By CalTrout's partners at the UC Davis Center for Watershed Sciences
As of 2021, California is home to 31 distinct kinds of native salmon, steelhead and trout species, 20 of which are found only in our state. These fish are prized for their economic and cultural significance by local communities, and for their recreational attributes by anglers from around the world.
But these fish face an alarming threat that can't be ignored. If current trends continue, nearly half of these fish will be extinct within the next 50 years.
How do we know this? And perhaps an even better question: what can be done about it?
The answers to both of these questions are rooted in CalTrout's history of turning science into action, made possible by our close relationship with the UC Davis Center for Watershed Sciences. Our partnership has grown over the decades, including the creation of a university endowment by CalTrout benefactors, ensuring this important collaborative science continues into the future.
CalTrout and UC Davis scientists have worked along side each other for many years, their work culminating in 2017 with the seminal report, SOS II: Fish in Hot Water. The only comprehensive review of all native salmonids in California, this peer-reviewed report not only tells us where to focus our efforts, but also how we can support these species through specific restoration and management practices.
By Andrew Rypel, Ph.D., Peter B. Moyle and California Trout Endowed Chair, UC Davis Center for Watershed Sciences
CalTrout, now 50 years old, has grown alongside the fish conservation programs at UC Davis. In the early years, CalTrout was organized as a small group of concerned citizens that had a tenacious focus on improving management of wild trout populations, and also on the nascent (at the time) concept of catch-and-release angling. Initial efforts to examine FERC relicensing agreements on the Eel River exemplified the types of complex challenges CalTrout was willing to take on. During this same time, Dr. Peter B. Moyle relocated to UC Davis, and was beginning to build a dominant career as the world’s expert in the unique and declining native fish fauna of California. Dr. Moyle’s early work culminated with publication of “Inland Fishes of California” – a tour de force on the diversity and emerging challenges for California’s native fish fauna.
Legislative battles fought by CalTrout during the 1980s were successful at fighting back a number of threats to California’s freshwater ecosystems – most notably in the Mono Lake cases. These victories paved the way to protection of four important coldwater fisheries in the Eastern Sierra Nevada, and also began the process of refilling Mono Lake. By this point, CalTrout had developed a strong reputation for science-based fish conservation and its role in developing better policy on state and fish policy. During the 1990s, work and areas of emphasis between CalTrout and UC Davis began to converge more directly. Fish conservation science was in full swing at UC Davis. Dr. Moyle had trained a generation of fisheries professionals that were filling the ranks of state and federal agencies, as well as academic and other positions across the world.
In 1998, Geologist Dr. Jeff Mount teamed with Dr. Moyle and engineer Dr. Jay Lund to establish the Center for Watershed Sciences (CWS) at UC Davis. CWS was formed as a hub for interdisciplinary science on campus and was aimed at providing tangible solutions to long-vexing water problems. It became a non-partisan forum for problems, served as a gathering spot for dialogue, helped connect global and local ideas, and began to serve as a talent pipeline for students engaged in actionable interdisciplinary science. Collaborations between CWS and CallTrout quickly grew and continue today. Some of the best examples include early floodplain work on the Cosumnes River, the “Nigiri Project,” and water temperature and Coho salmon work in Big Spring Creek and the Shasta River. Extensive collaborations between CWS faculty, staff and students with CalTrout continue today.
Sometime around 2012, discussions between CalTrout and UC Davis began around the idea of developing an endowed chair professorship at UC Davis. Similar to the beginnings of CalTrout, the motivation for the position was driven by a group of donors concerned with the conservation and management of coldwater fishes in California. Formed in 2014, the Peter B. Moyle and California Trout Endowed Professorship honored Peter Moyle and the historical and productive working relationship between CalTrout and UC Davis. Furthermore, the chair position ensures that UC Davis will remain a hive for research and teaching activities on native California fishes for generations to come.
In 2017, I was thrilled to be hired as the inaugural chair holder. Work in the Rypel Lab specializes in questions emerging at the science-policy nexus, and many students in the lab work closely with CalTrout staff on their research projects.
By Peter B. Moyle, Ph.D., Distinguished Professor Emeritus, UC Davis Center for Watershed Sciences
California Trout has a long history of using the best available science to support advocacy for protecting salmon and trout populations. Members realized that good angling experiences depended on healthy fish living in healthy waters. Their original motto, after all, was “Keeper of the Streams.”
