SHOREWOOD, Minn. (WCCO) — It’s been the most tested, controlled and, at times, controversial undertaking aimed at keeping an aquatic threat out of a Minnesota lake.
The fear of a zebra mussel invasion in Shorewood’s Christmas Lake has been a priority of area residents for the past several years.
But on Aug. 16, the fear was realized when the Minnesota Department of Natural Resources confirmed a small infestation of zebra mussels near the public access on the lake’s northwest corner.
That meant a battle was on to quickly eradicate the invasive species before they could spread any wider.
On Friday, the effort picked up more speed as a contractor began the job of finishing off what two prior treatments began.
The bullets in this battle are frozen bags of the granular chemical, potassium chloride.
It is also known as potash fertilizer, and it is the DNR’s latest weapon in the fight to stop the spread of zebra mussels.
“It interferes with the gill respiration of specifically, mollusks. It doesn’t target fish or any other aquatic organisms,” DNR invasive species specialist, Keegan Lund, said.
When the first zebra mussels were identified in the lake the boat landing was curtained off in an effort to isolate the damage. Soon after, treatments began with the pesticide Zequanox, followed by a treatment of a copper-based algaecide.
Both treatments appeared successful, but the infestation was later determined to be slightly larger and outside the curtain.
“We remain hopeful that we’ve got all of them,” Minnehaha Creek Watershed District’s Craig Dawson said.
To make certain that the invader is gone from the lake a contracted crew spent the day pumping a potash slurry down holes drilled through the ice. The solution should suffocate any mussels that remain in the area.
“Did we kill the mussels in the area or will we find mussels out in the lake? Finding every zebra in a lake this size is a difficult process,” Lund said.
While the treatment should kill isolated infestations, experts caution that it would be far too costly to try such treatments on larger lakes, such as the zebra mussel infested Lake Minnetonka.
“We’ll know next spring when we get divers in the water to see if we’re successful,” Lund said.
For now, fingers remain crossed in hopes of a zebra-free gift to the waters of Christmas Lake.
The process employed by the DNR has only been used twice before in Texas and Canada.
Both applications were successful but on far different bodies of water. One was a quarry pond and the other a stream.