"Whoever did that ... their mothers didn't raise them right," Allen told Boise Weekly
. "That's as polite as I can be."
Allen is frustrated because the handful of bullheads originally dumped into the reservoir have proliferated. Now, they're having a negative effect on the lake's trout populations, and fisherman often catch the bullheads and complain to Fish and Game. Getting rid of the fish is a huge ordeal that will involve draining Horsethief Reservoir entirely this fall.
Before then, though, Fish and Game has opened the lake for "fish salvage," meaning there is no limit to how many fish people can catch and take: Usually, the limit is set at six fish per person per day.
Temporarily removing that restriction at Horsethief will help get rid of many of the fish before the lake is drained. Anglers must have a valid Idaho fishing license
, and the salvage will run Saturday, July 18, through Tuesday, October 20.
Fish and Game will begin draining the 500-acre lake on Tuesday, Sept. 8, when the angling season is nearly over. Allen said it will take 45 days for the reservoir to drain into the Payette River.
"We lose fishing time and the winter fishery," he said. "It won't fill up until spring from the snowpack. Hopefully it fills."
Allen figures about 1,000 trout will be lost in the lake draining process, but he purposely stocked it light this year because he knew they'd be draining the lake to eliminate the bullheads. The small amount of water that remains in the bottom will be treated with rotenone, which will kill the remaining fish. Rotenone dissipates naturally in a few weeks and appears to be harmless to livestock, wildlife, people and pets.
Once the lake refills, the department will restock it with rainbow trout and brown trout.
This isn't the first time Horsethief Reservoir has needed to be drained due to an invasive fish population. In 2006, Fish and Game did the same thing when yellow perch took over.
"It's frustrating to have to spend any sportsmen's dollars in this manner because of a thoughtless, criminal act by one person," Allen said in a Fish and Game news release
According to a 2011 Fish and Game economic survey, the total annual spending by anglers associated with Horsethief Reservoir topped $4.5 million with more than 26,400 fishing trips in a year.
About five years ago, a handful of big, bullhead fish got into Horsethief Reservoir—a lake nine miles outside of Cascade best known for the YMCA summer camp on its banks. Dale Allen, the regional fisheries manager for the Idaho Department of Fish and Game in McCall, can't speculate as to why the fish were illegally introduced into the lake, but he thinks they probably got there via a cooler or a bucket.