Dora Lake in Le Sueur County is dying.
The shallow, 732-acre lake has fallen victim to the winter of 2013-14 and with a severe winterkill imminent because of low oxygen levels, the Minnesota Department of Natural Resources has opened it to liberalized fishing through next Sunday, the day the inland waters fishing season for most gamefish closes.
That means anglers can use use just about means — with the exception of seines, hoop nets, fyke nets or explosives — to catch any species found in that shallow 6-foot-deep lake for personal use, no limits.
Hooks and lines are legal, of course. But so is spearing. Ditto for gill nets.
It has been a long winter and as a result, several other shallow lakes in the region may be poised to suffer winterkill, said Scott Mackenthun, assistant supervisor at the DNR’s Waterville Fisheries Office.
“This has been a tough winter, right up there with historically severe winters like those of 1995-96 and 2000-2001,” he said.
The early ice cover followed by uniform snow cover across the area has meant that many shallow lakes, even those equipped with aeration systems designed to prevent such occurrences, may experience some degree of winterkill.
Winterkill is a phenomenon where dissolved oxygen in the water falls to levels insufficient to support fish and other aquatic creatures, causing them to suffocate.
Typically, it is caused by the shutdown of the photosynthetic process of aquatic vegetation after heavy snow blocks out sunlight for extended periods. The process is exacerbated by the decomposition and decay of dying plants, which further deplete oxygen levels.
Mackenthun likened the process to a check book. “You’ve got credits and debits,” he said. “In the fall when the ice forms, the water is cold and is holding so much more oxygen — you’ve got all those credits.”