Population Size Of Pallid Sturgeon In The Lower Missouri River Near Missouri City, MO

Listed as endangered in 1990, pallid sturgeon (Scaphirhynchus albus) is one of the rarest fish species in the Missouri River.  The population size of pallid sturgeon has been estimated for a reach of the Missouri River near Plattsmouth, NE.  However, the population size is not currently known for the rest of the lower Missouri River, an area with highly variable catch rates of pallid sturgeon.  In this study, we used the robust design within Program MARK to estimate the population size of pallid sturgeon within a 43.3 river kilometer (rkm) reach near Missouri City, MO using mark-recapture data of fish sampled during broodstock collection efforts in 2011 to 2013.  The annual population estimate of wild pallid sturgeon in this study area varied from 0.6 to 0.9 fish/rkm; whereas, the population estimates of known hatchery-origin pallid sturgeon varied from 5.5 to 10.2 fish/rkm.  These population estimates are less than the estimates near Plattsmouth, NE.