Since Paul Stamets’ TED talk “6 Ways Mushrooms Can Save the World” blew my mind back in 2008, I’ve watched the movement of using mushrooms for urban agriculture, pest control, medicine, soil remediation, and much more spread like mycelium through the green design community. So where has this long-deserved fungi renaissance taken us in the past few years since over 3 million views of Stamets’ propounding on the topic? Beyond the plentiful backyard mushroom farmers, mycoremediation—the use of fungi to break down or remove a range of pollutants from the environment—is being applied to contaminated sites to remediate a range of toxins, from typical stormwater runoff to industrial oil spills.
Some of the targeted pollutants which grass-roots guerillas and PhD academics alike have been experimenting with removing through mycoremediation include: polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), heavy metals, and fecal coliform bacteria. Various research projects have shown high percentages of removal of these contaminants from soil and water using various fungal species.
Fungal mycelia use enzymes and acids to break down elements of plant fiber and apply the same process to break down chemicals, especially components of petroleum, often into carbon dioxide and water. Many studies show the fruiting mushroom bodies don’t retain the toxic pollutants, but as in phytoremediation, it’s typically not recommended to combine mushroom farming for edible consumption and pollutant remediation, especially if heavy metals are present. However, the mushrooms and especially their substrate media are very valuable as compost after pollutants are processed.
While oyster mushrooms seem to be the current reigning champ for easy growing and broad mycoremediation application, Paul Stamets and others have found that certain mushroom species are better matched to particular pollutants than others in some cases. For example, turkey tails are well-suited to sequester mercury while the garden giant mushroom (Stropharia rugoso-annulata) proved superior for E. coli removal. Certain species have even degraded nerve gas and sarin. Some mushroom species such as oyster and turkey tails are found all over the world but, as in planting design, using native and non-invasive species well-suited to the site is critical for any successful project.
Mycelium can be applied directly to soil both for general soil health and remediation. Other successful methods Stamets has tested include inoculating straw and wood chip mulch with mycelium and spreading 4-12” deep; applying mycelium to mulch-filled erosion-control bags and placing rows of these to intercept stormwater, graywater, or agricultural runoff; and Stamets’ “Mycobooms”—or floating straw rafts containing mushroom mycelium employed to break down oil spills in water. Mushrooms growing in wet, moist climates where you would expect to see them may require less work; however there are also species adapted to desert climates. Mulch and other microclimate techniques to balance temperature, light, and moisture will help productivity.
Soil remediation techniques on contaminated sites such as removing, transporting, and incinerating soil can be extremely expensive. For applications such as removing PAHs accumulated in stormwater BMP media, mycoremediation is low-cost, low-maintenance, and ecologically regenerative. Beyond brownfields, fungi can be used in applications of ‘mycofiltration’ to prevent potential contaminants from entering sensitive habitats or ‘mycoforestry’ to help regenerate forests.
Perhaps the most outside the box thinking on mycroremediation comes from artist Jae Rhim Lee who proposes a “mushroom burial suit” to take the place of a coffin after death, remediating pollutants accumulated in our own bodies which would otherwise be released into the environment. If you’re interested in learning more, there are a plethora of recent resources on mycoremediation and other world-saving mushroom strategies. The list of resources below is just a start:
Cotter, Tradd. Organic Mushroom Farming and Mycoremediation: Simple to Advanced and Experimental Techniques for Indoor and Outdoor Cultivation. Chelsea Green Publishing, 2014.
Darwish, Leila. Earth Repair: A Grassroots Guide to Healing Toxic and Degraded Landscapes. New Society Publishers, 2013.
Fungi Perfecti LLC. 2016.
Lee, Jae Rhim. “My Mushroom Burial Suit.” TED Talk, July 2011.
Radical Mycology. 2016.
Stamets, Paul. “6 Ways Mushrooms Can Save the World.” TED Talk, March 2008.
Stamets, Paul. Mycelium Running. Berkeley: Ten Speed Press, 2005.
by Nicole Stern, ASLA, Ecology + Restoration PPN Co-Chair