Pallid Sturgeon Population Assessment and Monitoring on the Missouri River

 The U.S. Army Corps of Engineers (Corps) under the requirements of the 2000 Missouri River Biological Opinion (Opinion) has multiple responsibilities related to the endangered pallid sturgeon (Scaphirhynchus albus).  Identified within the Opinion are elements specifically related to the recovery needs of pallid sturgeon that include implementing a pallid sturgeon population assessment and monitoring program.  The monitoring plan is designed to assess abundance, population structure, distribution, and habitat use of wild and hatchery-reared (stocked) pallid sturgeon.  A suite of native Missouri River fish species has also been identified and incorporated into the program to provide a more timely and comprehensive assessment of the overall changes in the ecosystem, which includes management actions implemented to benefit pallid sturgeon, rather than assessing a single, long-lived endangered species.  The program has been fully implemented during the last 6 years throughout the Missouri River basin with high priority segments of the Missouri River main stem sampled from Fort Peck Dam in Montana to its confluence with the Mississippi River in Missouri.  Since the program’s inception, an adaptive approach has been used to improve the sample design and to refine protocols.  An independent scientific review, statistical power analysis, and synthesis reporting have also been utilized to guide program direction.  Future program refinements include: evaluating the power to detect abundance trends in target fish populations; developing Bayesian approaches for modeling the relative abundance of target fish species; evaluating gear redundancy; and improving information transfer through a geospatially-referenced electronic database management system.