Science Research Mentoring Program

Earth Day 2025: Teens Investigate a Microplastic Time Machine 

[Yuki, a high school student with long brown hair is seated in front of shelves holding jars of fish specimens.]

YUKI (Science Research Mentorship Program student): Microplastics? It's kind of, like, in the name. 

[BRIGHT, BOUNCY, BUT OFF-KILTER MUSIC WITH AN URGENT RHTHYM]

[Singular pieces of microplastic flash by in a diversity of shapes and colors. Some are sharp, like broken pieces of glass, others bubbly and warped, or like long fibers.]

FREYA (Science Research Mentorship Program student): Microplastics are a form of pollution. 

[Freya, a high school student with glasses and long, dark hair is seated in front of shelves holding fish specimen jars.]

FREYA: They're kind of stuff that sheds off of normal plastic items.

[Various piles of microplastics flash by, again displaying a wide variety of colors, shapes, and textures.]

RYAN THONI (Curatorial Associate, Department of Ichthyology): They come from everywhere. 

[Ryan Thoni, a bearded man in a brown long-sleeved button down shirt, sits in his Museum office.]

THONI: They shed from our polyester clothing that we're wearing… 

[Low angle view of a truck driving on a road.]

FREYA: from tires…

[A variety of grocery store shelves, displaying products in plastic packaging.]

YUKI: the single plastics in, like, our food packaging, and stuff like that.

[A plastic water bottle floats in a stream. A plastic bag, tatty and twisted around a tree branch, hangs over the water.]]

MIA (Science Research Mentorship Program student): They're basically just pieces of plastic… 

[Mia, a high school student in a hooded sweatshirt sits at a desk. Behind her are shelves displaying jars of fish specimens.]

MIA: …that have broken down and become very, very small 

[Thoni speaks in his office.]

THONI: And it might seem like they're going away because we don't see them. But all that means is they're really getting down to the near molecular level. 

[On a monitor, we see the view from a microscope of fine tweezers picking at a tiny plastic fiber.]

THONI: Below five millimeters and it can go extremely small.

[A microscope image, labeled with a scale bar of 100 nanometers, displays a microplastic fiber.]

[Mia speaks to camera]

MIA: I was aware of microplastics and kind of their increasing harm to the environment, but I never really learned anything that in-depth about them.

[Mia and Thoni examine a microplastic fiber on the microscope monitor in a lab space.]

THONI: We don't know anything really about what microplastics are doing to us yet. So we're not here to scare us. 

[Thoni, Mia, and Yuki confer over data in a bright lab space with a large metal table.]

THONI: We're simply here to look at levels of microplastics, not make assumptions about what that means for our health or for the fishes that we're studying. 

[Thoni pulls up a seine net from a river. Dozens of fish swim inside.]

[LAUGHTER]

THONI: We're just out to get answers.

[AMNH logo animation]

[Thoni examines a small fish caught in the seine net.]

THONI: I am Ryan Thoni, the Curatorial Associate of Ichthyology at the American Museum of Natural History. 

[Thoni and the three students talk in the Ichthyology lab.]

THONI: I have three fantastic students—Mia, Freya and Yuki. In no particular order. They're all awesome. 

[Thoni and his students examine a large fish specimen in the Museum’s Ichthyology collection.]

THONI: I don't know what happened to high school students, but they became so much smarter than when I was there.

[Freya and Mia prep fish specimens in the Ichthyology lab.]

[On-screen text: SRMP - Science Research Mentorship Program]

FREYA: We're in the SRMP program, which stands for the Science Research Mentorship Program. 

[Mia speaks to camera.]

MIA: It's basically a program that allows high school students to work under a mentor on a research project. 

[Mia dissects a fish specimen and assembles laboratory equipment.]

MIA: And it gives you a really unique opportunity to learn about research in a more hands-on and in-depth way.

[Mia operates a microscope, while Thoni, Yuki, and Freya look on.]

MIA: So basically, we’re studying the microplastics in New York State fish since 1950. 

[Archival 1950s footage with a woman in a plastic raincoat opening a plastic umbrella.]

[GENTLE, DRONING MUSIC]

MIA: Because that's when plastics were kind of starting to get more produced.

[Underwater footage of a dozen fish being released from a net and swimming past the camera.]

THONI: Fish, particularly in freshwater systems because they tend to be enclosed, they're a real tangible indicator of the ecosystem that they're in.

[Hands pick up fish from a net and transfer them into a bucket.]

