This single juvenile zebra mussel's size is shown compared to a penny. The mussel was reportedly found on a dock post in Pelican Lake.

"This is a unique situation where, after much effort, we cannot confirm the report," said Dan Swanson, DNR invasive species specialist in Brainerd.

"We're looking for information," he said. "If they saw something they thought was a zebra mussel, we want to hear about it."

Anyone with information to share can contact Swanson at 218-833-8645 or Daniel.Swanson@state.mn.us.

After a dock installer reported finding the zebra mussel on a dock, Swanson spent several days thoroughly checking boat lifts, docks, weed rollers and fish baskets on the northwest corner of Pelican Lake and found no other zebra mussels.

Swanson also inspected marker buoys that had been removed from the lake, but again found no zebra mussels.

In addition, Swanson talked to other dock service providers who removed hundreds of docks and lifts from Pelican Lake this fall, and all said they hadn't found any zebra mussels.

Swanson also inspected more than 50 docks and lifts on the south and east shores of Pelican Lake and found no zebra mussels.

The DNR wants to make sure it is not missing any information, so it shared news of the reported single zebra mussel to get the public's help.

The DNR plans to work closely with the Pelican Lake Association and the Pelican Lakes Conservation Club as well. It will resume an aggressive search in the spring, including having two certified DNR Scuba divers check the 8,300-acre lake.

Clyde Clement, a zebra mussel activist who lives on Pelican Lake, emphasized the need for lakeshore owners and lake visitors to be even more proactive in prevention and protection actions.

"We must protect Pelican Lake as if it is not infested," he said. "It's like you're innocent until proven guilty, and we've been unable to prove it guilty."

Clement noted that the average dock on Pelican Lake has 15 sections, each with two dock poles, and no zebra mussels were found on the more than 400 docks and lifts that were inspected.

"A young zebra mussel in a plastic bag is not proof that Pelican Lake is infested with zebra mussels," Clement said, citing the need to take more time to investigate the lake.

According to state statute, a lake will be designated as an infested water if it's been determined that the water contains a population of an aquatic invasive species that could spread to other waters if use of the water and related activities are not regulated to prevent this.

Swanson said when zebra mussels were first reported in other lakes, such as Gull Lake in 2010, the DNR was able to find other zebra mussels on vegetation or equipment to warrant the infested waters designation.

If no zebra mussels are found next summer in Pelican Lake, the next test will be in the fall when docks and boat lifts are pulled from the water again. Swanson and Clement noted the need to educate lake homeowners on what to look for.

They also noted the need to follow new laws that went into effect this year, including pulling boat plugs and draining bait buckets and live wells when leaving any lake and river in the state.

Zebra mussels are not native to area lakes and have ecological, recreational and industrial effects. They destroy food chains, filter water, clog pipes and engines, reproduce at a rapid rate and have sharp shells.

"It's imperative to continue and raise prevention efforts to stop the transfer of all waters and weeds from lake to lake," Clement said.