Post-wildfire conditions result in poor recovery for fish

By Associated Press
Published: Saturday, March 11, 2023 - 9:35am

Fishing in rivers and streams that cross through a national monument in northern New Mexico is off limits now as wildlife managers look for ways make the area more habitable following a catastrophic fire and years of subsequent flooding.

Managers at Bandelier National Monument issued a temporary fishing closure order Friday, saying Rio Grande cutthroat trout and other species reintroduced following the 2011 blaze aren’t recovering as expected.

Water testing has shown a decline in the insect larva that the fish feed on, and the water temperature also is warmer because of the lack of shade in the burn areas.

“Simply put, there is no food for the fish,” Bandelier Superintendent Patrick Suddath said in a statement. “Even catching and releasing them appears to be causing undue stress.”

Biologists are considering alternative strategies for restoring the riparian habitat so the fish will have better chance of survival. Continued monitoring of the trout population will help to inform any park management decisions, officials said.

The Las Conchas fire — then the largest in New Mexico history — burned so hot in some spots that it turned entire hillsides to ash, leaving behind only charred skeletons of what had been towering ponderosa pine trees.

The flames raced across more than 244 square miles of the Jemez Mountains during the summer of 2011. The fire destroyed several dozen homes, threatened Los Alamos National Laboratory, burned through cultural sites and threatened an important water source for Santa Clara Pueblo.

Downstream communities are still dealing with the lingering effects of the fire.

In 2011 and again in 2013, post-fire floods ravaged Bandelier and wiped out the native fish population. The National Park Service teamed up with the New Mexico Department of Game and Fish to return the Rio Grande cutthroat trout — the only cutthroat trout native to the state — to the area.

Last fall, efforts began to reintroduce the Rio Grande chub and sucker as well.

Data is limited on those species since the work began recently, but officials say the trout appear to be struggling.

The Colorado River below Glen Canyon Dam
U.S. Bureau of Reclamation
The Colorado River below Glen Canyon Dam.

Similar problems have cropped up in other parts of the West, either because of wildfires and flooding or dwindling water supplies and warming temperatures amid climate change.

Those rare species found mostly in small, high-elevation streams — like the Rio Grande cutthroat and Gila trout in southern New Mexico — have been particularly vulnerable.

On the Colorado River, federal managers have a legal obligation to maintain native fish populations under the Endangered Species Act. They have experimented with changing the flow of water from Glen Canyon Dam near the Arizona-Utah border to boost the number of aquatic insects for the fish to eat.

In another stretch of northern New Mexico, crews had to rescue fish from what became the largest fire in the state's recorded history in 2022 when government-sparked prescribed burn operations went awry. They stunned and netted as many cutthroat as possible so they could be trucked south and stored until they could be returned to the wild.

Gila trout also have been rescued over the years as fires have threatened their habitat near the Arizona-New Mexico border.

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