Spring ice is thawing earlier in lakes. What does that mean for life below the surface?

Summary

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Podcast Summary: Short Wave – "Spring ice is thawing earlier in lakes. What does that mean for life below the surface?"

Date: March 2, 2026
Hosts: Emily Kwong, Burleigh McCoy
Guest Experts: Zach Feiner (Fisheries Biologist, University of Wisconsin), David Van Lan (Longtime Fisher)

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Episode Overview

In this episode of NPR's Short Wave, hosts Emily Kwong and producer Burleigh McCoy dive into how climate change is causing ice on lakes to thaw earlier each spring, and what these shifting patterns mean for the aquatic life—and human recreation—below the surface. Through a firsthand ice fishing trip in Wisconsin with biologist Zach Feiner, they explore the cascading effects on fish populations, biodiversity, and local traditions, highlighting both ecological research and personal connections.

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Key Discussion Points and Insights

The Changing Landscape of Lake Ice

• Delayed and Shorter Ice Seasons:
  • Burleigh reports that, in Montana, the lake wasn’t safe enough to walk on until mid-January, much later than usual, impacting traditional ice fishing (01:00).
  • Ice fishing seasons have shortened significantly, with longtime fisher David Van Lan noting:

    "We've lost a good six weeks off of our ice fishing season since I started back in the 1980s. We used to start in December, end in April. Now we start in January, end in March."
    — David Van Lan (02:07)

• Impacts on Community:
  • Ice fishing is a major industry (1.7 million fishers in the US), and a shortened season affects livelihoods, recreation, and local economies (01:42).

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Ecological Consequences Below the Surface

• Disruption to Annual Rhythms:
  • Earlier or unpredictable thaws upset timing for aquatic ecosystems.
    • Zach Feiner explains:

      "The timing at which the lakes thaw in the spring has gotten really variable... from one year to the next is a two month difference."
      — Zach Feiner (05:15)

• Domino Effect in the Food Chain:
  • Earlier/more variable ice melts lead to:
    • Algae blooms timing shifts
    • Disrupted zooplankton populations (key food for young fish)
    • Mismatched timing can result in lower survival rates for fish like walleye (05:47–06:19)

  • "All those events start to get scrambled up and mistimed. So then your food web gets delinked or decoupled, and ultimately you end up with not having enough food around to feed small fish."
    — Zach Feiner (06:09)

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What This Means for Fish Populations

• Walleye as a Case Study:

  • Walleye, sensitive to these changes, spawning in spring—if food webs and temperatures are off, populations decline (05:38–06:34).
  • Some lakes require artificial stocking to maintain walleye populations:

    "There's a lot of lakes where walleye have declined really significantly, and now the only reason there are walleye in there is because we have to stock them."
    — Zach Feiner (10:28)

• Shift Toward Warm-Water Species:

  • On the fishing trip, the group catches bluegill and crappie—warm-water fish that are likely to fare better as waters warm (09:43, 10:09).
  • Conservationists and recreational fishers may have to shift their focus:

    "Maybe you decide to go fish for something else. Right. That might be more resilient to harvest, like a largemouth bass or bluegill that are more of a warm water fish."
    — Zach Feiner (11:59)

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Cultural & Personal Impacts

• Tradition versus Adaptation:
  • The potential cultural loss is real; asking fishing communities to switch target species is significant:

    "If you have this traditional connection to walleye, maybe that's a harder change to accept or to deal with."
    — Zach Feiner (11:27)

  • Emily draws a humorous yet poignant parallel:

    "There's so much sensitivity for these species that a difference that could seem small to us is actually life or death to them."
    — Emily Kwong (07:03)

• Local Action:
  • While individuals can’t stop global warming locally, they can make responsible choices:
    • Change fishing and harvesting practices
    • Advocate for aquatic habitat protection (11:59–12:44)

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Memorable Moments & Quotes

• On Changing Seasons:

  “We’ve lost a good six weeks off of our ice fishing season since I started back in the 1980s.”
  — David Van Lan (02:07)

• On Ecological Tipping Points:

  “All those events start to get scrambled up and mistimed. So then your food web gets delinked or decoupled…”
  — Zach Feiner (06:09)

• Personal Reflection:

  "There's so much sensitivity for these species that a difference that could seem small to us is actually life or death to them."
  — Emily Kwong (07:03)

• Resignation and Humor:

