All over the country, Trout Unlimited chapters and their volunteers are hard at work making the world a better place for trout and the anglers that pursue them. Through focused conservation efforts based on science, and a shared desire to improve local environments, we are seeing new boots in the water every day – taking on conservation and restoration projects with our favorite fish in mind.

Unfortunately, these efforts oftentimes go under the radar, and people rarely even understand who they have to thank for their pristine trout-waters, which may not exist without the work of these hard-working collectives. Today, we shine a light on Jake Lemon and Matthais Bonzo who are pioneering the use of drones to gather thermal images to identify the coolest spots in water systems, literally.

Ariel view of the Stealthcraft research raft and drone platform.

Flylords: Before we talk all things research, can you tell us a little bit about yourself and how you became involved with Trout Unlimited?

Jake Lemon

Jake Lemon: My name is Jake Lemon. I’m Trout Unlimited’s monitoring and community science manager and I’m based in Michigan. I grew up in Southern Indiana and I never caught a trout until I was 23 years old. I started as an AmeriCorps volunteer in Colorado with the Colorado Council of TU. I was just a kid who liked to kayak and chase largemouth bass who was trying to find a way to make that part of my work. I didn’t know anything about Trout Unlimited, but I found this job took it. And it’s been a good ride since then. I’ve been with TU since 2011, so over 10 years now.

Matthias Bonzo


Matthias Bonzo: I’m Matthias Bonzo. I’m a project coordinator for Trout Unlimited and based in Grand Rapids, Michigan. I’ve been with TU since 2018 when I saw this job posted as a seasonal job posting. That winter I applied for it, worked through the summer, and then was brought on part-time until 2020 when I was brought on full-time.


Flylords: So tell us about the research that you guys are conducting right now.

Jake Lemon: We are working on developing an in-house capacity to use thermal imaging in order to map water temperatures. We’ll be able to identify cold water inputs like small tributaries, groundwater seeps, and springs that put cold water into rivers around the state of Michigan. By mapping these cold-water inputs, we can better inform the restoration and protection work that we do.

Jake secures the camera to the drone at the boat launch.

Flylords: Are there other groups within Trout Unlimited doing this research?

Jake Lemon: We’re the only team who’s getting this up and running within Trout Unlimited in the United States. It’s kind of an emerging field. We’re serving as a technical resource for teams starting this process as we learn how to do it ourselves. It’s been fairly well tested within academia- there’s a bunch of papers out there that we’ve been reading on how to best do this.

We also work a lot with the Forest Service Geospatial Technology and Applications Center. They’re the experts within the Forest Service on remote sensing and have done some thermal imaging work. They’re one of our technical resources that we go to when we have questions about what are the best methods to use, how do we interpret this imagery and that sort of thing.

Jake and Matthias prepare the drone for take off.

Flylords: What inspired this whole program to start? 

Jake Lemon: I have a partnership with the Forest Service and we were doing some regional temperature monitoring and modeling. We looked into getting this done by another Forest Service unit who had the capacity to do so and we also looked into some consultants. After getting the quotes and looking into the cost of the equipment, I thought, ‘Well, if I could spend a year or two working on this, we could build out the in-house capacity to do it and buy all this equipment for less than what we would pay for a week of somebody else doing it for us.’

Then we could provide the service at a much more accessible cost for a Trout Unlimited chapter, a regional conservation organization, or a Forest Service unit at a cost that they could afford. We want to make this data more accessible to groups that are doing good on the groundwork in Michigan, and hopefully elsewhere as it grows.

The platform the drone lifts off and lands on is a sheet of plywood secured via slots on the raft.

Flylords: What are some difficulties you guys have experienced throughout this process?

Matthias Bonzo: Conditions. Finding the ideal conditions in order to get our best data has been our biggest challenge so far. Whether it’s leaves on the trees blocking imagery or it’s ice during the winter scarring the margins, we’ve really been trying to fine-tune the best time of year and the best time of day in order to get the best imagery possible.

