPAWN has started monitoring them. Below is a graph that shows the amount of redds in San Geronimo creek and the tributaries, additionally included is a graph representing the percentage of redds observed in the tributaries specifically. This historically sits around 40% of the total redds counted. From our current findings this season we have identified 28 Coho redds throughout our tributary system. The numbers from the San Geronimo Creek have not yet been independently reported.

Historical Coho Spawning Data

The Coho life cycle in total is about 3 years; they spend around 9 to 12 months where they are spawned in the freshwater ecosystem, then go out to the ocean for 18 months to utilize the food and nutrients of the ocean and grow into mature adults, before they return to their nesting grounds to spawn and shortly after die. The life cycle of anadromous fish allows for nutrients that are carried out of the freshwater ecosystem and  into the ocean to be replenished once the previously ocean bound fish return and die. Which is vital for the entirety of the ecosystem supported by the creek. 

Aside from the expected adult female and adult male Coho, there is a third category of fish that returns for the spawning season, called a “jack” A jack is a juvenile male, every spawning season some of the salmon come back prematurely, mostly males, though jills have been sighted before. Their reason for their premature return is not always clear and can include factors such as genetic predisposition or faster growth due to a successful season at sea. Below we have charts indicating our Coho sightings broken down into individual creeks. You’ll notice from our numbers we did see a couple jacks this season!

As the season matures and spawning activity reduces, we plan to further analyze our results and historical data with hopes of learning more about spawning trends and factors that influence a successful spawning season in our tributaries. We are interested in further investigating the impact culverts place on spawning and successful smolt emigration and looking into rain events, and the impact of their presence or absence. Ideally we can use our findings to improve our restoration efforts moving forward. 

Pictures of Salmonid Monitoring featuring volunteer, John Weber (left) and (right) Montezuma Creek; Jack pictured above the female. Decay of back fin from digging identifies the larger Coho as female.

The fish are running! Salmon have returned to the creeks of the Lagunitas watershed, and now is the time to see this remarkable migration firsthand.

Turtle Island Restoration Network’s SPAWN program is offering expert-led creek walks where you can observe spawning salmon, learn about their natural history, and hear directly from watershed experts about the conservation work protecting these fish and their habitat. These guided walks take place in the Lagunitas Creek watershed, one of California’s most important remaining coho salmon strongholds. You’ll learn why this watershed matters, what salmon are up against, and how conservation efforts are making a difference.

• FREE w/ family memberships (of $50 or more) for up to 5 people.
• $15 per person for non-members
• Dress for cold and wet weather
• Bring binoculars if you have them
• Register soon — maximum 15 people per tour – waiting list after that (events may be cancelled if less than 10 registrants.)
• Email KBouley@tirn.net to reserve your space!
• Large groups please contact for private tours.

Space is limited, and salmon runs are short-lived. Visit our events calendar to see all dates and details: https://seaturtles.org/events/

To register, email kbouley@tirn.net.

When funding shortfalls and staffing cuts caused by the Trump administration threatened to derail a vital habitat restoration project in Muir Woods National Monument earlier this year, SPAWN stepped in to ensure the work could continue. Together with the National Park Service, we completed key improvements to Coho salmon and steelhead trout habitat in Redwood Creek – an effort made possible by a grant from the Woodard & Curran Foundation, Turtle Island Restoration Network supporters like you, and working in collaboration with Symbiotic Restoration.

This year’s project introduced an innovative restoration method known as Post-Assisted Log Structures (PALS)—a first for both the Redwood and Lagunitas watersheds. These hand-built structures use locally collected small- to medium-sized wood, anchored with posts driven into the creek bed to mimic natural log jams. By increasing habitat complexity, PALS provide essential shelter and slow-water refuge for young salmon during their critical 18 months in freshwater before they head to the ocean. Read more about this exciting project and explore photos and videos here.

Read the full piece on NBC Bay Area here!

Rain and spawning salmon go together, and the winter season of 2024-25 had a plethora of both!  Getting to see these fish, some reaching more than 3 feet in length is an amazing and joyful experience!  In Marin, we saw the largest number of endangered coho and threatened chinook salmon in three decades.

I have received calls, photos and video from places where salmon haven’t been seen in the Bay Area.  And everyone I run into the San Geronimo Valley has a story to tell— ‘more fish than ever’ — or haven’t seen them in my backyard creek in 30 years.

While there is a general misconception that more rain means more salmon, there are a number of reasons that help explain what’s going on this winter season.  It is way more complicated than the amount of water, but includes the right amount of water at the right time that really worked in favor of salmon migration this year.

