Date of Award
8-16-2022
Document Type
Dissertation
Degree Name
Environmental Sciences, Ph.D.
First Advisor
Jennifer Bouldin
Committee Members
Brook Fluker; Hubert Stroud; John Harris; Mohamed Milad
Call Number
LD 251 .A566d 2022 A89
Abstract
Freshwater is an important, finite, commodity necessary for nearly all facets of human life. Due to its vast usage, a large portion of freshwater has become impaired, impacting water quality. Worldwide, pollution from rivers and streams are causing eutrophication in marine environments into which they flow, negatively affecting aquatic life. The hypoxic zone in the Gulf of Mexico has reached record size in the last decade with agricultural activity within the Mississippi River Basin, including the Cache River Watershed of northeast Arkansas, contributing to the cause. Over 70% of the Cache River Watershed is used for agriculture and the upper half is channelized, which contributes to the sediment, nutrients, and lead (Pb) impairments in the watershed. In this dissertation, 14 locations (12 tributary and two main channel) of the Cache River with varying levels of agricultural intensity were monitored weekly for sediment, nutrients, and Pb from October 2017 to September 2020. Agricultural intensities were determined using United States Geological Survey’s National Land Cover Database satellite imagery and consisted of four categories: low, low moderate, moderate high, and high. Additionally, Pb content was measured in three fishes (Gambusia affinis, Lepomis cyanellus, and L. macrochirus) collected during community composition fish surveys conducted in 2019 and 2020. Suspended solids and total Pb levels increased with increasing agricultural land use while low moderate intensity had the greatest nutrient levels. Despite being detectable in fishes, Pb content was below levels of concern for human consumption and was greatest in the lower intensity sites, with the exception of L. macrochirus. Overall, 42 fish species were sampled and identified with moderate high intensity sites having the most species and low intensity the greatest diversity and evenness. This study provides a spatial and temporal evaluation of the Cache River Watershed to indicate problematic subwatersheds that warrant the implementation of mitigation strategies. Data can then serve as a baseline for the effectiveness of these mitigation practices. Additionally, the fish survey can be used as a reference for future ichthyological studies within the highly altered upper portion of the watershed and for comparison in the unaltered, lower Cache River Watershed.
Rights Management
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Atwell, Amelia K., "Assessment Of Water Quality, Fish Diversity, and Lead (Pb) in the Agriculturally Dominated Upper Cache River Watershed, Arkansas" (2022). Student Theses and Dissertations. 252.
https://arch.astate.edu/all-etd/252