  “Did you ever get any walleye?”
  “I did, but not the way I wanted... I had it with some fried cheese curds, so no walleye. I'll just have to go back and maybe it'll be for a different kind of fish.”
  — Emily Kwong & Burleigh McCoy (12:44–13:00)

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Timestamps for Important Segments

• 00:24–02:29: Ice fishing season recap & impact on communities
• 05:07–06:34: How thaw timing changes disrupt food chains and walleye survival
• 07:39–08:51: Adapting lake life and ecology to diminished ice
• 10:28–11:08: Stocking fish and sustainability concerns
• 11:59–12:44: How communities can respond to ecological shifts
• 12:49–13:00: Burleigh’s walleye confession and fried cheese curds story

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Conclusion

This episode illuminates the complex, cascading consequences of earlier spring ice thaws for lakes: less fishing time, disrupted food webs, declining walleye, and a community confronted with cultural changes. Through humor and a personal lens, Emily and Burleigh make the science accessible—reminding listeners that while climate change is a global issue, its effects and solutions are deeply personal and local.

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Transcript

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[Emily Kwong]

Hi Short Wavers. Emily Kwong here with producer Burleigh McCoy and part two of her Changing Lake Ice reporting. Don't worry if you haven't listened to the other episode. You don't need to to appreciate this one.

[Burleigh McCoy]

Definitely not Emily. But quick recap. Last episode we talked about how changing ice conditions are making it less safe to be on the ice, which is true. Where I live in Montana, not only have there been warm spells which make the lake ice less safe, this year, ice wasn't safe enough to walk on until the second week of January. Wow. And Emily, you know how much I love to ice fish.

[Emily Kwong]

Yes, you live for ice fishing season, Burley.

[Burleigh McCoy]

I know. And so far this year that's been really tough here. So I recently went on a nice fishing trip with a fisheries biologist named Zach Feiner.

[Zach Feiner]

We'll say I did see one guy catch one here yesterday, so he threw it back. So there's at least one fish out there for us.

[Burleigh McCoy]

But Zach is in Madison, Wisconsin.

[Emily Kwong]

Wait, you left your family in Montana to go fishing all the way in Wisconsin?

[Burleigh McCoy]

In a heartbeat. There's just no commitment. More serious. But really, I wanted to get on the ice with Zach to talk about how lakes everywhere are losing ice and the impact that that's having on, like, ecosystems, from disrupting their food chains to lowering biodiversity.

[Emily Kwong]

Which could have a huge impact on your fishing way of life.

[Burleigh McCoy]

Exactly. Me and about 1.7 million other ice fishers in the U.S. ice fishing is a huge industry that generates millions of dollars through equipment sales and guide services. I talked to David Van Lan about how one of his favorite seasons, ice fishing, is shrinking. He grew up on a dairy farm south of Green Bay, Wisconsin, moved to Madison for work in 1971, and he says he's been fishing the area for decades.

[Zach Feiner]

We've lost a good six weeks off of our ice fishing season since I started back in the 1980s. We used to start in December, end in April. Now we start in January, end in March.

[Emily Kwong]

Today on the show, how losing lake ice is affecting life below the surface

[Burleigh McCoy]

and what that means for ecosystems and people who enjoy them.

[Emily Kwong]

You are listening to Short Wave, the science podcast from npr.

[Burleigh McCoy]

This message comes from Charles Schwab. When it comes to managing your wealth Schwab gives you more choices like full service, wealth management and advice when you need it. You can also invest on your own and trade on think or swim. Visit schwab.com to learn more.

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[Emily Kwong]

Short wave comes out four days a week. That's Monday, Tuesday, Wednesday, and Friday. So to make sure you never miss an episode, look for the Follow button on your podcast app and give it a tap. Thank you so much. Okay, Burleigh, let's get into this. How was this reporting trip to go fishing in Madison, Wisconsin?

[Burleigh McCoy]

It was packed. Zach picked me up at 5am early

[Emily Kwong]

bird gets the fish.

[Burleigh McCoy]

I'm Burley. Can I throw my stuff in the back?

[Zach Feiner]

Picked up some donuts.

[Emily Kwong]

Donuts are essential for ice fishing.

[Burleigh McCoy]

They are essential. We drove about 15 minutes south to Lake Wabisa to meet someone named Tom Sehosh.

[Zach Feiner]

He's a big walleye fisherman. He is the one who gave me the intel on this spot, and he's

[Burleigh McCoy]

actually probably already down there because I wanted to catch a walleye.

[Emily Kwong]

Is a walleye a fish?

