Whirling disease detected in Wisconsin, WDNR update on PFAS

By Steve Van Kooten

When the Prairie du Chien Area Arts Center hosted a Wisconsin Conservation Congress (WCC) hearing on the evening of April 8, Patrick Short, a Wisconsin Department of Natural Resources (WDNR) fisheries biologist, presented reports on wildlife disease, water contaminants and budget deficits to the public.

Budget deficit

Short reviewed a budget report for the fish and wildlife account, which is at a structural deficit. The WDNR uses the account to pay a significant portion of its workforce as well as many wildlife management programs.

“We’re not taking in enough money to pay our bills,” said Short. “We may have enough right now, but, eventually, over the next biennium, we’re not going to.”

A decrease in hunting and fishing license sales and inflation of operating costs have contributed to the impending shortfall. The report said operating costs had increased 59 percent since 2005, which is the last time fees for “most license products” increased.

Discounts, exemptions and waiver issuances also gouged an estimated $17 million per year from the account’s revenue.

To address the deficit, the 2023–25 biennial budget used a $25 million revenue transfer from the forestry account and an expected $2.2 million from fee increases for some nonresident license products.

The budget report concluded the revenue infusion from the forestry account would be a temporary fix as the agency reviewed options to rebalance the account in the 2025 biennium.

Parasite found

In March, a fishery in Langlade County discovered a microscopic parasite called Myxobolus cerebralis.

“They tested the sediment above and below the hatchery, and it was in the sediment,” said Short.

The parasite, which most severely affects rainbow trout, brook trout and salmon, can manifest as whirling disease, a condition that damages the fish’s nervous system and causes deformities and blacked tail fins.

“It affects the brain, the cartilage around the head and backbone, and basically makes it swim in a whirling type of motion, hence the name,” said Short.

While some species are acutely susceptible to the parasite, many infected fish never exhibit any signs of the disease. A few species, including brown trout, coho and chinook salmon, are considered moderately susceptible.

According to the WDNR, whirling disease and the parasite do not cause harmful effects in non-fish species, including humans.

A fact sheet distributed by the WDNR said it is inconclusive whether whirling disease will have a significant effect on Wisconsin’s trout and salmon populations.

The parasite spreads when infected fish, water, aquatic vegetation or mud are introduced to new bodies of water. The spores remain in the environment for years, and there is not a known treatment once the parasite infests a body of water.

The WDNR suggested several precautions to curtail the parasite’s spread, including to never bring in fish from different water bodies and to use hard-bottom waders in trout streams.

“The best thing you can do when you’re moving stream-to-stream is to clean your gear,” said Short.

He said bleach, sunlight and time were the best ways to clean and sanitize boats, equipment and fishing gear before moving to a new body of water.

PFAS

Short provided an update on WDNR measures to address the deposit of polyfluoroalkyl substances (PFAS) in Wisconsin waters.

PFAS are human-made chemicals from products as far-ranging as non-stick cookware, water-resistant clothing, cosmetics and some firefighting foams that can accumulate in humans, animals and plants, causing adverse health effects, such as cancer and liver disease. These chemicals do not break down in the environment. The WDNR has detected deposits of PFAS in the ground, surface and drinking water in different areas of Wisconsin.

The WDNR has designated more than 80 locations as remediation and redevelopment sites to track PFAS, issued fish consumption advisories in 24 waterbodies across the state, sampled approximately 2,000 public water systems and collected data from lakes and rivers to coordinate sampling plans.

The WDNR issued water quality standards for drinking and surface water, both of which came into effect in August 2022. Legislative action is necessary to enact groundwater standards after an impact analysis estimated costs to exceed $10 million over the next two years.

The state’s 2023–25 budget allocated $125 million to combat PFAS contamination. According to the DNR, the funds haven’t been released to the agency for use as of April 2024.

The WDNR offers an interactive data viewer to track PFAS deposits in Wisconsin. It can be viewed at https://dnr.wisconsin.gov/topic/PFAS/DataViewer.

Other business

• the WDNR surveyed the Mississippi River’s Pool 9 walleye and sauger population. During a five-day period in October 2023, workers collected 56 walleye and 31 saugers per hour. A similar study collected 92 walleye and 66 saugers per hour in Pool 10 near Lynxville. The report concluded walleye have reproduced at an above average rate since 2020 and saugers have reproduced at an above average rate for two out of the last three years.