Local biologists and fishery officials will experiment this summer on a new way to control invasive northern pike populations using technologies described as a water cannon and an electric fence.
In mid-June, Cook Inlet Aquaculture Association officials will test electric fence technologies developed to control fish movement with the Alaska Department of Fish and Game, which is in the last year of a three-year "water cannon" technology study. Fish and Game's work is in partnership with the U.S. Geological Survey.
The water cannon device is lowered into the water and shoots out a high-pressure wave. It has been effective in herding northern pike into an area or even killing them, said Pat Shields, Alaska Department of Fish and Game biologist.
"It would be like taking a big squirt gun and shooting a blast of water under the water and that's what this device does," Shields said.
Officials are hoping the two technologies might combine and form a new, effective method for controlling or eradicating populations of northern pike on the Kenai Peninsula and other areas across Alaska, Shields said.
This June's testing will be at Derks Lake, an isolated body of water located near Mackey Lake, with a northern pike population, Shields said.
Currently, numerous projects are being conducted to remove invasive northern pike from Southcentral waters including gillnetting, draining lakes or using the fish-killing chemical rotenone, according to Fish and Game's website.
Pike are aggressive and fish-eating predators. According to Fish and Game, trout, salmon and other fish have not had time to adapt defenses against the pike outside its native range, which includes Northwestern Alaska. Pike live in highly vegetated, shallow areas where they can ambush prey.
There are fewer deep water refuges in Southcentral lakes for other fish to hide from pike. According to Fish and Game, some rivers, streams and lakes that once supported silver and king salmon and rainbow trout now only have small pike populations.
Fish and Game listed 13 lakes and rivers with either known or reported and not confirmed populations of northern pike on the Kenai Peninsula.
"So what we are going to do this year is ... net off an area in the same lake we have been working on, put some pike in there, then put the fence in the middle of the net and then force the pike to come into contact with the electrical barrier and see what they do," Shields said. "Will they go past the electrical fence, is their behavior predictable, is it something that we can observe and see if they do everything under their power to avoid it?"
Amy Shaw, biologist for CIAA, said the electric fence technology might have a number of applications other than the June project.
"The technology is not new, but using it in this manner around here for herding northern pike and seeing if you can use it in conjunction with other methods of control definitely hasn't been tried around here," Shaw said.
Shaw said she was excited by the prospect of getting a better handle on northern pike populations through newer technologies. Advances made on the Kenai Peninsula would ultimately benefit other areas struggling with pike such as the Susitna River drainage and the Anchorage Bowl. The possibilities are numerous, she said.
"Anything you can dream of, basically," she said. "It could be used to corral fish in a certain area, potentially you could set up gillnets across one side of it and herd them into the gillnets if you are trying to do mass removal from a spawning bed or you could potentially keep them out of certain areas for some periods of time."
Brian Smith can be reached at firstname.lastname@example.org.