Jake Lemon: There are probably four months out of the year that you can effectively do this and we have a lot to try to figure out. So that’s been part of what we are learning is dialing in what are the best conditions in which to do it. We’re trying to dial in how much effort we need to put into getting the spatial accuracy of the imagery. You could set out ground control points everywhere and have the accuracy down to the centimeter or you can do no ground control points and it’s maybe a couple of meters accuracy. We’re just trying to find how much accuracy we need to get the outcome that we want while being most efficient with our time. Because the less it takes us, the more ground we can cover and the more data we can get.

Every two seconds, the camera attached to the drone takes a photo. This screen displays the data that is captured with each shot. It also serves to fly the drone safely and accurately.

Flylords: What’s been the most enjoyable part about this whole process?

Jake Lemon: I love just diving in and learning about things that I knew nothing about. Before this, I had never piloted a drone. It was a black box of something that I knew nothing about.

Matthias Bonzo: Seeing different pieces of a river that we wouldn’t necessarily focus on otherwise. You have big rivers that get warm and going out and looking for the cold spots where the trout can still survive and seeing these pockets where you’re like, “Oh yeah, well, if we put a tree there, then maybe we could turn this into some amazing fish habitat.” Just seeing the potential on these larger warm water systems with some cold-water refuges has been a really enjoyable part for me.

Flylords: What does this research mean for conservation? Both in the Great Lakes region and nationally?

Matthias Bonzo: I think in both cases, it means more precise projects can get implemented and the money that is spent on conservation will go to the right areas instead of somebody putting money in on a project that isn’t actually going to affect an area where trout or other cold-water species are inhabiting. We can zero in on the spots that are the most important to these fish in these systems.

Jake Lemon: We’re always trying to use the best available tools. So when new tools become available, it behooves us to take advantage of them, right? Temperature is super important to what we do and we’ve done the traditional ways of monitoring temperature and that’s still important. But now there’s this new tool that allows us to get a much more fine-scale of information. We’re using it and trying to make it something that we can apply more broadly across the state and hopefully one day across the nation.

But as far as specifics go, when you have development come into areas and you remove those trees, then you’re basically reducing the ability of that groundwater discharge to happen. You’re either potentially warming water or reducing the amount that’s actually soaking into the aquifer. There’s been some work in Alaska where they’ve used this to identify important groundwater recharge zones for those discharges then prioritize those for long-term protection, just to keep those rivers cold for the long term. I’d love to see something like that here.

Stretch of the Muskegon River where data was being taken.

Flylords: Where can someone learn more about or contribute to the research that you guys are doing?

Jake Lemon: We have a science page where you find a lot of information about science work that we’re doing and ours is part of that program. I would recommend people get involved with their local chapter and work on the issues that are important in their local area. If people have expertise or resources that they’re willing to bring to the table, we’d certainly welcome it.

Flylords: Is there anything else you guys want to bring up or anyone you want to ‘shout out’?

Jake Lemon: The Forest Service. They’re a key partner in this and we’ve been working with them from the very beginning. They see the value in these data, and it’s been a partnership from the beginning on getting this thing off the ground so to speak.

A lot of this work is funded by Trout Unlimited donors as well and so without the donors that are supporting this work, it wouldn’t have happened. They’re directly helping to build a capacity within our organization that I think has a lot of potential to spread around the country. There’s so much interest in this work nationwide. We’ve been asked to go to Colorado, to Maine, and many other places. I’m already working with other staff for them to get built up and able to do this exact same thing.

A special thanks to Stealthcraft for allowing us to borrow the staff boat to get out for the day. Read the previous installment about how Trout Unlimited is working to remove the lower dam on the Snake River here. To learn more about how to become involved with your local Trout Unlimited chapter, click here.

All photos by Cobi Pellerito.

Boots on the Ground: Eric Crawford


Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.