Document Type
Thesis
Date of Award
2022
Degree Name
Master of Science (MS)
Department
Biology
First Advisor
Jeff S Wesner
Abstract
Blue Suckers are a declining long lived catostomid, native to the large rivers and tributaries of the central United States. Currently in decline throughout their range due to anthropogenic impacts such as river channelization and dam construction, there are few stable Blue Sucker populations remaining. This study sought to describe population demographics of a stable population of Blue Suckers located in the unchannelized reach of the Missouri River below Gavins Point Dam. Year class strength, growth, and natural mortality was estimated based on aging data collected from lapillus otoliths. Previous research was conflicting as to what aging structure, pectoral fin rays or lapillus otoliths, provide the most reliable ageing estimates for Blue Suckers. Direct comparisons in this study showed fin rays underestimate otoliths and differences in estimates increased as otolith age increased. As many other studies used other aging structures for population demographics, it is likely those estimates are inaccurate and should be reevaluated with otoliths. Additionally, this study sought to describe movements of Blue Suckers in a large tributary, the James River, through two years. Results showed variable movement by season with most movement occurring in the Spring when Blue Suckers migrate to spawn. Movement was also correlated to discharge. In a low water year, there was little upstream movement and fish retreated into the Missouri River. In a high water year, there was significant upstream movement into the James River. Fish passage over a large rock dam over two years indicated dams impact Blue Sucker movements at high and low water levels. This study has shown Blue Suckers use tributaries when water levels allow, likely as alternative spawning habitat. Also, Blue Suckers would likely benefit from dam removals in these tributaries. Results of this study provide comparable demographic and movement data of a stable population of Blue Suckers.
Subject Categories
Biology
Keywords
Acoustic Telemetry, Aging, Blue Sucker, Population Dynamics, Telemetry
Number of Pages
79
Publisher
University of South Dakota
Recommended Citation
Carlson, Tanner Leigh, "POPULATION DYNAMICS AND SEASONAL MOVEMENTS OF BLUE SUCKERS (CYCLEPTUS ELONGATUS) IN THE JAMES RIVER, SOUTH DAKOTA" (2022). Dissertations and Theses. 306.
https://red.library.usd.edu/diss-thesis/306
