Click the link to read the article on the WyoFile website (Mike Koshmrl):
SHOSHONE NATIONAL FOREST—Kelsee Hurshman stepped carefully into the shallows of subalpine Upper Brooks Lake high in the Absaroka Range.
The lake bottom was muck, and the water looked nasty — pea soup colored, with a bunch of floating thingies. The green, detritus-filled cove was nothing a healthy person would think of drinking from, but a thirsty dog probably wouldn’t hesitate. And this is just what the Wyoming Department of Environmental Quality employee from Cheyenne was looking for.
The 9,100-foot-high backcountry basin has a history of harmful cyanobacterial — commonly called blue-green algae — blooms. Officials advised the public of a bloom, starting on Aug. 24. Wading in about a month later, Hurshman sought to see if the water contained enough cyanobacteria-associated toxins to warrant an additional advisory.
“I’m collecting a few different samples,” said Hurshman, DEQ’s harmful cyanobacteria coordinator. Quickly and quietly, she bottled up the algae-choked water.
It was Sept. 20, and Hurshman was sampling with a couple DEQ colleagues and Shoshone National Forest hydrologist Gwen Gerber. The team logged the species of cyanobacteria present, where it was in the water column (the surface) and its color (green).
Over the course of the day, they’d hike by all the named lakes in the small watershed pressed up against the Continental Divide: first, Brooks Lake, then Upper Brooks, Rainbow and Lower and Upper Jade lakes.
Rimmed by Sublette Peak, the Breccia Cliffs and the Pinnacle Buttes, the stunning chain of lakes lies entirely in the national forest. They are remote, usually free from human presence and appear pristine. At a glance, one would never associate these picture-postcard-worthy high-altitude lakes with contamination. Yet they are dogged by nutrient problems and cyanobacteria blooms.
“All of the named lakes have had blooms over advisory levels,” Gerber said, “and two of them have had toxins over advisory levels.”
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.
Late last October, the Wyoming Department of Health issued a recreation advisory for the Wind River after a 10-pound puppy died within minutes of drinking flowing river water near the Upper Wind River Campground. Campers be forewarned: there are fall 2023 cyanobacteria toxin advisories in place for both the upper and lower Wind River campgrounds, plus in the Wind River immediately below Boysen Reservoir and two areas in the reservoir itself.
“It sounded like the animal wasn’t taken to the vet because the dog died so quickly,” Lindsay Patterson, DEQ’s surface water quality standards coordinator, said of the 2022 puppy death.
Those types of fast-acting cyanobacteria dog deaths can happen when canines ingest chunks of “mat-forming blooms.” Water quality specialists don’t know if one of the harmful mats came off Boysen Reservoir, flowed past the dam and stayed intact enough to still be deadly when the puppy encountered it a mile downstream, or if the mat formed in the Wind River itself.
Late summer and early fall are typically when cyanobacterial blooms are most likely to occur, but that’s not always the case.
In December of 2021, ice fisherman augering through a frozen-over Keyhole Reservoir came into a blue-green algae bloom. Three months later DEQ officials were still able to sample cyanobacteria in densities that exceeded the recreational standard.
“We went back and looked at the satellite imagery from before and it looked really, really bad,” Hurshman said. “We suspect it may have persisted.”
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?
