The old red brick building situated near the Larsen Tractor Museum, and innocuously named Service Building on University of Nebraska-Lincoln maps, was empty when Jamilynn Poletto was handed the keys.
The assistant professor at the School of Natural Resources wasn’t daunted. Instead, the fish physiologist rolled up her sleeves, and along with her two graduate students Zach Horstman and Alex Engel, got to work building a laboratory dedicated to studying the physiology of fish.
“We built this from the ground up,” she said. “There was literally nothing in here.”
Now inside are 12 gleaming 350-gallon circular tanks, their shiny silver insulation wrap glimmering under the fluorescent lights. Hoses hang from the ceiling, pumping air into the temperature-controlled systems, and pipes connect each row of four tanks to the others and to water and bacteria filters. The set-up allows each row of tanks to operate on its own water recirculation system, meaning the lab can isolate tanks or rows of tanks should the need arise to quarantine disease.
Generators hum at the front of the rows, and elevated walkways allow Poletto, Horstman and Engel to reach into the tanks, allows them to conduct their research.
If it seems complex, it’s even more so than immediately meets the eye.
A UV light sterilizes the water, and a custom-made carbon filter eliminates the chloramine and chlorine in Lincoln’s water supply, so the water in each tank is as pure as possible before research projects begin.
“Fish physiology isn’t just about knowing fish or statistics or experimental design,” Poletto said. “You can’t just be good at handling fish.
“It’s also about knowing how to plumb; having a mechanical knowledge of how to fix pumps; of have electrical know-how. It’s knowing the difference between a GFCI and non-GFCI outlet. And how to use power tools.”
Poletto’ s lab is so unique, she couldn’t affordably commission someone to build it. And so she climbed inside empty tanks and up on ladders, and with her team, put the laboratory together piece by piece over the course of six months. It’s been dubbed The Fish Conservation Behavior and Physiology Lab.
Dealing with multiple variables at one time
“When it comes to fish physiology, we’re very good a studying growth, reproduction and swimming capability,” Poletto said. “But we can’t keep studying individual stressors — fish are never dealing with one thing at a time.”
The lab setting, unlike natural ones, allows Poletto and her crew to have control over which variables they are looking at when tackling scientific questions.
Take one research project utilizing the 12 standard fishing tanks in the lab, home to dozens of fathead minnows. The past body of scientific research has shown fish species can only tolerate hot water temperatures to a certain threshold. But no one has looked at how thermal tolerance is affected once pesticide contaminants are in water.
“We hypothesize that an increased contaminant load will drop fish’s temperature tolerance because they are experiencing too many stressors at the same time,” Poletto said. “It’s like when you are sick, you can’t handle as much.”
On the other end of the lab, 20 to 40 flathead catfish from nearby aquatic systems circle inside each of the large gurgling tanks. Here Poletto and her students are studying how water temperature may affect how quickly fish digest their food. They suspect the flathead are getting an early-growth boost, allowing them to out-compete channel catfish in the same water bodies.
“We know fish require different amounts of food at different temperatures,” Poletto said, “but we want to predict the flathead catfish’s growth rate, model the population growth, and then compare it to channel catfish models.”
In the end, the lab gives Poletto and the University of Nebraska-Lincoln the ability to link the physiology of the fish with water management decisions, potentially saving endangered species and stabilizing ecosystems.
“We’ve never been able to test the questions we've had about native fishes directly,” Poletto said. “Now we can, and I anticipate what we discover will help in our management and our state’s management of them.”
See more
See a Facebook album highlighting the The Fish Conservation Behavior and Physiology Lab.
Shawna Richter-Ryerson, Natural Resources