Date of Award

Summer 6-21-2023

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)

School

Biological, Environmental, and Earth Sciences

Committee Chair

Brian Kreiser

Committee Chair School

Biological, Environmental, and Earth Sciences

Committee Member 2

Jake Schaefer

Committee Member 2 School

Biological, Environmental, and Earth Sciences

Committee Member 3

Adam Kaeser

Abstract

Gulf sturgeon (Acipenser oxyicnhus desotoi) are a large, anadromous fish belonging to an ancient lineage that diverged as early as 400 MYA. Overfishing for meat and caviar during the early 1900’s reduced their range and abundance and continued habitat destruction and mortality have limited their ability to recover, leading to their listing under the Endangered Species Act. This study uses genetic techniques to determine the effective number of breeders for multiple spawning groups of Gulf sturgeon in river systems across their range to set a baseline for tracking reproductive success of the species. Accompanying genetic information relevant to the management and ecology of the species is also reported. Results of genetic population structure analyses suggested the most prominent genetic divide across the range occurs between the eastern and western rivers. These analyses also identified three genetically distinct fall spawning groups within the Suwannee, Choctawhatchee, and Apalachicola Rivers. Average annual effective number of breeders estimates were similar in the Pearl River, Apalachicola spring, Choctawhatchee 1, and both Suwannee groups, but lower in the Apalachicola fall. Total effective number of breeders ranged from high to low as follows: Suwannee spring, Suwannee fall, Apalachicola spring, Pearl, Apalachicola fall. Measures of genetic diversity and relatedness were generally similar across groups, but the Suwannee fall and Apalachicola fall cohorts tended to possess slightly lower diversity and higher relatedness. The results of this study present pertinent information relating to the management of Gulf sturgeon populations, particularly regarding the existence and condition of fall spawning groups.

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Biology Commons

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