But about a month after the aquatic invasive species were found in Pelican Lake, it’s sorting out to be a good news/bad news proposition on the popular Brainerd area lake. And possibly more good news than bad, at least as of late.
Dan Swanson, DNR invasive species specialist in Brainerd, led an extensive inspection of the lake Aug. 1 for the presence of zebra mussel veligers.
“We took oxygen and temperature readings from the water surface to 44-foot depth,” Swanson said in the report Monday. “We then sampled five sites in Pelican Lake using a Wisconsin plankton net. We preserved the samples with alcohol and mailed the samples to Gary Montz at the DNR lab in St. Paul for analysis. Gary Montz looked at the water samples through a microscope on Aug. 6.
“He did not find any zebra mussel veligers in the samples.”
There is more reason for hope at Pelican. First, after a single juvenile mussel was found on a dock at the lake back in November, an intensive search that followed that month found nothing. And while the follow-up search this summer found the mussels in two different locations on the lake July 9, the DNR divers reportedly found just one zebra mussel in each location near Gooseberry Island, said Marc Bacigalupi, Brainerd area fisheries supervisor.
And while that was enough to declare the lake infested, there is another reason to be optimistic — the situation on Pelican isn’t as dire as it was on Gull Lake when the mussels were found there in October 2010; the infestation reportedly is continuing to grow on Gull.
A big reason for that is Pelican itself — it’s not as conducive as, say, Gull, to the mussels, Bacigalupi said.
“Pelican has got broad sand flats and sandy basins for the most part. Zebra mussels don’t settle on sand, they prefer a solid surface,” Bacigalupi said earlier this week.
And there’s more reason for “optimism,” he said. Although it should be guarded optimism at best, he said.
“We caught it at such an early stage. It’s three, four or five years behind Gull in the stage of infestation. It could explode in the next several years, but we caught it early and are taking steps to monitor it. We’re planning some water sampling, monitoring counts, actually monitoring the population itself. We hope the (zebra mussels) habitat is limited on Pelican. It’s been a unique case. But it’s hard to predict.”
As for if there are more zebra mussels in the lake, Bacigalupi said it’s likely “there’s a population somewhere in the lake. But it’s like a needle in a haystack — it (Pelican) is 8,300 acres.
“We believe there’s an apparent population out there that’s reproducing and drifting around and what we’re seeing is young adults that have settled out in an early state of infestation.”
So what now? According to Bacigalupi, because of the uniqueness of the situation, they’ll give it a bit different treatment than they might with, say, a Gull or other lake that is already past the point of no return.
“We came up with a tentative plan — we’re planning on more intensive monitoring than we do for a lot of lakes because as many lakes start popping up (with zebra mussels infestations) we won’t be able to carry out intensive monitoring on every lake. It would be overwhelming.
“Some of the benefits of Pelican is it might be the lowest productivity among inland infested waters. But if there are concerns of the food-chain effects — that’s what we’re concerned about.”
According to the DNR, educational and enforcement efforts to limit the spread of the mussels are increasing at the lake due to its designation as infested waters. Minnesota law prohibits the possession or transport of any aquatic invasive species in the state. According to the DNR, boaters and anglers must continue to take extra precautions when using this popular lake as zebra mussels could pose risks for other waters.