The Great Lakes may be home to some fish that were alive around the turn of the century.
The 16th century.
Findings by a team of researchers from Michigan State University, Michigan Technological University, and Michigan’s and Wisconsin’s respective departments of natural resources suggest that female lake sturgeon can live up to 427 years, while males can live up to 279 years.
Scientists have long believed the species, an ancient group of fish from the Lower Jurassic about 200 million years ago, topped out at around 150 years. They are known as living fossils because their ancestors date to the time dinosaurs roamed, according to phys.org.
The findings, published in April in the Journal of Fish Biology, would make lake sturgeon one of the longest-lived species of vertebrates on the planet, rivaling the Greenland shark, which can live up to 400 years, according to National Geographic. They also provide new insights into lake sturgeon longevity that could help inform conservation strategies, population management and harvest regulations.
How the study was conducted
The researchers used 44 years of existing data on five genetically distinct sturgeon populations found in five geographically separate habitats in the Great Lakes: Black Lake, Michigan; Sturgeon River, Michigan; Menominee River on the Michigan-Wisconsin border; St. Clair River on the Michigan-Ontario border; and Lake Winnebago, Wisconsin.
After studying more than 1,200 fish, the team calculated each fish’s average annual growth and charted it by location and sex. They then used those models to estimate the ages of female sturgeon that measured 180 centimeters long, or nearly 6 feet, and males measuring 160 centimeters long, or a little over 5 feet, which are roughly average lengths for adults of most sturgeon species.
Traditional methods of calculating sturgeon’s age rely on estimates based on survival in captivity or counting growth rings, or annuli, in structures such as fin spines. But the researchers said this method becomes less reliable as sturgeon age and growth slows, potentially underestimating true longevity.
In the 1960s, an expert concluded that a 208-pound sturgeon caught in Ontario near the Minnesota border was 152 years old, according to the Michigan Department of Natural Resources. Some scientists have since questioned whether that was an extreme case.
But the 2026 study found that the 152-year estimate was likely an underestimation, and that the fish was closer to middle age than old age.
Using their alternative approach, the researchers estimated that the male sturgeon sampled for the study ranged in age from 90-279 years, while females ranged from 99-427 years old.
The researchers stressed that the ages are statistical estimates rather than verified ages of any individual fish. Instead of assigning an age to any one sturgeon, they used decades of growth data from tagged fish to estimate how long it would take a typical male or female in each population to reach a standardized size.
The fish with the oldest estimated ages came from Michigan’s Black River population, where slow annual growth, due perhaps to relative food scarcity, translated into the greatest estimated longevity, the researchers wrote.
By contrast, fish from the St. Clair River and Lake Winnebago, which grew more quickly, reached the same benchmark lengths at much younger estimated ages. The findings suggested that longevity can vary dramatically among populations, even within the same species.
Michigan anglers expressed a mix of disbelief and awe regarding the study.
“I’m skeptical,” said Scott Assenmacher, an angler from Dearborn. He suggested sturgeon could live hundreds of years, but only under “perfect conditions.”
New Boston angler John Wrixon said he doesn’t doubt the study’s findings. As a species, sturgeon are at least 150 million years old, according to the U.S. Fish and Wildlife Service. So, Wrixon figured, humans still know very little about their lifespans.
“… In terms of sturgeon life…, research is still young,” Wrixon said. “It’s not like some other species where we have had them in captivity and documented for X amount of years.”
Brenda McCall Armchambo of Black Lake, a past president of the Black Lake Chapter of Sturgeon for Tomorrow, is curious how the data will affect efforts to preserve the ancient species.
“It will be interesting to see how this new research is evaluated and incorporated into future fisheries management and conservation,” Armchambo said. “Science is always evolving, and studies like this help us better understand these incredible fish.”
Ramifications on conservation
The study’s authors noted that although an understanding of species’ longevity is key to effectively managing their populations, the lifespan of fish is generally not well-documented, especially among long-lived species.
The findings carry important implications for conservation, the researchers wrote.
Lake sturgeon do not reach sexual maturity until about age 15 for males and 24 for females, according to the assumptions used in the study, meaning the fish spend decades growing before they can reproduce.
If they also survive for centuries, adult fish represent an especially valuable part of the population because they have many opportunities to spawn over their lifetimes, the team wrote.
The authors said their findings support conservative harvest regulations and underscore the importance of protecting adult lake sturgeon.
Sturgeon fishing is already highly restricted in Michigan. The state limits harvest to one fish per angler per year, while some waters — including Black Lake — also have strict overall harvest quotas to protect local populations. Last year, the limit at Black Lake was six fish in total, and the entire season lasted all of 48 minutes.
The researchers suggested that the ages of other long-lived sturgeon species may be underestimated by traditional aging methods, and could benefit from similar long-term capture-mark-recapture studies.
Other species of sturgeon known for their long lifespans include white sturgeon and green sturgeon, both found along North America’s Pacific Coast; Atlantic sturgeon, found along the Atlantic Coast of North America; and beluga sturgeon, found in the Caspian and Black Sea basins.
mreinhart@detroitnews.com
This article originally appeared on The Detroit News: Sturgeon, ‘living fossils,’ may be older than thought — way older
Reporting by Max Reinhart, The Detroit News / The Detroit News
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By Max Reinhart, The Detroit News | USA TODAY Network
