The Importance of Keystone Species in The Tuolumne Watershed
Keystone species keep habitats in balance and remind us that we are a part of a deeply interconnected web of life. A keystone species is defined as a plant or animal that other species in an ecosystem largely depend on. So much so, that if the keystone species were eliminated, the ecosystem would change drastically and potentially collapse.
We have our very own keystone species in the Tuolumne Watershed that needs your help – the threatened Chinook salmon.
The Chinook salmon is considered one of the most important keystone species on the West coast. Before dams were constructed to divert water to farms and urban areas, salmon transported millions of pounds of nutrients from the ocean to upland habitats, where they fueled the food web and fertilized forests, meadows, and valleys. The Central Valley’s rich soils, and subsequent agricultural boom, were made possible by this transfer of nutrients by salmon. Without these nutrients, the entire ecosystem becomes unbalanced and susceptible to collapse
Historically, well over 100,000 salmon spawned in the Tuolumne. After last year's count of only 1,000 salmon, we are fighting for science-based solutions that will give this keystone species a chance to flourish again.
Salmon populations are on the decline, largely due to the lack of freshwater inflow. The salinity balance of the Bay-Delta has been altered to such a degree that it has impacted the entire food web – from bacteria and algae communities, to top predators, such as large birds, bears, and orcas, the Tuolumne’s Chinook Salmon influence survival of countless species in these fragile ecosystems. By altering our freshwater ecosystems so dramatically, humans have created conditions that favor non-native species that evolved in slow-moving, warm water—such as bass that feed on baby salmon—over native species.
In an average year, 80% of the water from the Tuolumne River is diverted for human uses. This isn’t fish vs people, this is fish for people. We won’t survive if they don’t survive.
We are advocating for higher unimpaired flows in the lower Tuolumne and San Joaquin Rivers through the Bay Delta Plan, which would better protect salmon as they make their way to and from the Tuolumne River and the San Francisco Bay.
Phase 1 of the Bay Delta Plan was approved by the State Water Board in 2018, yet little action toward implementation has happened since. Instead, the water agencies have proposed an alternative to the Bay Delta Plan, called a Voluntary Agreement, which would leave very little additional water in our rivers, and would fail to restore the Bay-Delta ecosystem. For years, the Modesto and Turlock Irrigation Districts and the San Francisco Public Utilities Commission have been telling the world they can produce more fish with less water. Well, it turns out their science doesn’t hold water. The National Marine Fisheries Service released a peer review of the fish models upon which their claims are based, and found a number of serious flaws. This undermines the credibility of the proposed Voluntary Agreement, which is one more reason to encourage the implementation of the Bay Delta Plan.
We urge you to take a critical look at the importance of supporting science-based solutions that prioritize protecting keystone species and thus the ecosystem at large. Restoration of river habitat only works when water is added to the landscape. Join us as we urge the State to “Just Add Water!” today.
Click here to learn more about the Bay-Delta Plan.
