February 11, 2026
American paddlefish, a long-lived and long-snouted fish species, can be found throughout the Mississippi River Basin. They are popular with anglers, some of whom have been fishing the same spots for decades. There is also a large commercial market for paddlefish, especially their roe.
American paddlefish, an ancient fish like their cousins, the sturgeon, are the last surviving paddlefish in the world. Their closest relative, the Chinese paddlefish, was declared extinct in 2020 after impacts from habitat changes, pollution, and over-harvest. American paddlefish face many of these same pressures.
To protect paddlefish and maximize benefits to the people and economies that rely on them, natural resource managers want to make the best possible management decisions. To do that, they need the best possible science.
“The Illinois Department of Natural Resources (DNR) recognized a gap in knowledge related to the management of paddlefish at a national level, so they took action to address it,” said Dr. Cory Suski, a professor in the Department of Natural Resources and Environmental Sciences at the University of Illinois at Urbana-Champaign. He worked with the Illinois DNR to design a study to illuminate elements of basic physiology, such as temperature tolerances, and answer questions such as: how do paddlefish differ across their wide range and how do they interact with anglers?
What Warmer Temperatures Mean for Paddlefish
Shasta Kamara, a University of Illinois doctoral student, was brought on board to lead the project with support from the Midwest Climate Adaptation Science Center (CASC).
“This project is trying to make sure that paddlefish management is the most successful it can be,” Kamara explained. “For a really popular sport and commercially harvested fish, it's important to know that our assumptions are correct.”
For example, when an angler releases a paddlefish that is undersized, they tend to assume that the fish goes back into the water and survives just fine. But that’s not always the case. Kamara hoped to understand these angler interactions, and related variables like temperature, through this research.
Her findings, recently published in The Journal of Thermal Biology, indicate that paddlefish angled and released in warmer water temperatures (over 17.5 degrees Celsius) require a longer recovery period than fish in cooler waters. Her research also indicates that paddlefish may have limited adaptation capacity or the ability to cope with climate change impacts, which include warmer waters.
“Paddlefish are harvested across a broad range of dates – you might be able to harvest from October 1 until May 31. The Mississippi River can change temperature significantly across that range, all the way from zero to 22 degrees Celsius,” Kamara said. “As our summers get warmer, what was once a good harvest window may no longer align with what’s best for the paddlefish. Natural resource managers will need to consider this as they determine harvest dates.”
Collaboration Across State Lines
While the project began in response to specific needs at the Illinois DNR, Kamara’s research has required close collaboration with scientists and management professionals from state and federal agencies, other universities, and private companies across the Mississippi River Basin. Importantly, those partnerships crossed state and agency boundaries. Traditionally, management happens on a state-by-state basis, but paddlefish are migratory and their movement across state lines can sometimes render state-led strategies less effective making interstate collaboration more crucial.
“It was really cool to talk with managers in different regions and learn how our project could help. We also heard about aspects that we hadn’t yet thought about and work that has been done in their area that might be complementary to our studies,” Kamara said.
“Oftentimes, researchers are very good at completing studies and generating data but ensuring that stakeholders obtain and use information is underdeveloped,” Suski said. “Our partnership with the Illinois DNR meant that we not only had access to outstanding resources to answer a question that was a priority for managers, but we also had a direct connection to people that manage resources around the region that showed a genuine interest in the work and the outcomes. This synergy between researchers and managers has been rewarding and has helped ensure successful outcomes and outputs from the project.”
Continuing to Fill Knowledge Gaps
Kamara’s research will next focus on exploring physiological differences in paddlefish across their wide range. From the northern to southern ends of their range, she explains, there is major variation in how paddlefish go about their lives.
“They have kind of a live fast, die young strategy in the south, where they reach maturity sooner, spawn as frequently as they can, then die at about 30 years old. In the north, they reach maturity later and have longer intervals between spawning. In Montana, they’ll live up to about 60 years old.”
Using paddlefish from the north end of their range – South Dakota and Montana – and the south – Louisiana and Oklahoma – she’s exploring variations in temperature tolerance, swim performance in different temperatures, metabolics, egg nutrition and other metrics that might result in different adaptive capacity between the two stocks.
Paddlefish are a relatively data-poor species, which makes this work especially important. By assessing their physiological and life history traits, researchers can determine their adaptive capacity and inform management strategies to support them as climate change affects different parts of their range.
“What I love most about this work is the collaboration – trying to make sure that we don't operate within bubbles anymore. It was a unique opportunity to be able to connect a lot of scientists across the paddlefish range. It's been great, and I hope to take that forward in my next projects and throughout my career,” Kamara said.
Read the publication in The Journal of Thermal Biology.