First, many of the salmon seen during and right after our December atmospheric river were chinook or king salmon.  The vast majority of these now begin their lives in hatcheries and do not necessarily return to their natal streams like “wild” salmon do.  And for the past two years, the normal fishing season has been shut down due to low returns of chinook salmon, reducing one of their main predators in the ocean, us.  That and the juvenile fish released from hatcheries must have experienced good environmental ocean conditions allowing for increasing the survival numbers.

The atmospheric river helped the fish bring lots of sustained rain right at the ideal time allowing the fish to maneuver through or around culverts running under roads that often prevent them from migrating to many historic spawning grounds now blocked.  The velocity of water running through many of these undersized culverts is constricted which increases velocity (think putting your thumb at the end of a water hose), and the downstream ends of culverts often erode the stream causing the culverts to be perched high above the creek making passage difficult, if not impossible most of the time.

Federal and State funding for replacing culverts that are migration barriers was massively increased through Biden’s Infrastructure bill, which has helped open up historical spawning grounds to salmon in other locales, but little work has been done locally in the past decade. More is needed to open up more habitat!

The art and science of streamside habitat restoration, also funded by State and federal grants, has also matured over the past two decades, as we have learned from past successes and failures in the young field of restoring functional ecosystems that salmon need to survive and thrive.  The decades of hard work by non-profits and agencies may finally be producing results increasing salmon survival in our local creeks and rivers.

Lastly, better understanding of the ecological benefits of a healthy functioning ecosystem for the survival of salmon and other wildlife, and which also protects our homes and the lives from flooding events exacerbated by climate disruption, increases water filtration into underground aquifers, and filters pollution from our recreational sites, leads to better informed regulations to protect our environments.  But salmon numbers are up throughout Central California with different areas having various amounts of restoration work.  This suggests that as important as restoration is, it cannot completely explain the increased spawning population

While the political will to protect and restore our environment is not always at the forefront of our decision-makers under pressure from developers and corporations, an informed and active citizenry can keep progress moving forward—and increase the chances that we will see even more salmon and wildlife in future years!

Get involved and enjoy our healthier streams and more abundant salmon that brings us joy and makes healthier, happier communities! Join us in Marin County by visiting SPAWN at www.seaturtles.org/spawn.

By Ayano Hayes, Watershed Conservation Manager

As spring gives way to summer, we’re excited to share early insights from the 2025 salmon smolt outmigration season in the Lagunitas Creek watershed. Smolts are young salmon that have reached a key life stage after spending a year and a half in the freshwater streams, they are now preparing for the transition to saltwater life in the ocean. This phase, known as smoltification, involves major physiological changes that allow them to survive in a new and very different environment. Their successful migration downstream is critical to their survival and, ultimately, the health of future salmon runs. 

SPAWN has a monitoring station in San Geronimo creek, the upper tributary to the mainstem Lagunitas Creek. From April to June, the smolt trap was in place, spanning the width of the creek, capturing everything moving downstream. The trap was checked daily in order to safely and successfully process and collect data on this outmigrating class. Outmigration timing remained consistent, total captures peaking throughout April, coinciding with ideal water temperatures but low flow rates. Here’s what we found…

Highlights from the 2025 Season:

This coho salmon cohort originated from the strong 2023/2024 spawning season. However, as juveniles, they endured very wet and stormy few winters, and benefited from favorable streamflow conditions this spring. The total counts for the San Geronimo creek smolt trap produced 1,210 coho smolts with a population estimate of 3,192 ∓635 individuals. The results are an improvement in recent years for the upper tributaries but less than expected for the entire Lagunitas Creek watershed. Marin Water shared preliminary population estimates for the watershed being around 12,000 coho smolts, which is less than 3 years ago but similar to 6 and 9 years ago. The National Park Service, Point Reyes National Seashore, also shared lower than expected counts out of Olema creek, another major tributary to Lagunitas Creek. Expectations were based on the number of nests laid and the number of juveniles observed before the winter and summer preceding migration for this class. Lower than expected counts may be attributed to low winter survival but a more detailed analysis will be available later this year. 

View the graph here showcasing coho salmon smolt population estimates since 2006 for San Geronimo creek: Annual Coho DARR Estimates

The smolt trap season also allows biologists to measure and weigh the smolts since the larger the smolt at the time of outmigration, the higher chance of survival in the estuary and ocean they will have.  Based upon the coho smolts captured in the San Geronimo trap, the average length was 99mm with an average weight of 10g, which is smaller in size but significantly lighter in weight compared to previous years data. Coho smolts averaged around 125mm out of Olema. Data on fish weight and size gives a clue to food availability and with smaller fish coming out the the upper tributaries, restoration goals may need to target food and habitat abundance. 