THONI: We're looking at levels of microplastics using both contemporary specimens… 

[Close-up of a fish in a jar with a Museum specimen label.]

THONI: …and going back in time using museum specimens. 

[Various views of a stream located right next to a busy roadside.]

THONI: Answer questions like, when did microplastics show up in New York State waterways, exploring levels of microplastic over time. 

[Camera moves through the Ichthyology lab as the team works at the microscope and prepares glassware.]

THONI: The hypothesis going into this is that plastic levels are going to be on the rise. 

[Mia speaks to camera.]

MIA: So, the first few weeks of the mentorship program, we kind of spent in the collection rooms… 

[Views of the Ichthyology collections space, which holds thousands of jars of fish specimens, and the students looking through the shelves.]

MIA: …looking through all the specimens, trying to determine which ones would kind of best represent the New York fish and also which ones were most common.

[Yuki speaks to camera.]

YUKI: We went on, like, a little, like, field trip to get our own specimens. 

[Still photographs of the three students outdoors, dressed in waist-high wading pants.]

[Three people in waders prepare a net in a river running immediately next to a busy roadway. Cars and trucks whiz by in the background.]

[On-screen text: Saw Mill River, New York]

THONI: We chose some sites that were near the city… 

[Close-up of a specimen label in a jar reading, “Sawmill River, 12 July 1979”.]

THONI: …and had been visited by previous researchers whose collections are in the museum. 

[Freya and Thoni, dressed in waders, seine the river for fish.]

FREYA: We took some big nets that we had to pull through the river ourselves. And just for a couple of hours, we sat in the river, dragging the nets through the water and picking out fish. We threw back any that were too big or too small.

THONI: Nice job, Freya!

FREYA: Holy cow.

[Thoni speaks to camera.]

THONI: It's important to collect fish from the same place because we study change in environments over time. 

[Thoni and the team pull up a seine net full of fish.]

THONI: So if you can go back to the same place that you went to 40 years ago and see, not only do you have the same species, but what's changed about them, it can answer questions like that.

[Thoni and Freya wade in the river, carrying the seine net.]

FREYA: We picked four fish species. And when we went to collect specimens ourselves, we managed to gather specimens from each of these four species. 

[Thoni pulls a large fish with a sucker-type mouth out of the net.]

THONI: That’s Catostomus commersonii.

[Mia speaks to camera.]

MIA: We chose these fish because they represent, like, the different trophic levels in the New York State environment.

[Thoni speaks to camera.]

THONI: So that would be, you know, from bottom feeders to middle- midline predators to apex predators.

[Freya displays a jar full of bottom-feeding fish.]

[On-screen text: Catostomus commersonii | white sucker]

FREYA: My species is the white sucker, Catostomus commersonii. It's a bottom feeder. 

[Close-up of a jar containing several fish specimens with large eyes and a spot on their side.]

THONI: And then you have sunfishes—so, bluegills, pumpkin seeds. They are in the genus Lepomis.

[Mia displays a bluegill specimen with forceps.]

[On-screen text: Lepomis macrochirus | bluegill]

MIA: This is the Lepomis macrochirus. It's really cool. 

[Close up of a single, small fish, about the size of a finger.]

[On-screen text: Etheostoma olmstedi | tessellated darter]

THONI: And we have another sort of bottom-oriented small predator, which is a darter, Etheostoma olmstedi. And then finally, we have the genus Esox.

[Yuki pulls out a pickerel specimen from a jar with forceps. She’s smiling.]

[On-screen text: Esox niger | chain pickerel]

YUKI: I'm doing pickerel, which are, like, the apex predators among our chosen specimens. They're like the top dog.

[Shelves of fish specimens from various decades. The students dissect fish in the Ichthyology lab]

MIA: Since we're taking from a wider range of species and trophic levels, it gives us better results.

[A small pickerel shakes a smaller fish in its mouth.]

THONI: Maybe we see some patterns. Maybe apex predators that eat everything below it are accumulating more of these plastics. 

[Several bottom-feeding suckers forage among stream rocks.]

THONI: Or maybe the bottom feeders, the suckers are actually accumulating more plastics in their system.

[Close-up of Yuki’s gloved hands cutting open a pickerel. She then looks at the microscope screen as she adjusts the magnification.]

FREYA: We're dissecting them, looking at the number of microplastics in their stomachs.

[Yuki pulls out a pickerel’s digestive system and puts it into a small foil cup.]

MIA: We first extract the digestive system. 

