The Wisconsin DNR is investigating a significant fish die-off at a Manitowoc lake.
Manitowoc Fisheries Biologist Jason Breeggemann said in a statement that he received a call on Monday afternoon from a resident who lives and fishes on the lake, who reported that he was no longer seeing any fish on the electronics he used.
The fisher also told Breeggemann that all the minnows he was using for bait were dead when he pulled them up for fishing.
Breeggemann and Water Resources Biologist Claire Hetzel went to Silver Lake on Tuesday and found very low oxygen levels at 12 of the locations where they drilled holes through the eastern and western basins of Silver Lake.
They also observed dead panfish, such as bluegills, on the bottom of the lake along the western and southern shores of the western basin.
Breeggemann says he spoke with several residents and anglers over the last two days as part of the investigation, and none of them observed any direct discharges into the lake in recent weeks. There were also no reports of any unusual smells, such as sulfur or manure.
The DNR biologist notes that Silver Lake has a history of winter killing, with the last one reported in the winter of 2014-2015.
It was later determined that it was only a partial kill. Because of how thick the ice is on Silver Lake, Breeggemann says his team will conduct a fish survey in the spring to look at the extent of the kill.
