Cyanobacteria in Wyoming: Toxic Mystery

Shoshone National Forest hydrologist Gwen Gerber and Wyoming Department of Environmental Quality staffers Kelsee Hurshman, Ron Steg and Jillian Scott check out the shoreline of Brooks Lake Creek just below the outflow from Upper Brooks Lake. Although the water flows through a remote, wild, high-altitude landscape, the watershed is plagued by potentially harmful algal blooms. (Mike Koshmrl/WyoFile)

The toxic mystery of Wyoming’s backcountry cyanobacteria blooms

Water quality specialists have found evidence of so-called blue-green algae blooms in rivers, frozen lakes and even in seemingly pristine subalpine watersheds. From Wyofile.

Many unknowns

A mysterious environmental influence — or combination of factors — is believed to be triggering the blooms. There are theories, but DEQ employee Ron Steg, who leads the agency’s Lander office, is clear: There’s no saying exactly why cyanobacteria are striking this area every summer.
“This particular watershed, the geology is high in phosphate,” Steg said. “It could be atmospheric deposition. We don’t know, and that’s why we are studying this.”
The DEQ is specifically examining what’s going on in the Brooks Lake watershed in detail because its 234-acre namesake lake has struggled with algal blooms that, on the worst occasions, have been implicated in fish kills so severe that fish went belly up miles downstream in the Wind River. Since 2018, Brooks Lake has occupied a slot on the Wyoming DEQ’s “impaired list.” At one time, fingers were pointed at Brooks Lake Lodge and its formerly surface-discharging sewage lagoon, but problems with nutrients and cyanobacterial blooms higher in the watershed have led to a more holistic investigation.
The Brooks Lake watershed, however, isn’t the only place in Wyoming where people and their pets are finding harmful cyanobacteria blooms in unlikely places.


Then there’s the backcountry. Cyanobacteria blooms are often associated with abundances of nutrients, like fertilizer from agriculture, and warm water typically found at lower elevations. So why are blooms showing up in places like Togwotee Pass?

Gerber, the Shoshone National Forest hydrologist, doesn’t have any firm answers, but she has noticed a trend within the 17 waterbodies on the national forest where cyanobacteria have been detected in high enough concentrations to warrant an advisory. All of them except for one, she said, are located in the Absaroka Volcanic formation — which suggests a component of the geology could be a contributing factor.

1 thought on “Cyanobacteria in Wyoming: Toxic Mystery”

Leave a Comment

Discover more from The Smokey Wire : National Forest News and Views

Subscribe now to keep reading and get access to the full archive.

Continue reading