Date of Award

12-10-2022

Document Type

Thesis

Degree Name

Master of Science in Coastal Marine and Wetland Studies

Department

Coastal and Marine Systems Science

College

College of Science

First Advisor

Derek P. Crane

Second Advisor

Erin J. Burge

Third Advisor

Christopher E. Hill

Additional Advisors

Ellen Waldrop

Abstract

Information on abundance and body growth are important for understanding the status and health of populations, and this information can be used to guide and monitor conservation and recovery efforts for species of conservation concern. The Atlantic Sturgeon (Acipenser oxyrinchus oxyrinchus) is an anadromous fish native to the Atlantic coast of the United States and Canada. Due to overfishing and habitat degradation, population levels declined, and Atlantic Sturgeon were placed on the Endangered Species list in 2012. Although there is substantial research on adult Atlantic Sturgeon, knowledge about their early life history is lacking. The objective of this study were to estimate annual abundance of juvenile Atlantic Sturgeon in the Edisto River, SC, over a 25-year period. I also estimated growth and growth rates of juveniles, what environmental factors were related to growth and growth rate, and if growth differed between seasonal cohorts. Drifted gill nets were used to sample juvenile Atlantic Sturgeon in the Edisto River, SC from 1994–2019. I estimated the number of juveniles in the river during May through September of each year based on daily and monthly encounter histories using the POPAN version of the Jolly-Seber open population model. I calculated average growth per day and growing degree days for each individual and a suite of linear models were used to determine what environmental factors (mean temperature, growing degree days [GDD], and discharge) and biological factors (total length at initial capture and seasonal cohort) were related to growth rate and overall growth between captures. Juvenile (≤1050 mm) abundance averaged 845 individuals (range = 333–1,343, 95% CI = 644–1,046) based on the average of daily and monthly encounter history population estimates. Growth rate was weakly related to the environmental and biological variables investigated (most likely model R2 = 0.32). Absolute growth between captures was related to initial TL at capture, mean temperature, discharge, GDD, seasonal cohort, and the interactions between GDD and mean temperature, and GDD and initial total length (most likely model R2 = 0.89). The results of this study provide the first long-term abundance estimates for juvenile Atlantic Sturgeon in the southeastern United States and increase our understanding of juvenile Atlantic Sturgeon biology.

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