Officials with the Minnehaha Creek Watershed District say a copper treatment to kill zebra mussels on Lake Minnewashta in the southwest metro has been successful — so far.
Zebra mussels were discovered near the lake's boat access last month. Eric Fieldseth, the watershed's aquatic invasive species program manager, said the copper treatment was applied to the entire "Little Minnie" bay — an area of about 29 acres.
"These are still pilot treatments. We're still learning on these treatments the whole rapid response approach, how effective it is," he said.
Fieldseth said he hopes the treatment works better than a similar treatment on nearby Christmas Lake. In that case, officials treated a smaller area of the lake only to see zebra mussels show up again. They have since spread in the lake.
Still, Fieldseth says he doesn't expect the population to spike from year to year because Christmas Lake has less algae, a food source for the mussels, than other lakes.
Both Minnewashta and Christmas Lake are located south of Lake Minnetonka, which is infested with zebra mussels.
The Lake Minnewashta treatment cost about $30,000.