[Yuki carefully measures out a liquid into a lab beaker. She drops the digestive tract in the solution and puts a labelled foil cap on top.]

MIA: And then we prepare a solution. And we put the digestive system in the solution. And it sits for two days to a week. 

[Mia speaks to camera.]

MIA: It should be, if everything goes well, just a liquid. 

[Mia pours the solution through an assembly of lab glassware. She uses a handpump to force the liquid through a filter.]

MIA: And then we put it through a vacuum, which just kind of takes out all the water. 

[Close-up of a latex-gloved hand displaying a dish with filter paper, divided by pencil lines into four quadrants. Hands place the dish under a microscope lens.]

FREYA: We're looking at what remains under that microscope, looking at different quadrants on the filter paper.

[Mia operates the microscope, scanning the filter paper for pieces of plastic. Close-up of the monitor shows a blue plastic fiber.]

MIA: And we basically just count every single individual microplastic piece that we can see.

[Yuki speaks to camera.]

YUKI: We're primarily looking at, like, colorful, kind of like square-ish kind of shapes… 

[Stills of various microplastic pieces on filter paper—bright red jagged flakes to dull brown chips to bright blue fibers.]

YUKI: …like a neon blue or like a neon orange but then we would also look and see if it's solid or not. 

[Using fine tweezers, Mia manipulates a tangled bundle of microplastic fibers.]

YUKI: So, that would, like, be an indication of a microplastic.

[Microscope shots zooming closer in to the knot of tangled plastic fibers.]

[Close-up of specimen jar label reading “Catostomus commersoni, Sawmill R.” Jars holding specimens from various decades.]

THONI: We use Museum specimens so that we not only have a snapshot of what's going on today, but we can see trends over time.

[Yuki stands in front of shelves with jars of fish specimens. She points out jars as she’s talking.]

YUKI: So, like, I've labeled this, based on the decades. These are the ones that we caught. And then these are like the older, like, actual museum specimens. 

[Thoni speaks to camera.]

THONI: And we’ve gone back through the ‘90s, and the ‘80s, and the ‘70s. And we are finding plastics all the way as far back as the ‘70s so far. But it sure seems like there's a lot more in our contemporary specimens.

[Mia looks at computer screen, displaying a graph of data results.] 

FREYA: You can see the slope of the line and the R²-

[Close-up of the computer screen graph. The title reads “Microplastics Count Trends in Genus Lepomis Over the Last Century.” A line averaging plot points slopes steeply to the right, indicating a growth trend in microplastic occurrence from the 1950s to the 2020s.] 

THONI: Look at that!

[The team stands behind Mia looking at the data.]

FREYA: It’s really a representation of the increasing microplastics in fish over these decades that we’re studying.

[Wide shot of Freya wading through the middle of the stream, wearing tall waders and dragging a small net.]

[GENTLE BUT THOUGHTFUL SYNTH MUSIC]

FREYA: The fact that there's microplastics in the fish means that there's definitely even more just in the water. It's really important to have that measurement of past decades, because otherwise these numbers become incredibly arbitrary.

[The team dissects fish and reviews data in the Ichthyology lab.]

THONI: We're not the first people ever to go back in time and look at microplastic levels. 

[Repeated shots from behind the heads of the three students, as they look through the microscope again and again.]

THONI: But science works in repetition. 

[Thoni speaks to camera.]

THONI: And, if somebody else does it in Illinois or California or another country… 

[Students enter data on a laptop and via a hand-written log sheet.]

THONI: …the more numbers we have, the more precise our science can become.

[Mia dissects a fish specimen.]

THONI: Right now we're just looking at the G.I. tract of these fishes. 

[Thoni speaks to camera.]

THONI: So what if we start looking at other organs like liver, kidney, heart, things like that? 

[Thoni directs the team where to place nets in the Saw Mill River.]

THONI: Certainly there's more health questions involved there than just indicators of plastics in the environment. 

[The team pulls the seine through the river. Fish flap their tails inside the net.]

MIA: In general, the fish have just kind of confirmed what I've always thought… 

[Scraps of plastic bags, a broken plastic bucket, and a plastic bottle float near the river’s edges.] 

MIA: …in that we don't know that much yet and it's really hard to come to any conclusions about how exactly harmful they are. 

[The team pulls fish from the net. Close up of a large fish.]

MIA: But it's still really awakening to see it in person. It's kind of like, you see it, you finally believe it. 

[Credits roll.]