Genetic Management Plan for the Endangered Pallid Sturgeon (Scaphirynchus albus) Captive Broodstock Maintained at Gavin's Point National Fish Hatchery

Author

Melody Saltzgiver, Southern Illinois University CarbondaleFollow

Date of Award

1-1-2009

Degree Name

Master of Science

Department

Zoology

First Advisor

Heist, Edward

Abstract

Pallid sturgeon (Scaphirhynchus albus) is a native North American fish that was listed as a federally endangered species in 1990 due to failure in spawning and recruitment, perhaps as a result of human modifications to their habitat. The upper Missouri River basin pallid sturgeon have been shown to be genetically distinct from other pallid sturgeon. Since there has been no natural recruitment in the upper Missouri River for several decades, perpetuation of this genetically distinct unit is reliant on propagation using remaining wild fish as broodstock. The expense associated with acquiring unique individuals from the remaining wild broodstock is causing wild collection to become a less viable option each year. It has been proposed that rearing progeny of wild broodstock fish in a hatchery setting as captive broodstock may be feasible alternative to wild collections. The genetic risks associated with the creation of a captive broodstock need to be investigated and a captive management plan needs to be developed prior to the implementation of a captive broodstock program. The relatedness values and the effective population size for the wild caught founders were determined by genotyping wild upper Missouri River pallid sturgeon at 16 previously developed microsatellite loci. The founding wild broodstock were shown to encompass an ample amount of genetic variation and a sufficiently large effective population size. The broodstock currently housed as Gavin's Point National Fish Hatchery can be exclusively used for the propagation of pallid sturgeon to be stocked in the upper Missouri River with the caveat that descendents from each wild fish will be spawned in the future and that the reproductive variance of the broodstock be controlled to maximize Ne and thus reduce inbreeding.