Another highlight of the season was that chinook salmon were recorded in the San Geronimo smolt trap. This indicates a second year of successful chinook spawning in the San Geronimo creek watershed. Unlike coho salmon who wait 1.5 years before they begin their downstream migration, chinook juveniles will migrate to the estuary 5-7 months after being born. In 2022, 234 chinook juveniles were captured while this year, following a record year of chinook spawning in the watershed,  747 chinook juveniles were in the San Geronimo trap. They ranged from 40mm to 70mm with several over 80mm. With an increase in chinook salmon presence in the watershed, competition for food may have impacted the coho salmon’s feeding potential. 

Threatened steelhead are also found in the San Geronimo smolt trap and this year, steelhead smolt numbers were low but consistent for what is usually captured in the San Geronimo creek smolt trap, around 10 smolts. Steelhead juveniles totaled 595 individuals. The results found from fisheries monitoring within the watershed help inform habitat restoration priorities and give us a real-time look at the health of our salmon populations.

As always, your support helps make this monitoring work possible. Stay tuned for the full season report, and thank you for being part of the effort to protect and restore this critical watershed for the endangered and threatened salmonid species. 

For Immediate Release, May 19, 2025

Contact: Ayano Hayes, Watershed Conservation Manager, ahayes@tirn.net

Habitat Restoration Field Showcase (New Date!): Sediment Load Reduction Project in the Lagunitas Creek Watershed

MARIN COUNTY, CA — On Wednesday, May 28 from 9:00am-1:00pm, join SPAWN and Pacific Watershed Associates (PWA) for an exclusive Field Showcase following the first winter of the Sediment Load Reduction Project in the Lagunitas Creek Watershed. This is your chance to see environmental restoration up close and learn directly from the experts behind it.

We’ll kick things off with a brief presentation introducing the project’s goals, strategies, and results so far. Then, embark on a guided field tour of key restoration sites, including:

• Floodplain restoration at the former Redi-Mix Concrete Plant on Black Mountain Ranch
• Sediment control and road improvements on Zanardi and McIsaac Ranches (GGNRA land)

Explore how impaired dirt roads were decommissioned or upgraded and how stream crossings were redesigned to improve water quality and habitat. This innovative project targets priority areas where sediment threatens the survival of juvenile salmon—a critical concern for the Lagunitas Creek Watershed.

Watershed Conservation Manger, Ayano Hayes explains, “this project highlights how addressing erosion from upland roads can have a profound impact downstream. By reducing sediment delivery into Lagunitas Creek, we’re directly improving habitat conditions and water quality for endangered salmonids during their most sensitive life stages. This tour offers a unique opportunity to visit project sites on protected lands – and see the tangible results of this restoration work up close.”

See the transformation for yourself with dramatic before-and-after views, and gain insight into the design, implementation, and lessons learned from this impactful watershed restoration effort. This project was funded by the United States Environmental Protection Agency under the Federal Nonpoint Source Pollution Control Program (Clean Water Act Section 319) through an agreement with the State Water Resources Control Board.

Don’t miss this opportunity to witness real-world restoration work and connect with others working to protect California’s precious salmon habitat. 20 person attendance cap for the Field Showcase. Inquire and RSVP to Ayano Hayes, ahayes@tirn.net.

For more details on SPAWN’s habitat restoration work, the native plant nursery and how to get involved, please visit https://seaturtles.org/spawn/.

Turtle Island Restoration Network is a global ocean conservation nonprofit with offices in California and Texas, whose mission is to inspire and mobilize people around the world to protect marine biodiversity, the oceans and watersheds that sustain all life on Earth.

For Immediate Release, November 23, 2024

Coho and Chinook Salmon Spawning in Marin County

Recent Atmospheric River Rain-Storm Bring Endangered Salmon Back to Creeks in West Marin

Olema, Calif. (November 23, 2024)

WHAT: Critically endangered Coho salmon are spawning in Marin County now! These large, two-foot-long, beautiful red fish return from the ocean to small creeks to spawn each winter. Once numbering in the thousands, only a couple of hundred now return. This Saturday, Coho were spotted jumping at Inkwell, and both Coho and Chinook salmon were seen spawning at Leo T. Cronin. One of the best runs left in California is right here in the Bay Area in Marin County.

WHO: SPAWN, a project of Turtle Island Restoration Network, can provide opportunities to interview biologists and naturalists, as well as chances to film/photograph fish spawning and leaping through waterfalls.

WHERE: San Geronimo Valley and Olema, CA, in Marin County (approximately 5 miles west of Fairfax, CA)

WHEN: November 2024 through January 2025 (estimated).

WHY: Endangered Coho salmon are on the brink of extinction, yet one of the largest populations left in California occurs within 35 minutes of the Golden Gate Bridge.

The Salmon Protection And Watershed Network (SPAWN) is a program of the global ocean conservation non profit Turtle Island Restoration Network that protects endangered, wild coho salmon and the forests and watersheds they need to survive in West Marin County, California. Learn more at www.seaturtles.org/salmon. 

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