BOISE -- Redwood Park Pond in Boise will be shut down starting immediately as Idaho Department of Fish and Game officers work to eradicate an invasive species of fish discovered inside it.
The pond will be dosed with a substance toxic to fish to kill off rosy red shiner, a type of minnow from the Midwestern US that is popular in aquariums. The shiner were illegally added to the pond, officials say.
Fish and Game officials say rosy red shiner are not native fish and have not been found anywhere else in Idaho. They want to keep it that way, according to Fish and Game fisheries manager Joe Kozfkay.
“We’ve seen firsthand the negative impacts illegally-introduced fish species can have on our native and sportfish species,” Kozfkay said in a statement. “We don’t want to take the risk of this species getting into other Idaho waters.”
The department plans to treat the pond with rotenone, a naturally-occurring substance that cuts of oxygen flow in fish. All the dead fish will then be removed from the water and taken to a landfill.
Redwood Park Pond will be closed to public use for two weeks after the treatment. Officials say the rotenone in the pond will break down in the sunlight and will be gone in a few weeks at most. The pond will be restocked with bluegill and largemouth bass next spring.
"The project is both expensive and time consuming and serves as a reminder to aquarium fish owners to be responsible and never dispose of aquarium fish in local waters," officials wrote in a release.
Fish and Game says anyone with aquarium fish they no longer want should take them back to a pet store, give them away to a responsible aquarium owner, or euthanize them as a last resort.
"Dumping them in the wild is never the right answer," Kozfkay said. "It forces us to do things like this where we have to literally kill thousands of fish today because somebody tried to save the life of an aquarium fish."