Bettoli, P.W., M. Casto-Yerty, G.D. Scholten, and E.J. Heist. 2009. Bycatch of the endangered pallid sturgeon (Scaphirhynchus albus) in a commerical fishery for shovelnose sturgeon (S. platyorynchus). Journal of Applied Ichthyology. 25:1-4.
We quantified the bycatch of pallid sturgeon Scaphirhynchus albus in Tennessee’s shovelnose sturgeon (S. platorynchus) fishery by accompanying commercial fishers and monitoring their catch on five dates in spring 2007. Fishers were free to keep or discard any sturgeon they collected in their gillnets and trotlines and we were afforded the opportunity to collect meristic and morphometric data and tissue samples from discarded and harvested specimens. Fishers removed 327 live sturgeon from their gear in our presence, of which 93 were harvested; we also obtained the carcasses of 20 sturgeon that a fisher harvested out of our sight while we were on the water with another fisher. Two of the 113 harvested sturgeon were confirmed pallid sturgeon based on microsatellite DNA analyses. Additionally, fishers gave us five, live pallid sturgeon that they removed from their gear. If the incidental harvest rate of pallid sturgeon (1.8% of all sturgeon harvested) was similar in the previous two commercial seasons, at least 169 adult pallid sturgeon were harvested by commercial fishers in the Tennessee waters of the Mississippi River in 2005-2007. If fishers altered their behavior because of our presence (i.e., if they were more conservative in what they harvested), the pallid sturgeon take was probably higher when they fished unaccompanied by observers. While retrieving a gill net set the day before, a fisher we were accompanying retrieved a gillnet lost two days earlier. That ghost net caught 53 sturgeon; one fish was harvested and most fish were dead in the ghost net, including one confirmed pallid sturgeon.