L.A. Wildfires Torched One of SoCal’s Last Remaining Steelhead Streams

The Palisades Fire that has been burning for a week in Los Angeles County is only 14 percent contained as of Tuesday, and high winds in the forecast could make matters worse. Officials are already expecting the blaze to rank among the costliest wildfires in U.S. history. And while human health and safety remain the top concerns, state fisheries managers are also warning that the fire could devastate the last known steelhead run in the Santa Monica mountains.

Topanga Creek, which flows into the Pacific Ocean between Malibu and Los Angeles, contains the only remaining spawning habitat for steelhead trout in the Southern California mountain range. The small coastal creek has also been completely scorched over the last week, according to the Los Angles Times. 

While the streams of the Santa Monicas were historically rich in Pacific salmon and steelhead, a host of dams built during the 20th century cut off access to most of these river systems. Topanga is now the only creek in the area where rainbow trout can freely swim to the ocean and back. As such, it’s one of the last strongholds for Southern California steelhead trout, a unique and increasingly rare subspecies of steelhead that was listed as endangered in 2024.   

“One of our biggest concerns … is losing that last population of fish,” California Department of Fish and Wildlife environmental scientist supervisor Kyle Evans told the Times, referring to the steelhead trout that inhabit Topanga Creek.

It’s not necessarily the flames but their aftermath that has fisheries experts concerned, as the charred river canyon will now be extra-prone to landslides. One heavy rain could easily push all that dirt, debris, and charred silt into Topanga Creek. The resulting debris flow would then suffocate nearly every fish in its path. 

This exact scenario has played out in recent years on other Western trout streams, including Colorado’s Cache la Poudre River, where fisheries managers recorded an 80 percent decline in trout populations in the aftermath of the 2020 Cameron Peak Fire. During a survey that was conducted downstream of a hard-hit area a little more than one year after the burn, biologists found a nearly 20-mile stretch of the Poudre that was devoid of trout.

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Due to these very real concerns, Evans said CDFW is already looking at a potential rescue plan, where biologists would hike into Topanga Creek to pull the trout out and then transport them with coolers and trucks to a holding facility. Theoretically, these fish would be returned to the creek after the first big rains pass through and flush most of the silt and charred debris out of the system.

CDFW did not immediately respond to a request for comment about the proposed steelhead rescue. The Los Angeles Times, however, reports that similar rescue plans are being considered for trout streams in the nearby San Gabriel Mountains, where the Eaton Fire is burning.