The nation’s largest assessment of mercury contamination started as a project between scientists, teachers, and students at Acadia National Park. How has the help of more than 6,000 citizen scientists improved our understanding of mercury pollution across the US?

Schoodic Institute at Acadia National Park: www. schoodicinstitute.org

The Dragonfly Mercury Project: https://www.nps.gov/subjects/citizenscience/dragonfly-mercury-project.htm

Schoodic Notes: https://schoodicnotes.blog/

[Soundscape from Bass Harbor Head Light including buoy bells, waves lapping, and birdsong]

Olivia: Sea to Trees is brought to you by Schoodic Institute at Acadia National Park. I’m Olivia Milloway.

Olivia: What do a wild seaweed harvester, a middle-schooler with a love for centipedes, and a nature writer have in common? All three carry the honorary title of citizen scientist.

Margie: I'm Margie Patlak, and what else you do you need me to say? [Laughs] The weather here is perfect, and it's always a beautiful day in Maine.

Olivia: That was Margie, the nature writer. She spent the majority of her career writing about biomedical research, but has lately turned her attention toward the natural world, more specifically, the insects around her home in Corea, Maine. Margie is a citizen scientist because she helps record information that can be used to reach a greater understanding of a scientific question. The tool she uses is iNaturalist, a user-sourced global database of biodiversity, to identify insects she finds in her yard and wants to write about. In turn, the photographs she uploads are available for researchers to analyze, tracking where certain species show up across the globe.

Margie: It's like a win-win situation, because I’m going out and taking pictures and submitting it to iNaturalist so I get to know what it is and do my own research, but the scientists get to know that that insect is around and it helps them with their research.

Olivia: Margie first learned about iNaturalist at a Schoodic Institute citizen science training a few years ago.

Margie: I’m not the most digitally savvy person, but because I was able to get such good instruction in the workshop and we were able to practice it, I got it under my belt, and, you know, it’s with me all the time. I mean, I’m always trying to document and figure out what it is I’m seeing out in nature.

Olivia: You’re listening to Sea to Trees, a podcast that tells the stories of the science happening in and around Acadia from the rocky shoreline to the evergreen forests to the granite mountaintops. In this first season of the show, we’re exploring the ever-growing field of citizen science and how it can help answer questions about our changing world. In this first episode, we’ll learn more about the practice of citizen science here in Acadia National Park.

Abe: Citizen science is science that involves the public at some stage of the process, and that could be any part of the scientific process from the asking of questions to the collecting of data, to the analyzing or interpreting the data.

Olivia: That was Abe Miller-Rushing, the science coordinator for Acadia National Park. We met on Thompson Island, which, on that day, was especially buggy. Abe says that volunteers play an important role in the park's understanding of natural and cultural resources.

Abe: Citizen science is in fact the main way we know about birds in Acadia National Park, and in fact most national parks is my guess, that even our inventory and monitoring of birds in Acadia is done through citizen science–so volunteers going out and monitoring birds during the breeding season.

Olivia: Abe used the phrase inventory and monitoring, with inventory meaning the process of documenting the range of natural resources in Acadia, and monitoring to denote paying attention to how these resources are changing through time. Inventory and monitoring is a part of the National Park Service's responsibility, and it’s not just birds that citizen scientists are helping to document.

Abe: And it turns out that most of what we know about how the environment, how plants and animals are responding to climate change is from citizen science in the first place. A lot of what we understand about how the timing of the seasons is changing is from citizen science, people just noting when birds were arriving or when plants were flowering in their gardens, or in the woods on walks. And so citizen science has told us a lot about how the environment is changing, and we need to continue that going forward.

Olivia: In his doctoral research, Abe used the journals of Henry David Thoreau to show how the climate around Walden Pond had changed over the last century and a half. But besides their contributions to understanding how the biological timing of seasons is changing–what scientists like Abe call phenology–similar historical journals dating back to the 1800s have helped Schoodic Institute researchers understand how species are changing in Acadia. More on that in episode two. Personal records have also been crucial to documenting sea level rise in Acadia, including where Abe and I met for this interview.

Abe: So, right now we are on Thompson Island, which is near the head of Mount Desert Island where most of Acadia National Park is, and Thompson is a part of Acadia. This has actually been a really important place for citizen science and to document the impacts of climate change to the park. We had one volunteer in the park who, on his own, was documenting how Thompson Island has been eroding and how most of the firepits and picnic areas that were originally planned in this picnic area part of the park have eroded and are now in Frenchman Bay rather than on the island.

