Zebra mussel research underway in Pelican Lake in Crow Wing County
Juvenile zebra mussels may be more susceptible to treatments than first expected.
Zebra mussels research on Pelican Lake by the Minnesota Aquatic Invasive Species Research Center is showing results that may be more favorable than previously expected.
" If we use less product there are fewer unintended consequences and it is cheaper. So it's kind of a win-win. "
— Angelique Dahlberg.
Researchers working out of a mobile lab on Pelican Lake are studying the results of a 2019 treatment using a copper compound on zebra mussels of various ages. Results from previous tests suggest the compound may be more effective at lower concentrations than first anticipated. Researchers hope water tests and zebra mussel monitoring will reveal even more positive details.
"We found that concentrations and the duration of our treatments killed not only the juveniles but also the adults," Angelique Dahlberg, PhD student at the University of Minnesota, said. "And that suggests we could further decrease our concentrations. Because we're also killing adults, that means we have more than we need."
This is good news because it means less compound may be necessary.
"If we use less product there are fewer unintended consequences and it is cheaper," Dahlberg said. "So it's kind of a win-win."
The study so far is targeting juvenile zebra mussels, called veligers. The idea is that a treatment that prevents juvenile mussels from reaching sexual maturity will keep them from reproducing uncontrolled. Effectiveness of the treatment varies a great deal based on water pH, organic materials in the water, temperature and other factors.
Dahlberg clarified that the goal is not necessarily to wipe out zebra mussels.
"It's to bring the population down to a manageable level such that it's no longer causing a lot of negative impacts that people see, whether that be tons of shells washing up on the beach or changing fish habitats or things like that," Dahlberg said.
The mobile lab will remain at Pelican Lake through the end of July. The lab is observing the results of a 10-day exposure with a post-exposure period to follow. Results are expected in mid-winter, though they might not be available for the public until spring or later.
"It's tricky," Dahlberg said. "The USGS (United States Geological Survey) has a lot of different steps of review that data needs to go through before it's ever released. It's probably a little slower than other projects, but I'll probably start communicating about it next spring."
Pelican Lake was listed as infested with zebra mussels in 2012.
" It's to bring the population down to a manageable level such that it's no longer causing a lot of negative impacts that people see whether that be tons of shells washing up on the beach or changing fish habitats or things like that."
— Angelique Dahlberg.
The program is a collaboration between the University of Minnesota Aquatic Invasive Species Research Center and the United States Geological Survey. The program has gone as far back as 2016 involving other lakes such as Lake Minnetonka.
Travis Grimler is a staff writer for the Pineandlakes Echo Journal weekly newspaper in Pequot Lakes/Pine River. He may be reached at 218-855-5853 or firstname.lastname@example.org.