On a quiet stretch of the Maumee River in northwest Ohio, 120 tiny lake sturgeon—each no longer than a pencil—were slipped into the water between 2018 and 2021, carrying with them the hopes of a decades-long restoration dream. These fish, part of Ohio’s first-ever reintroduction of lake sturgeon, were raised in two different ways: some in the controlled tanks of the Genoa National Fish Hatchery in Wisconsin, others in a streamside facility at the Toledo Zoo that pulsed with real Maumee River water. Scientists wondered: would the fish raised on local water be more likely to remember the river, to one day return and spawn? A new study, co-authored by Dr. William Hintz of The University of Toledo and published in the Canadian Journal of Fisheries and Aquatic Sciences, delivers a surprising answer—initially, at least, it doesn’t seem to matter.
Lake sturgeon once thrived across the Great Lakes, living up to a century and growing longer than a person is tall. But by the 20th century, overfishing, pollution, and dammed rivers had all but erased them from Ohio waters. The reintroduction program, launched in 2018 by a coalition including the Ohio Department of Natural Resources, U.S. Fish and Wildlife Service, U.S. Geological Survey, The University of Toledo, Michigan State University, and the Toledo Zoo, aims to bring them back—one juvenile at a time. The ultimate goal is clear: establish a self-sustaining population of 1,500 spawning adults in the Maumee.
To track the young sturgeon, researchers implanted acoustic tags in 120 fish across three release years and monitored them via underwater receivers. The results showed that 79% of the 94 detected fish left the Maumee for Lake Erie within just 47 days, with none showing a strong preference for staying behind based on their rearing method. Whether hatched in Wisconsin or nurtured on Maumee water at the Toledo Zoo, the sturgeon behaved similarly—venturing into the western basin of Lake Erie and lingering along the south shore, near the Lake Erie islands. On average, they spent between three and 47 days in the river, then 54 to 207 days in the lake.
While the early movements show no significant difference, the real test lies ahead. Lake sturgeon don’t mature until they’re at least 10 to 20 years old. “While we found no difference between rearing strategies at this age, the real test of our work will come when these fish are old enough to spawn,” said Dr. Hintz. The team recommends expanding the acoustic receiver network, adding upstream stocking sites, and potentially using Maumee River water in hatcheries if future data shows too many fish straying from their home river. For now, the journey of these ancient fish is just beginning—and the Maumee waits, hopeful, for their return.