Olivia: This volunteer citizen scientist, Steve Perrin, contributed to many projects in Acadia, including a watershed map. For over a decade, he tracked erosion and sea level rise at Thompson Island, comparing the current state of the shoreline to historical photographs.

Abe: This erosion is continuing as a result of climate change, and really will likely continue going forward and is one of the visible ways that climate change is affecting the park and the places that people enjoy.

Olivia: The coastal areas around Acadia are also home to clams, worms, and other marine resources that sustain the livelihoods of commercial harvesters.

Abe: We’re surrounded by mudflats that are currently underwater but at low tide they’re exposed and this becomes a really important place for clamming and marine worm harvesting. Right now we have a lot of seagulls hanging out in the grass and the picnic area around us.

Olivia: Clam and marine worm harvesters, too, are contributing their knowledge to collaborative efforts to protect and restore intertidal areas in the park.

Olivia: Citizen scientists can help contribute to research in many ways, whether it’s through developing questions, collecting data, or analyzing that data. In the examples Abe brought up–monitoring breeding birds, blooming wildflowers, and sea level rise–contributions of citizen scientists have helped park staff cue into larger trends, providing the opportunity for them to consider specific follow-up studies or management strategies. Hannah Webber, Schoodic Institute’s Marine Ecology Director, has leveraged the help of citizen scientists in this way to study the reproductive cycle of sea stars.

Hannah: So in 2020, a friend of mine reached out and said, “Hey I'm seeing all these sea stars, it seems like we’re having a boom this year.” And I said, “Hey, wow, maybe we’re seeing a boom here too,” and we said, “Let’s create a citizen science call to action.”

Olivia: This friend was Heather Richard, who is now a graduate student at the University of Maine.

Hannah: I think we called it “Call to Five Arms,” it was quick, it was less than a month in 2020, we said just go out in this time period, let us know where you’re seeing sea stars and how many, and people just sent us pictures. It was awesome. I just got off the phone with someone who was like, “I’m picking up this study of the boom bust cycle of sea stars up and down the coast of Maine because of your project, because you generated all this knowledge about, about this particular sea star boom.” And that is not myself or my co-creator of that project, that’s somebody else who just has gotten some funding and is picking up and running with it. They wouldn’t have been able to do that without citizen science.

Olivia: One note on terminology–the term “citizen science” doesn’t mean that you need to have any particular citizenship status to participate; it’s meant to be inclusive rather than limiting.

Abe: We definitely don’t want the terminology to get in the way of who gets included. You can be any age to do citizen science, I’ve done citizen science where kindergarteners use popsicle sticks to label dandelions in their schoolyard and monitor those.

Olivia: Actually, students and retirees are the folks who most often participate in citizen science projects here in Acadia National Park. In addition to producing useful data about the park, citizen science is a powerful opportunity for engaging the public with the scientific process.

Abe: It’s not some big mysterious thing that only super duper experts can do, it’s something that all of us can participate in. It’s asking and answering questions.

Olivia: Supporting science, and making that science accessible to park visitors is a large part of Schoodic Institute’s work as one of seventeen Research Learning Centers in national parks across the country.

Abe: Schoodic Institute supports all of the science that happens at Acadia, citizen science or otherwise. A big function that Schoodic Institute plays here in Acadia and throughout the National Park Service is to help us test different ways of doing citizen science, identify the ways that work best, both for the science and the educational outcomes for the participants, and then to transfer and do that citizen science elsewhere in the national parks.

Olivia: A prime example of Schoodic Institute’s role of experimenting with different ways of doing citizen science is the Dragonfly Mercury Project, a citizen science project that’s now at more than 140 national parks whose precursor was developed here in Acadia.

Hannah: The Dragonfly Mercury Project, or DMP is a nationwide effort of the National Parks Service, US Geological Survey, Appalachian Mountain Club, Dartmouth College, and a host of other partners to use dragonfly larvae as a methylmercury biosentinel.

Olivia: Let’s break that last part down–first, methylmercury. Nowadays, mercury is widely known to be toxic for humans and the environment. But, it used to be used widely in agriculture, industry, and even household products. It wasn’t until 2009 that the international community reached an agreement to control mercury pollution, and mercury continues to be emitted by coal-fired power plants today. Methylmercury has a different chemical structure to pure elemental mercury–that silvery stuff that’s liquid at room temperature– making it easily dissolved in both fresh and saltwater and readily available to be taken up from the environment by fish and other aquatic species. Next, what’s a biosentinel?