[Burleigh McCoy]

Yes. They are one of potentially dozens of fish that are sensitive to changing lake ice. Their populations are doing okay right now in a lot of places, but biologists like Zach are keeping an eye on them because they spawn in the spring.

[Emily Kwong]

Oh yeah, that's when ice usually melts.

[Burleigh McCoy]

Exactly. And so a big part of what Zach tracks is that timing of the ice freezing and thawing.

[Zach Feiner]

And one of the parts of my research that has really jumped out is that the timing at which the lakes thaw in the spring has gotten really variable. So, for example, the earliest in recent years, the earliest the lake has thawed has been in the middle of March. And the latest lake has thaw has been in the middle of May. So from one year to the next is a two month difference.

[Emily Kwong]

That is a huge jump. What impact does that have on the fish?

[Burleigh McCoy]

Yeah, Zach says it breaks down the normal process of what happens when a lake thaws.

[Emily Kwong]

Can you describe that process?

[Burleigh McCoy]

Yeah, it's kind of a domino effect. So in springtime, when a frozen lake starts to get more sun and warmer temperatures, that kickstarts algae blooms in the water that feeds little critters called zooplankton. And those zooplankton are a really important food source for some fish. But if there are these massive differences in when spring starts, it messes up the whole system.

[Zach Feiner]

All those events start to get scrambled up and mistimed. So then your food web gets delinked or decoupled, and ultimately you end up with not having enough food around to feed small fish.

[Burleigh McCoy]

Zach's research has shown that in years with huge swings. And when the lake thaws, they don't count as many young walleyes the next fall. So fewer of them are surviving. Whoa. And the more that happens, eventually, the less walleye there will be for people to catch and take home.

[Zach Feiner]

And the important thing to point out is that while I've seen this in walleye, lots of other species are seasonal spawners. They spawn in the spring or in the fall. So you could see these effects probably happening for a lot of different species.

[Emily Kwong]

You know what I'm thinking about for some reason, listening to this?

[Burleigh McCoy]

Okay.

[Emily Kwong]

My cat is so sensitive to the slightest changes in dinner being served by a half hour. Like, and if it were a difference of months for his life cycle, I'm

[Burleigh McCoy]

sure Zuko would scream.

[Emily Kwong]

Yeah, Yeah. I hope I'm not making like a false comparison here. It's just like I'm appreciating. There's so much sensitivity for these species that a difference that could seem small to us is actually life or death to them.

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Yeah.

[Burleigh McCoy]

Especially if the food is just no longer there anymore. And this is true for lakes outside of Madison as well. Scientists are really just kind of starting to study this. So in our last episode, we talked about how many lakes have already lost weeks of ice coverage each winter season. And thousands are predicted to stop forming ice entirely before the end of the century. And these are lakes where the ecosystems have evolved to be icy in the winter.

[Emily Kwong]

Yeah. I've been wondering about this ever since your last story. What is the ecological impact for organisms that have adapted to live in an icy lake.

[Burleigh McCoy]

Yeah. I mean, walleye are this cool water species that could really suffer in the coming years as the climate continues to warm. And they're one of many where this could happen. Right. I really wanted to experience being on a walleye lake while they're still around and doing okay. So back at Lake Wabisa, we unloaded the fishing gear from the car in the neighborhood cul de sac. With just one house near the end

[Zach Feiner]

of the road, we are headed through here. The joys of urban ice fishing.

[Burleigh McCoy]

I followed Zach through the dark to a tall chain linked fence next to the house while he pulled the sled that had all the gear in it. After a few minutes, the tree lined path opened up to a dark open expanse with one green light in the distance. This is Tom?

[Zach Feiner]

Yep, I think so.

[Emily Kwong]

How great Gatsby of you. What was the green light?

[Burleigh McCoy]

It's a headlamp. So we had our headlamps on, we walked out onto the lake.

[Zach Feiner]

I'll see your face without a spotlight

[Burleigh McCoy]

in my eyes later. Oh, yeah, sorry about that.

[Zach Feiner]

No, no, everybody's got one. All the cool kids are wearing them.

[Burleigh McCoy]

Yeah. Zach sets up his insulated pop up tent and drills some holes in the ice to fish through. We've got some electronic machines to help us out. One is sonar that can tell you if something is moving in the water and where. Another is an underwater camera. Both of these things help you find fish.

[Emily Kwong]

So I'm picturing you all standing in the dark on this icy lake and there's a line down in the hole and you're like waiting.

