By Jennifer Junghans

In California, nearly 4,000 native plant and animal species depend on the state’s freshwater ecosystems. 

Trout, salmon and smelt run the rivers and carry nutrients to and from the oceans. Nutrients feed the invertebrates that fuel the food chain that’s hunted by wading birds and mammals. Amphibians reproduce in fresh water where snakes lay in wait nearby. Beavers build their dams, which create habitat and food sources for fish, which people eat. 

And freshwater flora — plants, trees, shrubs, flowers and grasses — have coevolved alongside the animal communities, and their interwoven relationships help define the very nature and function of freshwater ecosystems.

But California’s freshwater ecosystems are in peril. Nearly half of the state’s freshwater species are vulnerable to extinction, while only 6% are protected under endangered regulations, according to a new report, Climate-Smart Tools to Protect Freshwater Ecosystems, published in May by the Public Policy Institute of California. 

Jacob Katz, lead scientist at California Trout, which works to protect and restore the state’s waters and wild fish, says water infrastructure is part of the problem. 

“Where we are now — where it feels like California’s rivers can no longer support its fish — is a direct result of the way in which our state’s water infrastructure was built at a time when people thought they could control nature,” says Katz. “It’s like we built this pyre and now we’re sleeping in it, and then climate change shows up playing with matches.”

While the state is a world leader in environmental regulations with aggressive initiatives in place to respond to climate change, Ted Sommer, PPIC CalTrout Ecosystem Fellow, retired lead scientist for the Department of Water Resources and the lead author of the new PPIC report, says the state’s efforts are a really good start, but it’s not enough.

“There’s an awful lot of species and habitats out there that don’t necessarily have the protections, so we need to make sure that we go through systematically and make sure individual watersheds are covered and that there’s a portfolio of actions,” says Sommer.

Sommer and his team — who met with state and federal agencies, NGOs, universities, tribes and water districts to develop the report — recommend a comprehensive portfolio of 22 resource management tools that can be used collaboratively and tailored to meet the unique circumstances of individual watersheds at the local level throughout the state.

The report sends an urgent message that time is running out to save freshwater ecosystems, and it calls for a shift away from historical conservation management practices that generally focus on single high-profile species or location-specific critical habitat, to a broader scope that uses the tools to manage the biodiversity of entire freshwater ecosystems. And it does so with the mindset that people can no longer look to historical conditions to establish realistic conservation targets. Sommer explains we can’t preserve what we used to have, but instead people must look to the future, which will be different.

“Part of the rationale is that there’s so much uncertainty with climate change that we need to do some bet hedging,” Sommer says. “We can pick what we think are the best solutions right now, but it’s a moving target with climate change, and so we think using what we’re calling a portfolio approach, using a suite of tools, will give us reasonable coverage to save some of these species and freshwater ecosystems.”

But in order for the tools to be effective, Katz says it depends on how people use them. He explains the tools could be used with the same mindset that interrupted the planet’s natural systems, which led to environmental crisis and collapse — or they can be applied within the larger context of reconciliation ecology that aligns management outcomes with the way nature actually functions.

“It’s not just water flowing across the landscape. It’s water flowing across the landscape that then causes willows to grow on the sides of that river and that interrupts the flow on one side and pushes the river toward the other. So, the patterns are an interaction of life … through the landscape, whether that’s sediment down our rivers that supply our marshes that build our beaches, both of which are the most important buffers against the rising sea,” says Katz. “… All of our life forms are adapted to those patterns and that’s the piece that these tools need to be employed toward.”

The report divides the recommended tools — some of which are currently in practice and others that are innovative, controversial and require extensive research — into three categories: habitat support, species support and contingency actions. 

Habitat support tools include improving water temperature, quality and flow toward more natural patterns; restoration projects that expand ranges, connectivity and habitat diversity; invasive species control using mechanical, chemical, robotic and biological agents, among others. Species support tools include planning for range shifts as the planet warms, transporting species to alternative geographic locations and historical habitat lost to barriers, the use of conservation hatcheries, veterinary treatment of populations and individuals in some cases, hybridization of species, selective breeding and potentially gene editing.

Sommer and his team aren’t advocating to begin experimenting with gene editing on species, but he says it could be worth considering as an extreme option in some cases. For example, consider the strategy to reintroduce extinct species (or those that have been wiped out from a specific region) from frozen embryos into a habitat that is much warmer and vastly different from its original environment. Sommer poses, “If you could use CRISPR to take out just one deleterious gene and that would save them, would you go for that?” 

Sommer notes, “None of this happens in a vacuum when we’re talking about resource actions that include not only the trade-offs across the ecosystem … but also the economic, social and cultural trade-offs that have to be considered.”

PPIC will be publishing a complementary report that addresses the legal, regulatory and cultural factors of implementing these tools.

The last category, contingency plans, are controversial by their very nature, according to  Sommer, because they suggest an acceptance that some species will be lost, which could shift efforts away from the priority of saving species. “But we completely disagree,” says Sommer. 

Some of the report’s recommended tools include tissue archives, genetic libraries, seed banks of embryos and gametes, and planning for novel ecosystems. “This type of information that one would collect is exactly what you need to do effective conservation,” he says.

Collectively, the tools require a significant level of human intervention and one may wonder, can’t nature just survive on its own? Sommer refers to the “myth of non-intervention, that there are all these self-sustaining ecosystems out there. … We have our footprint everywhere. We are exerting management on every ecosystem across the state. Even in wilderness areas we are doing management activities to try to keep them in good condition. This is where we are.”

Sommer speaks about the younger generations he’s worked with across agencies and universities. He says they were overwhelmed with the climate crisis and didn’t know where to start. In response, one of the goals of the report was to inspire people to take action.

“I wanted to come up with some ideas for people to latch onto and think about as projects, as goals that are specific solutions,” Sommer says. He hopes that others will use this report as a blueprint to innovate and test different options, so that when decisions need to be made, they’re informed.

“What we have a chance to do is understand the [natural] patterns and mimic those patterns with our management actions,” says Katz, speaking about the application of the report’s tools. “… Then we really get somewhere, right?”

This story is part of the Solving Sacramento journalism collaborative. Solving Sacramento is supported by funding from the James Irvine Foundation and the James B. McClatchy Foundation. Our partners include California Groundbreakers, Capital Public Radio, Outword, Russian America Media, Sacramento Business Journal, Sacramento News & Review, Sacramento Observer and Univision 19.