Assessment of pallid sturgeon relative condition in the upper channelized Missouri River

ABSTRACTDuring the spring 2015 sampling efforts on the Missouri River, several adult pallid sturgeon (Scaphirhynchus albus) were captured in a visually emaciated condition. As pallid sturgeon recovery efforts continue throughout the Missouri River, this may negatively impact the local population and hamper recovery. Therefore, the objectives were to (1) assess the annual variation in pallid sturgeon condition, (2) determine how condition varies amongst gender and reproductive status and if condition affects fecundity, (3) determine the annual proportion of reproductive female pallid sturgeon, and (4) test several hypothesized factors which may contribute to variations in pallid sturgeon condition. Overall, the relative condition of pallid sturgeon has significantly declined over the past 12 years, except for the large adult-sized fish (> 840 mm fork length). Pallid sturgeon condition began to decline in 2013 then rapidly declined in 2014 and even more in 2015. The mean annual pallid sturgeon condition rea...