LAKE WINNEBAGO, Wis. (WBAY) - Action 2 News has learned that DNR testing indicates a fish die-off on Lake Winnebago is due to viral hemorrhagic septicemia, a disease that's spread among susceptible species in the lake since 2006.
A dead fish floats on the surface of Lake Winnebago on April 25, 2018 (WBAY photo)
The DNR says most of the dead fish are sheepshead (freshwater drum), not game fish. This is important to note with the start of the fishing season for more types of fish this weekend.
"Based on current observations, fisheries biologists do not expect this die-off, which is primarily affecting fresh water drum, to have a significant effect on the Winnebago fishery," a statement from the DNR reads.
The DNR says hundreds of dead fish were found in the Fond du Lac area on April 24, and more were collected from Asylum Bay near Oshkosh and High Cliff State Park near Sherwood the following week. Complete test results to confirm VHS or other pathogens will take about four weeks.
Boaters need to follow the laws and practices that prevent the spread of invasive species which will also help prevent the spread of pathogens. These include draining water and clearing aquatic plants from their boats. Click here DNR guidelines.
Upwards of 50 species of fish are vulnerable to VHS. Signs that a fish is infected include bleeding, bulging eyes, and bloated abdomens.
Infected fish are still safe to eat, according to the Wisconsin DNR website. The disease was first recorded in the 1930s, and there are no reports of a human becoming ill from it, according to the most recent information from 2015.
The fish kill coincided with white algae blooms on the western side of Lake Winnebago and a chemical spill into Oshkosh waterways last month. The DNR says the white algae turned out to be decaying blue-green and brown algae blooms, which followed heavy ice cover and snowmelt runoff into the lake. The chemical that flowed from an Oshkosh solvent company after a fire was harmless titanium dioxide -- a whitening agent used in paint and toothpaste.
Local fishing clubs still say the sheer number of dead fish continues to be concerning, especially as many anglers prepare to head out for Saturday's fishing opener.
"My personal opinion, I'm not going to eat any of the fish out of the lake, not until they figure out what's going on. I mean, further up river I will, like I said, Lake Winneconne, Poygan, even the Wolf River up towards Fremont I will, but not down here," said Sean Dadas, a member of the Paynes Point Hook & Spear Club.
Scott Engel of the Otter Street Fishing Club added, "Right now what we're hearing is, it's contained mostly to the sheepshead. I did hear there were a few crappies and a couple other species of fish, and that's most concerning. These are huge to our system, to the economy of this area."
DNR Fisheries Supervisor Kendall Kamke said, "We're hoping that conditions improve as far as water temperature rises, then the virus will become inactive again and things should settle down, but right now conditions are just such that this virus can be active and as we've seen it's affecting the fish."