Atlantic sturgeon have a broad distribution along the east coast of North America. When 332 specimens from 11 river systems were genetically analyzed a pronounced latitudinal cline in the number of composite mtDNA haplotypes was discovered. Haplotypic diversity increased from north (St. Lawrence River, New Brunswick) to south (Satilla River, Georgia) and from previously glaciated and subsequently recolonized systems to the portion of their range which was never glaciated. The greater genetic diversity shown by southern populations is most likely a continuity of these populations through the Pleistocene and as a result of their higher mutation rates associated with their shorter generation times. This study found stock structure among the southern populations and evidence of at least seven genetic stocks. The researchers conclude that management efforts to augment natural reproduction with hatchery production should use broodstock from the rivers in which the offspring are to be stocked.