Telling the story: UNL students relish opportunity to study AltEn contamination
ASHLAND — Underneath the seaweed-like coontail, wriggling in the mud is a bullfrog tadpole with a story to tell.
After hatching in early summer, the tadpole has spent the entirety of its short life in a farm pond 6 miles downstream from AltEn, a former biofuel plant where millions of pounds of pesticide-coated seeds were processed into ethanol.
Between 2015 and 2021, when the Nebraska Department of Environment and Energy ordered the facility south of Mead to shut down, wastewater tainted by agricultural chemicals routinely spilled into the surrounding countryside.
Channeled into a ditch on the east end of AltEn’s property, the pesticide-contaminated wastewater migrated through a University of Nebraska research farm and across a Nebraska National Guard training ground into the pond on Stan and Evelyn Keiser’s farmstead.
It’s in that collection point of a 6,000-acre watershed where scientists and student researchers hope to learn the tadpole’s story and what it can teach about the lingering effects of AltEn and its unusual method of ethanol production.
“The bullfrogs are an indicator species,” said Shabani Muller, a Ph.D. student in the School of Natural Resources at the University of Nebraska-Lincoln. “If the environment is contaminated with pesticides, we will see it in the tadpoles.”
As aquatic animals, the tadpole’s tissues will absorb chemicals present in their watery environment, including pesticides like clothianidin, thiamethoxam and imidacloprid found in high concentrations in waste at AltEn.
Two years ago, as research into the contamination stemming from AltEn got underway, UNL researchers discovered those neonicotinoids, several fungicides and other chemical compounds in all 10 tadpoles they gathered from the Keisers’ pond.
That was nearly nine months after the plant shut down — an indicator that pesticides were still present in the pond or continuing to move into it.
In the time since, the agricultural companies that formerly sent unplanted treated seeds to AltEn have undertaken efforts to stabilize the site, clean up millions of pounds of solid waste and treat millions of gallons of contaminated liquids.
Muller, a native of Tanzania studying ecology, said the pond remains an important place in helping researchers understand how long those chemicals remain in the environment, and how they may move through the ecosystem.
The tadpoles — and the story they can tell — are key to that understanding, Muller said.
“We are telling the world about the importance of the tadpoles,” he said.
Looking at the big picture
The massive study into the long-term effects wrought by AltEn — both to the residents living near the plant or downstream from it, as well as the environment and wildlife — has also provided a unique experience for students like Muller.
Fifteen students have been part of the multidisciplinary research effort conducted jointly by UNL, the University of Nebraska Medical Center and Creighton University, learning from and working alongside experts in biology, conservation and environmental science.
The study has been funded in part through a $1 million appropriation of American Rescue Plan Act funds from the Legislature in 2021. Spearheaded by Sen. Carol Blood of Bellevue, the research funding was attached to a bill (LB1068) from Sen. John Stinner of Gering designed to expand behavioral health internship and practicum opportunities in Nebraska.
UNMC has received the bulk of the funds — more than $537,000 — to establish a medical registry for Saunders County residents to track any health issues that may be tied to AltEn, study human exposure, survey those affected and administer the far-reaching project.
The rest of the $1 million appropriation — Blood initially sought $10 million, while the research team pegged the need at $7.8 million — has been split between UNL and Creighton for environmental sampling and analysis.
A total of $163,000 has been spent studying soil and surface and groundwater; $120,000 has been allocated for gathering birds, bullfrogs and other animals; and $109,000 has gone into researching AltEn’s effects on bees and plants, according to a summary from UNMC.
UNL students have gained hands-on experience in all of those areas. They’ve dug core samples, combed waterways for milkweed and other vegetation, scooped water from streams and ponds, hunted for red-winged blackbird eggs and maintained dozens of honey bee hives in Saunders County.
The multi-pronged approach through One Health, a program in UNL’s Institute of Agriculture and Natural Resources, is designed to allow students to see the links between various wildlife and the environment in which they live, according to Liz VanWormer, a veterinary epidemiologist at UNL.
“By taking all of these approaches, students will begin to layer the data in a way that helps them see the bigger picture,” VanWormer said.
Sometimes, in order to gain that perspective and begin seeing the connections between human, animal, plant and ecosystem health, students need to get their hands dirty.
Digging in the muck
On a warm afternoon in early November, Muller and Nikki Klosterman, a senior fisheries and wildlife major from Lincoln, are waist deep in the Keisers’ pond at either end of a sein net hunting bullfrog tadpoles.
A non-native species, bullfrogs were introduced into fish hatcheries across the Cornhusker state from Louisiana in the late 1930s and early 1940s by the Nebraska Game and Parks Commission, and quickly spread to other bodies of water where they continued to multiply.
Considered a culinary delicacy in the South and other places, bullfrog tadpoles are largely ignored by predators, meaning there likely are plenty of samples for researchers to grab.
At the direction of herpetologist Dennis Ferraro, a professor of practice at UNL, Muller and Klosterman pull the net taut, tilt it backward 45 degrees, and begin to advance toward the bank, scraping it just above the bottom.
If the conditions were ideal, the net would be pulled to shore and a handful of tadpoles — maybe more — could be plucked out of the muck and dropped into plastic containers.
But the muddy bottom means Muller and Klosterman spend just as much effort trying to keep their footing as they do pulling the net, giving the tadpoles an avenue of escape.
Several passes along the south bank of the Keisers’ pond turn up nothing, while others are successful, netting as many as three in a single haul.
“It’s really hard to understand the difficulty of wildlife sampling until you spend hours digging through the muck to find tadpoles,” VanWormer said.
Klosterman, who joined the project as a summer intern and quickly gained experience doing vegetation sampling and looking for bird nests, said she relishes the chance to do any kind of field work, despite the slow progress being made.
“You can sit in a class and learn, but until you actually get out there you never know what it’s like,” she said. “Every day is different depending on the conditions, but I’m really excited to do it because it’s such a huge part of the job.”
The experiences have helped her home in on what she hopes to do after graduating, she said. Instead of focusing on conservation efforts for mammals, Klosterman said she now wants to work with giant raptors — hawks and eagles.
“Who doesn’t want to work with bald eagles?” she said.
Muller, who hopes to continue conducting research and teaching after earning his doctorate, said the experiences through the AltEn study will help him design future studies, as well as pass on the techniques he has learned to others.
Building connections
With the mid-afternoon sun starting to sink in the west, the small research team retreats to the bank to count their bounty.
Ultimately, the trip to the Keiser pond resulted in eight tadpoles that, because of the time of year in which they were caught, will provide a good comparison to the samples collected two years ago.
VanWormer said that as the presence of pesticides has diminished in other areas that have been studied — surface water and in bee hives, for example, trends she attributes to the plant’s closure and the ongoing remediation efforts — she expects the tadpoles will reflect that, too.
“Optimistically, we hope to see lower levels here also,” she said.
In addition to looking for the presence of neonicotinoids, VanWormer said UNL is also planning to study how the pesticides change the tissues where they accumulate.
“Just by looking at them, you may not see any difference visible with your eyes, but looking through the different layers, we can see if they have an impact on tadpole development,” she explained.
It’s a story UNL hopes to share in the future in conjunction with the results gleaned from the interconnected research efforts that have been ongoing for several years.
And it’s a story students, whether they be Ph.D. candidates like Muller or undergraduates like Klosterman, will continue to help tell.
“I never really thought about how the pesticides can leach into the water and affect everything around it until I started doing this,” Klosterman said. “All of these ecosystems are connected.”
