Will persistent snowpack mean winter kill in some lakes?
This winter's snowpack has covered area lakes like a tight-fitting lid for roughly four months
SPICER — A persistent snowpack has covered area lakes like a tight-fitting lid for four months now and has many anglers wondering.
Will we see winter kill in some of our shallow lakes?
“It’s an unanswerable question right now,” said Dave Coahran, fisheries supervisor with the Minnesota Department of Natural Resources in Spicer.
The potential for partial winter kill exists. The fisheries crew is monitoring area lakes and has seen oxygen levels decline through the winter. The heavy snow cover prevents sunlight from reaching aquatic plants under the ice that would otherwise help replenish some of the oxygen that is naturally depleted through the course of the winter.
In Kandiyohi County, the shallow waters of Lake Lillian, Ella and Wakanda are usually the most vulnerable to partial winter kill during years like this, according to the fisheries supervisor. Minnetonga, Swenson, Solomon and the Mill Pond above the dam in New London are also susceptible.
The fisheries office has received a few reports from anglers who said they saw some dead fish in Ella and Elizabeth lakes, suggesting they may have experienced a partial winter kill. This anecdotal evidence should not be cause for alarm. There are many years where the fisheries staff finds evidence of partial winter kills, but plenty of game fish remain and are waiting when they put nets in those lakes once the ice is out.
Elizabeth is a prime example. The fisheries supervisor said there have been years with partial winter kill. Yet come spring, the fisheries crew have pulled nets from its waters teeming with walleyes.
Even when partial kills occur, they can be difficult to confirm. Most of the water bodies in the region are connected and spring runoff triggers a lot of fish movement, explained Coahran. Fish populations can quickly fill any voids.
Partial winter kills that occur in the heart of winter can go unnoticed completely, he added.
Overall, it’s hard to assess just how hard this winter has been on the fish population. While we’ve had a persistent and deep snow pack, we experienced an unusual February thaw that allowed melt water to partially recharge some water bodies. Oxygen monitoring by the fisheries crew found some slight improvement in levels following the thaw, he said.
Sometime after ice out, possibly in early May, the fisheries crew will test net some of the lakes susceptible to winter kill to determine if it has occurred, according to the fisheries supervisor.
Like most, he’s anticipating a late ice out in the region. The median ice out date for most lakes in Kandiyohi county is around mid April. The latest ice out dates include May 4, 2013 on Norway Lake and May 8, 2013 on Green Lake, according to the Minnesota DNR.