Multiple abundance estimates are available for different life stages of Atlantic sturgeon in various rivers. Abundance estimates require that no fish are entering or leaving the population (emigration, immigration, birth, or death) when the number of fish are counted. Generally, these conditions are present during a spawning runs of adults or when a groups of juveniles are still too young to leave their natal river. Because we can only know individual sturgeon when we capture them, all of these estimates have a relatively wide range. Recent abundance estimates include:
Recent work in the St. John River, Canada, has identified the largest population of Atlantic sturgeon on the East Coast. Recent abundance estimates found 18,000 to 21,000 adult sturgeon between 2013 and 2015. Scientists in Canada have estimated the mean annual adult abundance to be 20,798 individuals. A commercial fishery on the St. John River removes up to 350 adult sturgeon per year.
In 1995, sampling crews on the Hudson River estimated that there were 9,500 juvenile Atlantic sturgeon in the estuary. Since 4,900 of these were stocked hatchery-raised fish, about 4,600 fish were thought to be of wild origin.
The commercial fishery for Atlantic sturgeon on the Hudson River was closed in 1998. Using data from the commercial fishery between 1980 and 1992, at the time the fishery was closed, there were an estimated 870 adults (600 males and 270 females).
Mark recapture sampling in the Delaware River in 2014 resulted in 181 juvenile sturgeon being marked and four of those were recaptured. The resulting estimate of juvenile abundance that year was 3,656 individuals.
The York River is one of the more recent Atlantic sturgeon spawning populations discovered. In 2013, the first year spawning was confirmed, an estimated 75 adult individuals participated in that year’s spawning run. Since that time, annual abundance estimates have been calculated, ranging from 75 per year to about 225 per year with a total adult population of approximately 300 individuals.
In the Pee Dee River, side scan sonar imaging was used to estimate approximately 1,823 to 1,944 adult or sub-adult Atlantic sturgeon in the river during the three day sampling period. Because shortnose sturgeon can grow slightly larger than one meter in length, it is possible that some of these individuals were large shortnose sturgeon rather than sub-adult Atlantic sturgeon.
The Altamaha River supports one of the most robust Atlantic sturgeon populations in the Southeast, The number of juvenile sturgeon produced by these spawning runs ranges from 1,000 to 2,000 individuals occupying the river each year, 87 percent of which are 1 to 2 years of age. The population appears to be stable or possibly increasing.