Hannah: So this is a living organism that can sort of act as a bellwether, a marker of how much of any particular pollutant or toxin you’re interested in looking at. So really, just something that’s alive, bio, and sentinel, you know, sort of a lookout.

Olivia: For this project, dragonfly larvae are used as methylmercury biosentinels, or these living indicators of mercury pollution. The dragonfly larvae collected by citizen scientists are shipped to a United States Geological Survey Lab where they are analyzed to understand patterns of mercury pollution across a wide landscape. But how did we get to a project that’s involved more than 6,000 volunteers at over 140 national parks across the country? Before she became Schoodic Institute’s Marine Ecology Director, Hannah worked on the precursor to the Dragonfly Mercury Project, which was called the Acadia Learning Mercury Project at the time. This initiative brought researchers together with teachers and students to answer specific questions about mercury pollution.

Hannah: The project started here at Schoodic Institute with a researcher from the University Maine who was really instrumental, was the driving force behind starting Dragonfly Mercury Project, and that’s Sarah Nelson. who was at the time at the University of Maine and is now at Appalachian Mountain Club as the Director of Research there. And, Sarah worked with Bill Zoellick, who is emeritus here now, and engaged high school students in collecting samples of soil or leaf litter or organisms to analyze them for mercury to understand how mercury was moving through the environment.

Olivia: Hannah was a facilitator of sorts, calling herself the “glue person” of the Acadia Learning Mercury Project. She helped the scientists, teachers, and students work together to reach their own goals through this collaborative partnership. As a part of the program, students from different schools had the opportunity to share their work with each other, which helped Sarah come to a realization.

Hannah: There were some students who were presenting to each other one day and one of them said, “Why is it that your invertebrates have more mercury than ours?” and Sarah Nelson was listening, an attentive, amazing, incredible, still is, partner on this project, and recognized that the school with invertebrate samples coming from water bodies that were above wetlands were lower in mercury than students with invertebrates coming from water bodies that were below wetlands. And so, she had an amazing and incredible “aha” moment of what if aquatic macroinvertebrates could be biosentinels for methylmercury and of how mercury moves about a landscape. And then, it was a process of trying to figure out which macroinvertebrates would be best to use for biosentinels.

Olivia: Aquatic macroinvertebrate is a term that refers to any organism living underwater without a backbone, like worms, snails, or insect larvae, that can be seen without the help of a microscope. Dragonflies, along with caddisflies, beetles, and other insects have an aquatic larval stage. This project helped show that dragonfly larvae are an ideal methylmercury biosentinel.

Hannah: They’re long-lived, they stay in the same water body, they are predators, so they will take up mercury from their prey, and they’re ubiquitous.

Olivia: Dragonfly larvae are predators–they eat other aquatic macroinvertebrates and even small fish. Like other heavy metal toxins, mercury accumulates as it moves up the food chain from prey to predator. That’s why you’ve probably seen advisories to limit consumption of fish at the top of the food chain, like tuna or swordfish, or not to eat fish out of certain freshwater bodies.

Sarah: What we're to do with biosentinels is really, I think of it as lighting up a map; places that have a relatively high risk for mercury contamination, and relatively low. It was a bit of a eureka moment to realize that we could use dragonflies to tell us something about the spatial pattern of mercury in different streams, lakes, wetlands, around New England, and the project expanded from there.

Olivia: That was Sarah Nelson, who was watching the student presentations that day and connected the dots. The Acadia Learning Mercury Project was a resounding success–Sarah got much-needed data on mercury pollution, and refined her project design through insights from students. Teachers got an educational opportunity to engage their students with real science, and students participated in meaningful work.

Hannah: The Dragonfly Mercury Project, often that project is collecting dragonfly larvae but there's a whole exploration of what are in these ponds and wetlands for biodiversity writ large, not just the dragonfly larvae. Maybe that’s not data that’s important to you but they are to your participant, and allowing that space for it to not just be single-mindedly about your project really kind of opens the doors as well. Citizen scientists are the most amazing people, they want to contribute, they also want to learn, they want to grow themselves but their needs and motivations have to be met for there to be good citizen science.

Olivia: As the Acadia Learning Mercury Project continued to evolve and gain new partner organizations, its outgrowth spread from Maine to Vermont to New Hampshire, ultimately becoming the Dragonfly Mercury Project that is still running today. Made possible by the samples collected by citizen scientists, a 2020 study analyzed mercury concentrations in 100 National Park Service Units across the country. The study showed that dragonfly larvae could be used to estimate mercury contamination risk to people and wildlife. While dragonfly mercury concentrations varied widely, Acadia had the second highest recorded mercury level of the more than 450 sites in the study.

