Genetic Tagging and Parental Genotype Reconstruction for Recovering Lower Missouri River Pallid Sturgeon

A conservation propagation program for endangered Pallid Sturgeon (Scaphirhynchus albus) in the lower Missouri River was implemented to augment stocks and reduce the likelihood of local extinction.  While hatchery-origin progeny are currently stocked exclusively into the management unit (MU) from which their parents were collected, past practices allowed stocking of offspring of upper Missouri River broodstock into the lower Missouri River across current MUs.  Some of these offspring are now mature and are being recaptured as part of the broodstock collection program.  While all stocked fish were physically tagged, tag loss has been considerable and many of the hatchery-origin fish are unmarked.  Use of hatchery-reared offspring of upper Missouri River broodstock is potentially detrimental to pallid sturgeon recovery because it increases the likelihood of inbreeding, outbreeding, and domestication.  We are using genetic tagging to identify hatchery-origin pallid sturgeon by matching them to known parental crosses.  Where parental tissue samples are not available we are reconstructing unsampled parental genotypes using tissue samples from offspring of known crosses maintained in a captive broodstock program.  Once we have identified as many hatchery-origin fish as possible we will use a landscape genetics approach to better understand natural (pre-augmentation) stock structure of pallid sturgeon and to assess the impacts of artificial propagation and stocking.