[Burleigh McCoy]

We're watching the sonar because it looks like there's something down there. Does it look like it's still there?

[Zach Feiner]

It doesn't, unfortunately. That's the problem with fish. They move.

[Burleigh McCoy]

But eventually there it is.

[Zach Feiner]

Gonna find out. Got one? Yep. Blue gills.

[Emily Kwong]

Oh, a bluegill's fish. So not a walleye.

[Burleigh McCoy]

A bluegill? Yeah. Not a walleye. Zach says bluegill are a warm water fish and one that will probably do better in waters like these as climate change continues. So I take the fishing pole, give it a try.

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All right.

[Zach Feiner]

New species.

[Burleigh McCoy]

Oh, okay. I've never caught a crappie before.

[Emily Kwong]

Crappy. Not a bad word. Just a different type of fish.

[Burleigh McCoy]

Also a warm water fish, actually. And now as an avid ice fisher, I'm always looking for reasons why I'm not catching the fish that I want to catch. So I asked Zach if changing ice from year to year could be the reason we're not seeing walleye today.

[Zach Feiner]

It could Be one of the reasons why. Yeah, yeah, yeah. I mean, it's, it's tough. There's a lot of lakes where walleye have declined really significantly, and now the only reason there are walleye in there is because we have to stock them.

[Emily Kwong]

Stocking. Yes. I learned about this the one time I've. I went ice fishing in Maine. Stockings where humans are putting young fish in the lake.

[Burleigh McCoy]

Yeah. Often thousands, to keep up their numbers. It's done for conservation and for people like me who like to fish. And it happens in a ton of places, including the lake. I fish in the winter. Now, Zach says the question becomes, when do people stop stalking if a lot of those fish are just going to die?

[Emily Kwong]

Right. Like, are you setting them up for doom if you're putting them in a lake that is inhabitable for them?

[Burleigh McCoy]

Right. Like, if ice keeps shifting rapidly and significantly knocking down walleye populations, how long should people continue adding them back? And maybe, for example, switch to supporting warm water fish that people like to catch that would thrive in these warmer waters?

[Zach Feiner]

If you have this traditional connection to walleye, maybe that's a harder change to accept or to deal with.

[Emily Kwong]

This would be a big change for the fishing community to ask someone to do something that they've done their whole life differently. I guess climate change asks that of all of us. Does Zach have any idea, though, how people are going to handle going for warm water fish instead of these cold favorites?

[Burleigh McCoy]

Yeah. He says through surveys, he's found people have definitely noticed a change in lake ice, which is a big first step to get people to think about then how to make changes.

[Zach Feiner]

When you're faced with what to do about climate change, especially regard to, like, fish or other things, like, it's hard to, to control the amount of, like, carbon in the atmosphere right. At the local level, but you can think about the things you can control. Maybe that means you make different harvest decisions, you keep fewer walleye, maybe you decide to go fish for something else. Right. That might be more resilient to harvest, like a largemouth bass or bluegill that are more of a warm water fish.

[Emily Kwong]

This story is reminding me how people who fish and people who hunt are actually paying often more attention to the environment than most. So it's cool to be hearing this from them directly, you know?

[Burleigh McCoy]

Yeah, that's so true. And Zach says it may also get people to think about what else they can do to help lake systems, like protecting the habitat that certain fish like. Like walleye.

[Emily Kwong]

As for you, fisher Burley, did you ever get any walleye?

[Burleigh McCoy]

I did, but not the way I wanted. I'll have the fried Walley.

[Emily Kwong]

You got one served to you a different way on a plate.

[Burleigh McCoy]

I did. It was lovely. It was delicious. I had it with some fried cheese curds, so no walleye. I'll just have to go back and maybe it'll be for a different kind of fish.

[Emily Kwong]

If you liked this episode, do us a favor and share it with a friend, because your vote of confidence is actually what ensures we can keep making this program. I also suggest you check out part one of Burley's Changing Lake Ice series and gorgeous photos from Burley's fishing trip. We will link to them both in our show notes.

[Burleigh McCoy]

This episode was produced by Rachel Carlson, edited by our showrunner, Rebecca Ramirez, and fact checked by Tyler Jones. The audio engineer was Kwesi Lee.

[Emily Kwong]

I'm Emily Kwong.

[Burleigh McCoy]

And I'm Burleigh McCoy.

[Emily Kwong]

Thank you for listening to Short Wave from NPR.

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