But California’s fishes were not doing well. Reversing the trend would only be possible through science-based solutions. So, in 2007, CalTrout approached me (a long-time CalTrout member) about finding a way to start conserving fish in a more systematic matter. The result was a 2008 report by myself, Josh Israel, and Sara Purdy called Salmon, Steelhead, and Trout in California: Status of an Emblematic Fauna. The report provided a detailed account of the biology and status of the 31 kinds of salmonid in California, with recommendations for actions. A key part of the report was a repeatable method for numerically rating the status of each species: a survival score. CalTrout then produced a dramatic, colorful version of the report intended for a more general (non-scientific) audience. SOS: California’s Native Fish Crisis was widely distributed to policy makers, politicians, and activist anglers, emphasizing the need for action as backed up by solid, peer-reviewed accounts of each species.
In 2017, CalTrout issued an updated, expanded version of the report by myself, Robert Lusardi, and Patrick Samuel (now CalTrout's Bay Area regional director). The popular version of this report was called SOS II: Fish in Hot Water. This report expanded the previous one, with new and better information. It showed that while there were some bright spots—often actions taken directly by CalTrout—the situation had not improved much in the nine years since the initial report was published.
The updated report emphasized two findings in particular: first was the growing problem of climate change, creating unpleasantly warmer waters for cold water fish. The second was creating a list of actions that could be taken for each species.
Species survival scores from SOS II: Fish in Hot Water
By Rob Lusardi, Ph.D., California Trout - UC Davis Wild and Coldwater Fish Scientist
The State of the Salmonids II report is the only comprehensive review of all native salmonids in California and plays an important role in both capturing recent status trends of each species, but also helps guide recovery and restoration efforts on the ground. The scientific report has been cited numerous times in the scientific literature, often in terms of the current plight of these species, but more generally, the citations appear in scientific manuscripts that aim to recover one or more of California’s native salmonids.
While species accounts from the 2008 version comment on specific actions to help recover each individual species, the 2017 version goes one step further and makes holistic and robust recommendations for the broader species complex. These recovery recommendations are independent of species and geography and drive California Trout’s strategic plan. The recommendations are steeped in science and include six broad based themes across the salmonid landscape, including: protecting and improving current salmonid strongholds, protecting and restoring source waters, restoring productive and diverse habitats, adopting a reconciliation ecology approach as a basis for management, improving habitat connectivity and passage to historical habitats, and, finally, improving the genetic management of salmonids throughout the state.
CalTrout is working to remove this 1950s hatchery dam blocking 9 miles of salmon and steelhead habitat on Cedar Creek, a tributary of the South Fork Eel River.
The SOS recovery recommendations are guiding principles that help inform and prioritize on-the-ground restoration. This can be readily observed in the Mt. Shasta region through a strategic investment in productive and diverse spring-fed rivers that will be key to anadromous recovery, while at the same time protecting resident salmonids from a rapidly changing climate. The same can be said for the North and South Coast, where investments in fish passage to historical habitats are having real and quantifiable benefits and also through an adoption of a reconciliation ecology approach as the basis for management in the Central Valley, where flooded rice fields are being used to mimic natural floodplains to improve the growth and condition of out-migrating salmon.
In short, the State of the Salmonids report not only defines the current status and trends of all salmonids in the state, but uses science to guide restoration and recovery efforts across California’s diverse landscapes.
CalTrout - UC Davis scientists on Central Valley Floodplains
We’ve seen tremendous success over our first 50 years, but our work has only begun. Together, we can protect California's clean, cold water for generations to come.
For our Future. For California. Forever.
Peter Moyle is the Distinguished Professor Emeritus in the Department of Wildlife, Fish and Conservation Biology and Associate Director of the Center for Watershed Sciences, at UC Davis. He is author or co-author of more than 240 publications, including the definitive Inland Fishes of California (2002). He is co-author of the 2017 book, Floodplains: Processes and Management for Ecosystem Services. His research interests include conservation of aquatic species, habitats, and ecosystems, including salmon; ecology of fishes of the San Francisco Estuary; ecology of California stream fishes; impact of introduced aquatic organisms; and use of floodplains by fish.