Sarah: Acadia tended to fall sort of in the moderate to high impairment risk, along with much of, really, the Northeast and New England, which isn’t entirely a surprise. We’ve had pollution from emissions sources in the air and the prevailing wind directions really carry that pollution across the country, and have deposited it a lot in Acadia the Northeast. I will say Mercury is also a global pollutant, so what happens around the globe affects us, but not a surprise that the Northeast tends to be a little bit higher.

Olivia: The Dragonfly Mercury Project is now the nation’s largest assessment of mercury contamination and environmental risk, and Sarah said it’s helped establish a baseline of mercury contamination data at public lands across the country.

Sarah: We now have baseline data for all of these national parks. I think over 140 parks at this point have participated. So, most of these places really didn’t have any, or very much mercury data before this project. Some have fish data, which USGS has also worked on, but it’s kind of keeping the mercury issue at the forefront, because it still is an issue in many places, there are fish consumption advisories for people, concerns about wildlife, and of course in parks we want to keep that front and center.

Hannah: There have been thousands of citizen scientists involved with this project over its lifetime who come not knowing necessarily about dragonfly larvae, the dragonfly life cycle, macroinvertebrates writ large in water bodies, about mercury or methylmercury. They leave having contributed samples to this effort, and also with a knowledge that there are ways to study the world that they can contribute to and that they can be, are, will be, a part of. So, I think that Dragonfly Mercury Project really meets the standard of engaging and building knowledge and awareness in the citizen scientist while also meeting the other goal of high quality rigorously vetted data.

Olivia: The Dragonfly Mercury Project in all its successes is just one example of how data collected by citizen scientists can be instrumental to the Park Service’s understanding of our changing environment.

Abe: There are a bunch of reasons why citizen science is important to Acadia National Park, and to the National Park Service more broadly. With climate change, and other environmental changes, conditions are changing very fast and we need more information and more science than we can collect with just our staff or just academic researchers alone.

Olivia: Understanding more about how the environment is changing could allow park scientists and managers to better protect natural and cultural resources in our rapidly changing climate. And, bringing the public into the scientific process has far-reaching implications.

Hannah: Anyone can be a scientist, science is for everyone, and that’s just a critically important message for us to share with people. You can do science, we need your data, everything that we study is something that’s in the commons, and therefore it’s something that we should all be paying attention to. Don’t leave it to just the scientists, it’s something for everybody, and so it is dreadfully important to us to engage people in science through citizen science.

Olivia: National Parks are supposed to be for everybody, but that hasn’t always been the case and not everyone feels welcome in parks. Creating ways to engage more diverse communities in citizen science projects that matter to them is a priority at Acadia now, and into the future.

Abe: I would say that citizen science is going to be an essential component of helping the National Park Service continue to do its mission in the future, and that in Acadia, and with the Schoodic Institute, we are helping to understand how we can best do citizen science to help achieve the Park Service’s mission, and help keep these places special for future generations and help give people incredible experiences doing science. Help train the next generation of scientists and stewards.

Olivia: Join us next episode to learn more about a citizen science tool that has been used in every country across the globe, and fits in your pocket: iNaturalist.

Mikayla: Thank you for listening to Sea to Trees, a podcast from Schoodic Institute at Acadia National Park. Acadia National Park is on traditional lands of the Wabanaki, People of the Dawn. This show was made by Olivia Milloway, the Cathy and Jim Gero Acadia Early Career Fellow in Science Communication. Catherine Schmitt is our senior editor. Additional editorial and production support was provided by Mikayla Gullace, Maya Pelletier, and Patrick Kark. Our music was written by Eric Green, performed with Ryan Curless and Stu Mahan and recorded at North Blood Studios in Damariscotta, Maine. The cover art was created by Sarah Luchini. Laura Sebastenelli of Schoodic Notes recorded the soundscape at Bass Harbor Head Light Station heard at the beginning of the episode. Special thanks this episode to Margie Patlak, Abe Miller-Rushing, Hannah Webber, and Sarah Nelson for sharing their expertise with us, and to the more than 6,000 citizen scientists who have volunteered their time to the Dragonfly Mercury Project. As a nonprofit partner of the National Park Service, Schoodic Institute inspires science, learning, and community for a changing world. To learn more, visit schoodicinstitute.org.