Rain may provide relief from wildfires in Los Angeles County, but could spell disaster for the only known population of Southern California steelhead trout in the Santa Monica Mountains.

Destructive Palisades Fire appears to have burned through accessible habitat for endangered trout across state and federal communities topanga creeka coastal creek that flows into the Pacific Ocean. But experts say the secondary effects of fires are the biggest existential threat.

A post-fire storm can sweep large amounts of sediment and charred material from bare hillsides into the water where they live, creating a death trap for creatures that cannot escape. Like a fish.

"One of our biggest concerns is ... losing the last fish," said Kyle Evans, environmental program manager for the California Department of Fish and Wildlife.

The state agency is already considering a potential rescue plan. But even if the fish survive, experts say the increased frequency of wildfires in the region could have lasting negative impacts on aquatic life. Some people believe that the health of fish holds a mirror up to the health of our society.

Vulnerable rainbow trout populations are also threatened by the Eaton Fire in the San Gabriel Mountains north of Los Angeles.

Steelhead trout are Same species as rainbow trout, rainbow trouts, but unlike their freshwater-living cousins, steelhead They spend most of their lives feeding in the ocean and return to the stream where they were born to lay eggs.

Tens of thousands of whitebait return to Southern California streams every year, delighting anglers. They swam through much of the Santa Monica River, which stretches from the Hollywood Hills to Point Mugu in Ventura County.

Historical photos show fishermen at the mouth of the Malibu River and elsewhere pulling up stringers filled with large fish that can grow up to 2 feet in length, said Russell Marlow, senior program manager for the South Coast at the California Trout Conservancy. .

Then starting in the 1940s, dams were built in the area, and "that's when we started to see a dramatic decline in the population," Marlow said.

A 2012 federal recovery plan reported that fewer than 500 adult Southern California steelhead return each year to their natal waters between southern San Luis Obispo County and the U.S.-Mexico border. Today that number is likely much lower.

Last year, the unique Southern California population was added to California's endangered species list.

With the population so depressed, "every fish counts," Marlowe said. He called the well-monitored Topanga Creek population "extremely important." According to wildlife officials, the creek is home to 400 to 500 rainbows, which may venture into the ocean.

Santa Monica's steelheads have endured countless trials. In 2018, the Woolsey Fire burned miles of mountains but not Topanga Creek, a fish refuge.

"Topanga is literally the only place they have left," said Evans, who directs the state wildlife agency's fishery program for the South Coast region. He added that they were not affected by the wildfires and were barely hanging on during the drought.

The Palisades Fire started last week, destroying Los Angeles' West Pacific Palisades neighborhood and raging through Santa Monica.

Once it's safe, crews will trek into the mountains where the trout live and determine if any precautions can be taken, Evans said. That might involve moving the fish to a facility for a few months to let "the first ghastly water come out, and then putting them back in."

If they tried, biologists might put the trout in buckets or coolers and take them to the nearest road, he said. They may then be transferred to a truck equipped with a large water tank, aerator and cooler.

"The main factors causing death and stress in these fish are either low oxygen levels in the water or rapid changes in temperature," he said.

While these fish are a priority, experts acknowledge there will be a lasting impact on the ecosystem.

Lee Kats, a professor of biology at Pepperdine University who has studied animals in Santa Monica for 35 years, said these streams are about to experience huge siltation that will "revolutionize" frogs , a habitat for salamanders and other freshwater creatures. This is a group of animals that are already struggling around the world.

In addition to trout, Santa Monica is home to the endangered western pond turtle and California red-legged frog.

Kats said the impact is compounded by the fact that fires in the region now occur every five to eight years instead of historically every 15 to 20 years.

"As fire frequency increases, streams begin to fill with silt, and there isn't enough time between fires to flush out those streams and restore the habitat to what these animals were used to thousands of years ago," Katz said.

Native plants also don't have enough time to rejuvenate, leading to the emergence of invasive species, Cates said. He said his fellow botanists noticed changes in the vegetation, which in turn affected the animals.

Where the Eaton Fire burned, wildlife officials said they were particularly concerned about fish that inhabit Santa Anita Creek, which flows east of Mount Wilson, and the Arroyo Seco River. of the namesake canyon, while the Arroyo Seco River flows through the Eaton Foothills community. La Canada Flintridge and Altadena.

San Gabriel fish are no strangers to flames. The trout population in the Arroyo Seco River that winds past the Jet Propulsion Laboratory has been nearly wiped out. 2009 station fireaccording to a report last year. then the state biologist Moved into 469 Rainbows Rescued from the San Gabriel River basin, biologists feared it would disappear after flooding 2020 Bobcat Fire.

When the bridge fire last year scorched habitat on the East Fork of the San Gabriel River, 503 rainbow fish were moved to nearby streams, in addition to the Santa Ana spotted dace, Santa Ana sucker and arroyo chub, Evans said. middle. This is a pre-emptive action to prevent mudslides from clogging waterways.

But these rainbow trout - identifiable by the iridescent colors running down their sides - are prevented from entering the ocean and back by man-made barriers. Because they cannot develop into steelhead, they have no state or federal protection.

Carl Trout's Marlow describes the species as one of the best indicators of the overall health of our watershed, which he says is inextricably linked to the resilience of our human communities.

"You can tie the survivability of this fish and its continued presence to how we're doing as a society in Southern California," he said.