by CHRIS ROGERS
As the investigation into a fish kill on one of Winona County’s premier trout streams continues, local residents expressed their frustrations at last week’s County Board meeting. It is the third major fish kill in the county since 2015, and some residents criticized the state and county for failing to identify the causes or hold anyone accountable for past fish kills, while others said the government needs to do more to prevent the next fish kill. Also last week, state agencies announced they are contacting over 100 neighboring landowners as part of the investigation.
Over 2,500 fish — including trout as large as 27 inches — were found dead on Rush Creek south of Lewiston in late July. Minnesota Trout Unlimited said a member reported the kill late on July 25. State agencies responded on July 26. “We believe the fish had been dead for quite some time before we went out and investigated,” said Winona County Feedlot Officer Carly McGinty, who is assisting the state investigation. “All the fish were already on the bottom covered in silt primarily.”
McGinty and state investigators suspect runoff from a two-inch rainfall on July 23 may have caused the fish kill. “That’s when we think this happened,” she said.
“The fish kill actually happened north or upstream of the County Road 29 bridge,” McGinty continued. “We think it happened on the south tributary, not the north tributary.” County Road 29 crosses Rush Creek just northwest of the Enterprise Valley rest stop on I-90, about 2.5 miles south of Lewiston. The southern tributary extends west, toward land south of Utica.
Exactly what pollutants caused the kill is unclear. “Our agencies have collected water quality samples and are awaiting results,” Minnesota Pollution Control Agency, Department of Agriculture, and Department of Natural Resources staff wrote in a joint statement. “We have also gathered samples of the macroinvertebrate community from four different locations near the fish kill and are reaching out to more than 100 landowners located within a 10-square-mile area upstream of the fish kill for more information. We are asking landowners to provide detailed information about the type, rate, timing, and location of manure and pesticide applications on their property.” McGinty said she had collected manure management records from over 60 farmers as part of the investigation.
The state agencies declined interview requests, citing the ongoing investigation.
Studying stream-bed invertebrates can provide some clues, as can fish autopsies. However, the agencies’ investigations into past fish kills — one on Garvin Brook in 2019 and an event that killed nearly 10,000 fish on the South Fork of the Whitewater River in 2015 — were inconclusive. By the time water quality samples were taken, the pollutants had already washed downstream. To detect the chemicals responsible, it would have been necessary to take water samples as the fish kill was happening, the agencies reported in 2019.
“There was also an ethanol spill that happened on [July 23],” McGinty said, referring to a tanker truck that crashed and spilled fuel at the intersection of county roads 33 and 6 the same day as the big rainfall. “An ethanol tanker flipped over in the watershed, so that could be contributing, but we don’t know precisely what happened [to cause the fish kill] right now.”
That spill happened south of I-90, and a ridge appears to separate the location of the spill and the tributary where investigators believe the kill originated.
“We value and love our trout,” rural Lewiston resident Barb Nelson said. Referring to 25-inch-plus fish found dead, she said, “Most people who are lucky even to catch something that size, they wouldn’t eat it. They would just return it to let someone else have the excitement of catching it.”
Nelson continued, “The poor fisherman who takes one over the limit, he pays for that doesn’t he? Who is going to pay for 2,500 trout? … We’re expecting answers this time. We’re sick and tired of hearing everything is inconclusive.”
“Unfortunately, this isn’t a one-time occurrence,” rural Altura resident Melia Haugen said. “Mass fish kills like this are becoming like clockwork in our area. If we do nothing and nothing changes, we can almost guarantee it will happen again about the same time next year.”
“I’m exceedingly disappointed with the state response to this because they keep trying to target an individual,” Elba Township resident and geologist Jeff Broberg said. “This is a systems problem.” The three fish kills, he said, all have some similarities: They happened in mid- to late summer, when manure applications, herbicide applications, and intense rain events coincided. No one wants to be responsible for a fish kill like this, and obviously plenty of farmers manage their land without these problems, he said. There should be a warning system for landowners when big rain events are in the forecast, he argued. “We need [a philosophy] of prevention, not retribution,” he said.