Could drought strand mussels again?

Frederica Freyberg:
Spring storms have pounded Wisconsin in recent weeks, but parts of the state are still experiencing a long-term drought that can cause problems for marine life that need high water levels to survive. “Here & Now” reporter Nathan Denzin has more on one species that has been hit particularly hard.

Ellen Voss:
We reached peak drought severity in September of last year.

Mark Cupp:
To just see that crash with almost no rain for a long time was very disturbing.

Nathan Denzin:
It’s been a very dry few years for Wisconsin.

Lisie Kitchel:
I started getting lots of phone calls from people saying there’s all these mussels out there and they’re, you know, they’re stranded there. They’re dying. What can we do?

Nathan Denzin:
It’s had a significant impact on a species we hardly think about.

Jean Unmuth:
I was no longer picking up a mussel and placing it gently in the water. I was throwing them as fast as I could.

Nathan Denzin:
Much of southern Wisconsin has been in a perpetual drought since about 2021, straining aquatic resources. Despite spring rains, drought is still hitting the southwestern part of the state right now near the Wisconsin River.

Mark Cupp:
We didn’t see much rain in the fall. Our usual fall rise did not occur. And then really, a paucity of snow, especially in northern Wisconsin.

Nathan Denzin:
Mark Cupp is the executive director of the Lower Wisconsin State Riverway Board, where he works with the Wisconsin River from Prairie du Sac to the Mississippi.

Mark Cupp:
With no snow, we didn’t see anything happen with our spring flow that we usually see.

Ellen Voss:
Droughts are very stressful to aquatic organisms as well.

Nathan Denzin:
Ellen Voss is the climate resilience director with the Wisconsin River Alliance.

Ellen Voss:
There’s just less space for the things that animals and plants and insects and everything else need to survive.

Nathan Denzin:
One animal that can be squeezed out by low water is mussels.

Lisie Kitchel:
They’re basically just, you know, a mollusk with two shells and they live in the rivers and lakes, rivers and streams of Wisconsin.

Nathan Denzin:
Lisie Kitchel is a mussel expert at the Wisconsin DNR.

Lisie Kitchel:
They don’t have a brain and they don’t have eyes. So they, you know, they can’t just figure out where the deeper water is.

Nathan Denzin:
She says there are tens of thousands of mussels on the bed of the Wisconsin River, including 40 different species.

Lisie Kitchel:
They filter as much as ten gallons of water a day per mussel and when there are hundreds of thousands of them, they really help purify the water.

Nathan Denzin:
But when the drought reached its peak in September, mussels started to wash up on shore banks.

Jean Unmuth:
What I was really looking for was actually historic artifacts because the water was so low, I’d never seen it this low in the time I’ve lived here.

Nathan Denzin:
Jean Unmuth is a retired DNR scientist who lives near the Wisconsin River in Prairie du Sac. She was the first person to contact experts when she saw stranded mussels.

Jean Unmuth:
Mussels are a huge part of the ecology of this river.

Nathan Denzin:
Because dams act as a barrier for some aquatic species, almost all of the mussels in the Wisconsin River can be found below Prairie du Sac.

Jean Unmuth:
So I thought, hey, I’d better ring the alarm.

Nathan Denzin:
The dam here is the last of 26 on the waterway.

Lisie Kitchel:
Because we had such a drought year, the dam did not have water to release.

Nathan Denzin:
Many of the dams on the Wisconsin, including Prairie du Sac, have strict federal regulations. While dams keep a reservoir of water on hand to generate electricity, federally regulated dams are not allowed to release more water than they receive.

Mark Cupp:
Whatever comes into Lake Wisconsin at the very head of the lake comes through the dam.

Nathan Denzin:
Those dams are called “run of river dams” because any water that comes in must go out. Alliant Energy, which owns the Prairie du Sac dam, in a statement said, “Our license requires us to maintain the water level. Therefore we cannot release more water during drought conditions. Not all dams on the Wisconsin River are licensed as “run of river” facilities and some may manipulate water levels.

Ellen Voss:
In this scenario on paper, nobody did anything wrong. Everybody was in their — in compliance with their license obligations the entire time. And yet the outcome was thousands or tens of thousands — we don’t know — dead mussels on the river.

Nathan Denzin:
That meant the only solution to save the mussels was to physically walk the shore banks and throw them back into the river.

Ellen Voss:
We put out a call to action just saying, we know that this is a problem. If you’re able to help, please go out to the river.

Jean Unmuth:
It was getting to where I was spending three to four hours — forget the artifacts — I was no longer looking at that.

Lisie Kitchel:
There were thousands of mussels saved. I mean, individuals were picking up a 100 mussels a day, 300 mussels a day. I mean, it was pretty amazing what people were willing to do.

Nathan Denzin:
Unmuth saved more than 1200 herself.

Jean Unmuth:
Multiple that times 365 days a year and just those 1200 mussels, you’re filtering like over 3 million gallons of water.

Mark Cupp:
I know that we made a difference and that will pay dividends down the road.

Nathan Denzin:
Extended forecasts for the summer show that for the fourth straight year, drought conditions are likely.

Mark Cupp:
Let’s just assume that we run into a similar situation and we don’t have rain, particularly in the northeast and central part of the state, then the answer would be easy, and that is yes, we will need to do mussel rescues again.

Ellen Voss:
There is a live, phone tree mussel rescue alert system in place.

Lisie Kitchel:
They can also contact me anytime and I can give them advice as to what to do.

Nathan Denzin:
Until the time comes to walk the shore banks again, experts’ eyes will be glued to the weather. For “Here & Now,” I’m Nathan Denzin in Prairie du Sac.