Fires Restore Wetlands for Desert Fish
By Sam Schipani
It may seem strange to burn the area around the wetland as a habitat restoration technique, and even more oxymoronic to do so in order to save an aquatic creature in the desert. But for a nearly extinct species of fish in the arid Owens Valley, a prescribed burn is exactly what the doctor ordered.
After years of planning, the Eastern Sierra Land Trust, the California Department of Fish and Wildlife, and Cal Fire executed a prescribed burn this past December in order to create a sustainable habitat for the Owens speckled dace, a small fish that is listed as "threatened" under the Endangered Species Act.
Fish in the desert might sound impossible, but there are several species of desert fish in California. During geographically transformative events that occurred thousand of years ago, these fish found their way to tiny pools and streams that punctuate the dry landscapes during wet periods. As landscapes changed over time, the desert fish have adapted into unique species specialized for their environs. According to Peter Moyle, a biologist at University of California, Davis, genomic testing suggests that the Owen speckled dace's prehistoric ancestors came from around the Mono Lake basin, where volcanic activity blew out the waters and dropped the common ancestor of the Owens speckled dace and other dace species into surrounding areas.
"These fish have been going their own way for a very long time and adapted to very difficult conditions," Moyle says. "If we can restore the speckled dace, you'll have brought back a significant part of the fish fauna in that region. It just belongs there."
Over the past 80 years, the Owens speckled dace has been in steep decline due to water mismanagement, pressures from agriculture, and encroachment by non-native species. Streams and seasonal ponds in the Owens Valley are expected to decline further with climate change-related temperature increases and less snowpack, and what has not evaporated will continue to be diverted for agricultural use. Thirsty cattle, a linchpin of the valley's ranching history, are especially hard on area streams. The little water that does remain is often overrun with invasive plants and non-native fish species. According to Moyle, in the 1920s and 30s, any body of water without catchable fish was considered barren. Fish and Wildlife agencies felt it incumbent to remedy the "problem" by relocating catchable fish to these areas, where they are now incredibly difficult to eradicate. The Owens speckled dace is outcompeted and eaten by species like the Sacramento perch, which can grow over five times as large and makes a quick snack of the little dace.
"[The Owens speckled dace] is a native fish, and it's about to be extinct," says Kay Ogden, executive director of the Eastern Sierra Land Trust. "They're desperate for a place to live right now."
In order to save the desperate dace, the Eastern Sierra Land Trust started seeking suitable locations to reintroduce the species. With the help of U.S. Fish and Wildlife Service scientists, the group found the perfect candidate: the Benton Hot Springs Ranch. The spring-fed ponds on the property once contained the Owens speckled dace; with a little help to raise the water level and remove the non-native plants and fish, they could again. The ponds were located on private property owned by fourth-generation rancher Bill Bramlette. Luckily, Bramlette was happy to join the dace restoration efforts. The ranch has been in his family for four generations, and Bramlette is invested in continuing a legacy of responsible habitat management. In 2008, Bramlette signed a conservation easement with the Eastern Sierra Land Trust and agreed to preserve the habitats and prohibit future development in the area.
"I saw an opportunity to do meaningful conservation by working with partners who had access to resources and experts," Bramlette said in an Eastern Sierra Land Trust press release.
With Bramlette on board, the Eastern Sierra Land Trust's staff and volunteers began meticulously removing the invasive hardstem bulrush and cattails choking out the fish habitat in the water. They spent years trying to remove the plants by hand, but the aquatic plants were too aggressive and fast-growing. The only option was to take the plants down in a literal blaze of glory. In 2013, Cal Fire joined the cause to help organize and execute a prescribed burn at the Benton Hot Springs Ranch.
According to Henry Herrera, a unit forester for Cal Fire who worked on the project, properly planning a prescribed burn is a lengthy process, but "the benefits outweigh all the work that goes into it." Besides going through a standard environmental review, the local air quality board must determine whether the wind conditions will impair air quality or cause the flames to stray beyond the prescribed area. Cal Fire also conducts various fire behavior calculations to determine what the ideal environment would be to keep the fire under control. The agency had to check the moisture of the targeted vegetation—too little and it would burn too hot, too much and it wouldn't burn at all. To avoid disturbing nesting birds, most burns can only take place between November and January. Plus, everyone—the Cal Fire crew, the Eastern Sierra Land Trust staff, and Bramlette himself—had to be available. With all the variables at play, it took three years for the stars to align.
"We came really close two years ago and a snow storm came in," says Eastern Sierra Land Trust executive director Ogden. "I cannot even tell you how frustrating that was. But we take fire seriously"
Finally, the Goldilocks conditions emerged. The crews removed heavy fuels like logs, snags, and brush piles away from the site and then started the burn, systematically lighting the perimeter in accordance with the wind. The scene looked apocalyptic as the fire lapped up the brushy plants, but thanks to the careful planning, it went off without a hitch. When the fires subsided, the ponds emerged from clearer and more open to the new possibilities that lie ahead.
Hopefully the Owens speckled dace will have its own phoenix moment soon, but the burn was only the first step in the process to restore the habitat. Next, the water level in the ponds will be raised to drown out any remaining burned and cut plants (all of the plants must be removed—even one aggressive and fast-growing bulrush would start taking over the habitat again). Then, the California Department of Fish and Wildlife will remove and relocate the Benton Pond's non-native aquatic residents. Once the vegetation and non-native predators have been removed from the ponds, the Owens speckled dace will be brought back to its historic home.
The coalition that is working to restore these fish relishes the little victories. According to Ogden, a greater expanse the pond's water surface is already more visible, and birds like ducks, grebes, and herons have returned to the wetland habitats. The Eastern Sierra Land Trust has partnered with Bramlette to host events at the ponds, giving the community the opportunity to view birds and other wildlife in the habitat until the fish arrive.
"It's really fun to see," Ogden says. "Any time that humans can step in and try to collaborate and help save a species, I think it is incumbent upon us to try and do that."