Most of California’s salmon and trout swimming to extinction says report
May 16, 2017
• Almost all extinct by 2115 if nothing is done
• “This report should rightly be considered an alarm bell”
California’s native fish species likely to be extinct within the next five decades has nearly tripled, from 5 to 14 species and after five years of historic drought, 81 percent of the remaining 31 species are worse off today than they were a decade ago, according to a new report released Tuesday by fish and watershed advocacy group California Trout and the University of California, Davis, Center for Watershed Sciences.
“The health of our native fish is a reflection of the health of our rivers and streams,” says Curtis Knight, executive director of CalTrout. “Declining fish populations indicate degraded waters, which threaten the health and economic well-being of all Californians.”
If present trends continue, 74 percent of California’s native salmon, steelhead, and trout species are likely to be extinct in 100 years, the researchers predict.
In the coming decades, the Central California Coast coho salmon and the Northern California Coast summer steelhead in particular face a high risk of extinction, the report says.
There are eleven other kinds of native salmon, steelhead, and trout in the region: Chum salmon, California Coast Chinook, Upper Klamath-Trinity Rivers spring Chinook, Upper Klamath-Trinity Rivers fall Chinook, Southern Oregon/Northern California Coast fall Chinook, Southern Oregon/Northern California Coast Coho, pink salmon, Northern California Coast winter steelhead, Klamath Mountain Province winter steelhead, Klamath Mountain Province summer steelhead, and Coastal cutthroat trout.
Of these eleven, five are likely to be extinct in the next 50 years if present trends continue.
“This report should rightly be considered an alarm bell, but it should also be seen as a roadmap for how we can correct course to better support native aquatic species,” says the report’s lead author Peter Moyle, distinguished professor emeritus in the Department of Wildlife, Fish and Conservation Biology and associate director of the UC Davis Center for Watershed Sciences,
“Thanks to ongoing scientific research, we now know what to do – and where – to improve the plight of native fish,” he says.
The report includes an analysis of key threats to the survival of each species, starting with the overarching threat of climate change, which is likely to reduce the availability of cold water habitat that salmon, steelhead, and trout all depend on for survival. It also highlights various other human-induced threats, such as dams, agriculture, estuary alteration, urbanization, and transportation.
In the Central Valley, improving prospects for imperiled fish like the Sacramento winter-run Chinook salmon includes providing opportunities for juveniles to access floodplain-like habitat (on fallow farm fields and other designated floodways), taking steps to prevent returning adults from accidentally straying into agricultural drainage canals, and identifying strategic opportunities to improve conditions for the fish through cooperative approaches like the Central Valley Salmon Partnership.
“We have developed scientifically proven opportunities to improve the prospects of endangered fish species like winter-run Chinook salmon,” says Jacob Katz, CalTrout senior scientist in the Central California region. “The trick is to put our plans into action as quickly as possible so that we return these native species to self-sustaining populations.”
The report notes that improving salmonid status throughout California requires investing in productive habitats that promote growth, survival, and diversity. CalTrout has developed an action plan to return the state’s salmon, steelhead, and trout to resilience to help many of these species thrive.
To reverse the trend toward extinction, the report suggests prioritizing protection and restoration efforts in three general areas:
• Protecting the most productive river ecosystems remaining in California, such as the Smith and Eel Rivers, must be a priority. These strongholds, among others, have the capacity to support diversity and abundance because they retain high quality habitat and are not heavily influenced by hatcheries, supporting the persistence of wild fish.
• Increasing focus on source waters will keep more water in streams and reduce stress on fish during drought, buffering the effects of climate change. Sierra meadow restoration, springs protection and progressive groundwater management all contribute to this effort.
• Restoring function to once productive – but now highly altered – habitats can greatly improve rearing conditions for juvenile fish, especially floodplains, coastal lagoons, estuaries, and spring-fed rivers.
Additionally, the report identifies three science-based strategies to support a return to abundance for California’s native salmonids:
• First, focus on opportunities to mimic natural processes within altered landscapes. For example, CalTrout has demonstrated that off-season farmland can mimic traditional floodplains and support rapid growth of juvenile salmon.
• Second, prioritize improving fish passage to historical spawning and rearing grounds that have been cut off over time.
• Last, pursue strategies that increase genetic diversity of wild fish.
“We know we are not going to turn back the clock to a time before rivers were dammed or otherwise altered for human benefit,” Mr. Knight says. “Using the best available science, we can make landscape-level changes that will allow both people and fish to thrive in California.”