Robert Lusardi is the California Trout/UC Davis Wild and Coldwater Fish Researcher focused on establishing the basis for long-term science specific to California Trout’s wild and coldwater fish initiatives. His work bridges the widening gap between academic science and applied conservation policy, ensuring that rapidly developing science informs conservation projects throughout California. Dr. Lusardi resides at the UC Davis Center for Watershed Sciences and works closely with Dr. Peter Moyle on numerous projects to help inform California Trout conservation policy. His recent research interests include Coho salmon on the Shasta River, the ecology of volcanic spring-fed rivers, inland trout conservation and management, and policy implications of trap and haul programs for anadromous fishes in California.
Patrick Samuel is the Conservation Program Coordinator for California Trout, a position he has held for almost two years, where he coordinates special research projects for California Trout, including the State of the Salmonids report. Prior to joining CalTrout, he worked with the Fisheries Leadership & Sustainability Forum, a non-profit that supports the eight federal regional fishery management councils around the country. Patrick got his start in fisheries as an undergraduate intern with NOAA Fisheries Protected Resources Division in Sacramento, and in his first field job as a crew member of the California Department of Fish & Wildlife’s Wild and Heritage Trout Program.
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Dams block access to historical spawning and rearing habitats. Downstream, dams alter the timing, frequency, duration, magnitude, and rate of change of flows decreasing habitat quality and survival.
The findings from this study have made it clear – the time to act is now. We can work together to ensure that California will always have resilient populations of wild fish thriving in clean, cold water streams.
Here are some things you can do today:
This factor refers to hard rock mining, from which contaminated tailings, mine effluents, and toxic pollutants may have been dumped or leached into streams, mostly from abandoned mines. Mercury mining, used for processing gold in placer and dredge mining, left a lasting negative impact on wildlife.
Hatcheries and releases of hatchery reared salmonids into the wild can negatively impact wild populations through competition, predation, disease, and loss of fitness and genetic diversity. Hatchery influences are especially apparent to for anadromous species where dams blocked access to spawning habitat and hatcheries were established as mitigation. Inland trout can also be impacted with stocking of hatchery fish for recreation.
All anadromous salmonids depend on estuaries for rearing during a portion of their lives. Most estuaries in the state are highly altered from human activities, especially diking, draining, and sandbar removal between the estuary and ocean. Land-uses surrounding estuaries often involve extensive wetland reclamation, greatly reducing ecological function and habitat complexity.
Harvest relates to legally regulated commercial, tribal, and recreational fisheries, as well as illegal harvest (poaching). Over-harvest can have substantial impacts on fish populations, particularly for those with already limited abundance or distributions, those which are isolated or reside in discrete habitats making them easy to catch (e.g. summer steelhead), or those that attain large adult size (e.g., Chinook salmon).
Transportation corridors such as highways confine stream channels and increase sedimentation, pollution, and habitat degradation from storm runoff and altered streamflows. Culverts and other passage or drainage modifications associated with roads often block migration and restrict fish movements, which can fragment populations.
Many heavily logged watersheds once supported the highest species diversity and abundance of fishes, including anadromous salmon and steelhead. Improperly managed logging increases sediment in streams, increases solar input which increases stream temperatures, and degrades riparian cover. Stream habitat is also degraded by the extensive network of unpaved roads that supports timber extraction.
Non-native species (including fishes and other aquatic organisms) are ubiquitous across many of California’s watersheds; their impacts on native species through hybridization, predation, competition, increased disease transmission, and habitat alteration can be severe.
Wildfires are a natural component of California’s landscape. However, fire suppression, coupled with climate change, has made modern fires more frequent, severe and catastrophic. The transition from relatively frequent understory fires to less frequent, but catastrophic, crown fires can have a severe impact on fish habitat and wipe out populations with narrow habitat ranges.
Impacts from agriculture include streams polluted by agricultural return water or farm effluent; reduced flow due to diversions which can affect migratory patterns; and increased silt and pesticides in streams. Marijuana grow operations, legal and illegal, were considered in this metric.
As California’s population grows, rural development increasingly encroaches along or near streams. Resulting impacts include water diversions, groundwater pumping, streambed alteration (to protect houses from flooding, construct road crossings, etc.), and pollution (especially from septic tanks and illegal waste dumping).