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Experimenting With Mushrooms To Try And Heal Toxic Burn Scars In Santa Cruz

Michelle Loxton.
Fungi have been used for decades to absorb toxins from the environment. Now, a local group is experimenting with mushrooms to specifically heal toxic burn scars left behind after wildfire.

When a massive wildfire tore through the Santa Cruz mountains last year, it destroyed close to 1,500 structures. When a structure is destroyed by fire, toxic materials can leak into the environment. Cleaning up these spills often involves scraping the earth and dumping it somewhere else. But a local group is trying a different approach. They’re experimenting with fungi, which they say has an incredible ability to remove and even heal toxic burn scars.

Maya Elson stands on a property perched on a steep slope overlooking a creek deep in the Santa Cruz mountains. It’s hard to imagine but someone’s home used to stand here. 

“Right after the fire, we came here and everything was gray. You could hardly see anything green. And there were just piles of rubble and ash,” Elson said. 

Elson is the executive director of CoRenewal, a nonprofit that uses science to tackle environmental issues. This heartbreaking scene inspired the team to get to work. 

“You could see aluminum that had been liquefied and had dripped down the hillside,” Elson said.

Elson was very concerned these toxins could make it into the creek and spread throughout local ecosystems and affect  fish, animals and people. That’s where the mushrooms come in — they decided to try something called mycoremediation. Myco meaning ‘fungus’, and remediation meaning ‘returning to what it once was.’ 

“We introduced Pleurotus ostreatus, the oyster mushroom, which has been shown to be able to hyper accumulate metals and, you know, plastic-y stuff, essentially to see if we can use them in this situation to remediate these toxins and trap these toxins,” said Elson.

Credit Michelle Loxton.
Maya Elson checks one of the waddles to see if mushrooms have sprouted. The waddles act like a human sieve — filtering out toxins as water moves through them.


CoRenewal’s Volunteer Mycologist Erica Schroeder demonstrated the process. 

With a spade they dug a shallow ditch horizontally along the slope. Then, they placed a long waddle in that ditch. A waddle is a tube filled with compacted straw. Finally, they sprinkled the waddle with mushroom fungus or spawn.

The CoRenewal team prepares to sprinkle mushroom spawn, donated by a local grower in Moss Landing, along the waddles.


“The oyster fungi will then start to eat and consume the straw and move along the waddle, creating a filtration device,” said Schroeder.

Essentially they’re making a living sieve. And that living sieve will filter water that moves down the slope and take out the toxins.

Credit Michelle Loxton.
Mycologist Erica Schroeder digs one of the ditches they will use for the placement of the waddles.


To monitor just how effective this process is, the team collected samples above and below the waddles at the start of the experiment and will do the same at the end, a year or two later, to check whether the mushrooms decreased the amount of toxins at that site. They will compare this data with other sites they have, and with uninoculated waddles as the controls. 

The oyster mushroom spawn that was used in this experiment is very specific. The CoRenewal team is introducing a fungi that is native to the area. They got it from a local mushroom grower in Moss Landing. 

“We grow 12 different varieties of mushrooms. We do shiitake, tree oyster lion's mane, maitake, king trumpet, cinnamon caps, many varieties, pink and yellow oyster,” said Kyle Garrone, the production manager at Far West Fungi. 

Garrone said Moss Landing is the ideal place to grow mushrooms because of the humidity, and the climate that doesn’t fluctuate too much.


Credit Michelle Loxton.
Rows of pink oyster mushrooms grow in a shipping container at Far West Fungi in Moss Landing. Kyle Garrone, the production manager, said this location on the Monterey Bay is the perfect place to grow mushrooms.

On a tour of the facility, you can see pink and yellow oyster mushrooms growing inside different shipping containers under a gentle spray of irrigated water. 

“They have a really nice, crazy looking color that most people think like, oh, what did you do with these mushrooms?” he said. 

Garrone said Far West Fungi donated the native mushroom spawn for this experiment to do their part in helping the community deal with the toxic consequences from last summer’s wildfire.


Garrone with some of the mushrooms they grow.


Gregory Gilbert, a mycologist and professor of Environmental Studies at UC Santa Cruz says fungi have been used to remove toxins for decades.

“But it's not as extensively studied as it probably could be or should be,” Gilbert added. 

He said because fungi live inside what they eat, some of them have this amazing ability to take in toxins and either use it for energy or convert it into something less toxic. 

“Now it depends on the fungi. It depends on the toxins. it's not a universal fix for everything,” said Gilbert. 

Gilbert said mushrooms and fungi are tremendously diverse in what they can do. Abilities scientists continue to study. Like the healing of wildfire burn scars. 

Far West Fungi and UC Santa Cruz are two of the many organizations that support KAZU.


From 2019 to 2021 Michelle Loxton worked at KAZU as an All Things Considered host and reporter. During that time she reported on a variety of topics from the coronavirus pandemic, the opioid epidemic and local elections. Loxton was part of the news team that won a Regional Edward R. Murrow Award for the continued coverage of the four major wildfires that engulfed California’s Central Coast in 2020.