A rare forest-dwelling mammal known as the fisher is likely having its populations poisoned by pesticides from illegal marijuana farms in the southern Sierra Nevada, according to Nature World News.
While the marijuana plant itself is not a threat to the fisher, the rat poison and pesticides placed in and around the crops of illegal farms are ingested by small forest creatures that the fishers eat, making them sick and thus threatening their survival.
The weasel-like mammal is about the size of a housecat and lives in the rugged portions of the Sierra Nevada. The mammal and is considered a rare, sensitive species by the U.S. Forest Service.
Researchers from the U.S. Forest Service's Pacific Southwest Research Station (PSW), University of California, Davis, University of California, Berkeley and the Integral Ecology Research Center conducted a new study which found evidence that female fishers have lower survival rates when living areas with more exposure to rodenticides and pesticides.
"In [illegal] marijuana cultivation sites, regulations regarding proper use of pesticides are completely ignored and multiple compounds are used to target any and all threats to the crop, including compounds illegal in the U.S.," wildlife biologist and study author Kathryn Purcell said in a statement.
The researchers wrote that there is a "strong, yet speculative" association between fisher mortality and marijuana growers. "Determining a cause and effect relationship would require novel testing procedures and either an experimental framework or an extremely challenging, logistically difficult collaboration between the scientific and law enforcement communities, given the inherent dangers of visiting and monitoring these sites," they said.
In addition, they reported that many dead or dying insects are often found wherever illegal marijuana grows.
