KENAI — The Alaska Department of Fish and Game is moving forward with a project to eradicate the invasive northern pike from Kenai Peninsula waters.
The agency is planning to treat the Soldotna Creek mainstream with a piscicide called rotenone in June to get rid of the fish, with a second round of treatment planned for summer 2017, The Peninsula Clarion reported.
Fish and Game in 2014 treated several lakes in the Soldotna Creek drainage to eradicate pike, and fisheries biologist Rob Massengill said those efforts have proved successful.
"We went in and netted it and tested for pike DNA a half a year later after ice-out and we did not detect any pike," Massengill told the Soldotna City Council at its meeting on Wednesday. "Pike aren't able to get back in because we have a series of fish barriers preventing them from moving from Soldotna Creek back into that system."
Staff will use portable drip stations and backpack sprayers to inject rotenone into Soldotna Creek, according to a notice from Fish and Game published in December 2015. Some submerged wetlands near Sevena Lake and some sloughs along the creek corridor will require treatment via helicopter, the notice states.
At Wednesday's meeting, council members expressed concerns about rotenone's impact on fish in the Kenai River if it were to leave Soldotna Creek. Councilman Paul Whitney also asked about the safety of wildlife near the creek that may feed on the dead fish.
"It's not harmful to birds, mammals, people (or) plants at the concentrations we use for fishing management, which is around 40 to 50 parts per billion," Massengill said.
Massengill explained that the compound does not stay active in warm water for long. With both treatment phases set for the summer months, Massengill said, the rotenone is expected to be diluted by the time it reaches the Kenai River. Fish and Game also plans to use an oxidizing agent to neutralize the rotenone before it reaches the river.
The only creatures likely to be negatively affected by the project are zooplankton, a food source for small fish that has been known to decline heavily when exposed to rotenone. Massengill said the fish that feed on them won't be threatened.
About 30,000 native fish have already been taken from Soldotna Creek in preparation for the eradication. More are expected be removed this spring, most likely starting in early May.