Sturgeon age is read from cross-sections of a pectoral fin ray, which lays down annual growth zones. Applied to lake sturgeon, the method has produced ages beyond 100 years for females in northern waters, with males typically shorter-lived. Females may first spawn at around twenty to twenty-five years and then return only every four to nine years.
That schedule made the species vulnerable when Great Lakes fisheries in the nineteenth and early twentieth centuries took sturgeon in bulk, first as a nuisance and later for flesh and caviar. Populations crashed and have recovered slowly, aided now by strict harvest limits and by removing barriers to spawning rivers. The species is globally listed as Least Concern but is protected or threatened in many individual jurisdictions.
Fin-ray ageing is known to underestimate age in very old fish, so the true maximum lifespan for the species may be greater than the published records suggest.