At least 95 domestic sheep died after grazing inside a mothballed Monsanto Co. mine in southeastern Idaho, adding to the list of animal fatalities over the last two decades in the region’s rich but contaminated phosphate country.
Monsanto, which makes Roundup-brand herbicide from the phosphate it digs up in Idaho, announced the sheep deaths Oct. 12.
Company spokesman Trent Clark says the sheep died after eating plants in the Henry Mine, an open pit where mining stopped in 1989 but that remains the subject of Environmental Protection Agency cleanup oversight. A federal lab at Utah State University confirmed the sheep likely died after ingesting western aster, which accumulates selenium from contaminated soil.
Clark says a herder entered the pit with 1,200 sheep earlier this week without permission. According to Monsanto, the herder noticed several getting sick and moved them, but by then it was too late for 95 animals.
“We have already initiated preventative actions, including more clearly marked signage on fences and gates, and locked gates where appropriate,” the company said. “In addition, we will continue working with the rangeland plant specialists as part of a program of aster identification and control. Based on these remedies and conversations with the owner about best grazing practices in the future, needless losses of this kind will be avoided.”
Robert Ball, an owner of the Ball Brother’s Sheep Company whose animals died, didn’t return a phone call seeking comment.
Selenium is unearthed with phosphate in Idaho’s sparsely populated high country just southwest of Yellowstone National Park.
High concentrations of the element can be dangerous or deadly.
In 2009, for instance, eighteen cattle died near Idaho’s defunct Lanes Creek Mine where mineral rights were controlled by fertilizer-maker J.R. Simplot Co. — also after eating contaminated aster.
The health concerns extend beyond grazing animals.
Earlier this year, research commissioned by the J.R. Simplot Co. indicated a link between significant deformities in trout and selenium emitted from one of its Idaho phosphate mining operations. Some of the deformities included fish with two heads.
Monsanto’s Henry Mine operated for about 20 years before it was shuttered.
Three years ago, the St. Louis-based company signed an agreement with the EPA over a plan to investigate pollution at the site and two others and craft a comprehensive plan to remedy potentially harmful contamination.
At the time, EPA officials said that pact would provide a clearer picture of health risks to people, livestock and wildlife.
The sheep deaths announced Oct. 12 mark the first time Monsanto has acknowledged the deaths of animals at one of its mining sites.
An environmental group, the Greater Yellowstone Coalition, has challenged mining projects — including Monsanto’s operations. It continues to mine in the region, and is developing a big new mine nearby to supply factories that make Roundup.
A GYC representative in Idaho Falls didn’t immediately return a phone call on Oct. 12 on the latest sheep deaths.