YELLOWSTONE NATIONAL PARK — In this week’s Caldera Chronicles column, Yellowstone Volcano Observatory’s Scientist-in-Charge Michael Poland discusses the background of Mushroom Pool, a “nondescript” hot spring that has had a big impact on science.
According to Poland, Mushroom Pool is a small hot spring in Yellowstone National Park’s (YNP) Lower Geyser Basin. The pool is thought to have received its name in the 1890s due to its appearance or the presence of algae and bacteria. Despite being an ordinary pool in YNP, Mushroom Pool set a standard for how scientific research is completed in the park.
The weekly column recounts the story of Dr. Thomas Brock, a microbiologist who vacationed to YNP in 1964. Intrigued by the life forms thriving in the park’s hot springs, he moved to the area with his wife Louise (who was also a microbiologist) to study bacterial colonization. In 1966, Dr. Brock along with undergraduate student Hudson Freeze collected samples of bacteria from various springs, including from Mushroom Pool.
“A month later, back in the laboratory, Freeze managed to isolate bacteria from the Mushroom Pool sample — a bacteria now known as Thermus aquaticus (nicknamed ‘Taq’) for the warm water in which it lived,” Poland wrote. “They published their findings in the Journal of Bacteriology in 1969 and cataloged the bacteria in the American Type Culture Collection — a sort of repository for microorganisms.”
In 1983, biochemist Kary Mullis in Berkely, California, discovered that Thermus aquaticus contained heat-resistant elements that proved essential for modern DNA sequencing. The technique for DNA analyses that came from Thermus aquaticus is used today for crime scene investigations, genetic testing, medical diagnoses and more. Mullis received the Nobel Prize in 1993 for his work, and Brock and Freeze received a Golden Goose Award from the American Association for the Advancement of Science in 2013.
The Caldera Chronicle installment questions why Brock and Freeze focused on Mushroom Pool instead of a more “charismatic” pool like Morning Glory or Grand Prismatic. The answer lies in Brock’s leave-no-trace ethos. In order to collect biological samples from a hot spring, scientists must often leave their equipment on site and undisturbed for days or months. Mushroom Pool was not near a boardwalk nor was it a typical visitor destination, though it was close to the road for research access.
“Although Brock had a research permit, guidance on how to work in delicate areas was lacking,” Poland wrote. “Brock became one of the first to advocate for leaving locations as they were found — to ensure research equipment was not obvious and that all signs of the work were removed when the research was done.” Scientists in YNP now follow this standard while working in the park.
