WATER QUALITY EXAMINATION OF ALTERNATIVE POND-BASED PRODUCTION SYSTEMS FOR REARING LARGEMOUTH BASS (Micropterus nigricans)

Author

Asyeh Sohrabifar, Southern Illinois University CarbondaleFollow

Date of Award

12-1-2025

Degree Name

Master of Science

Department

Civil Engineering

First Advisor

Fakhraei, Habibollah

Abstract

Aquaculture's rapid expansion emphasizes the critical importance of water quality for fish health and productivity. Innovative systems like Split Ponds (SP) and Pond-side Tanks (TK) have been used for cultivating Largemouth Bass (LMB) while addressing challenges such as cannibalism and feed fluctuations. These systems also enhance water treatment through the nitrogen cycle, a fundamental process in aquatic ecosystems. Nitrification plays a vital role in this cycle by converting harmful unionized ammonia (NH₃), which can disrupt fish cell membranes, into the relatively less toxic nitrite and nitrate. This study investigates the impact of water circulation on key water quality parameters and in enabling the nitrogen cycle, improving nitrification to effectively transform toxic ammonia into nitrate and alleviating ammonia-related toxicity in the water, thereby promoting the health and productivity of fish.Over a multi-month grow-out period, ammonia, nitrite, nitrate, pH, dissolved oxygen (DO), temperature, conductivity, oxidation-reduction potential (ORP), chlorophyll, and total organic carbon (TOC) were monitored weekly for three replicate treatments for both SP and TK as well as a Full Pond (FP) system. In concurrence, LMB populations within treatments as well as feed amount were monitored to better understand nutrient dynamics within treatments. Among the three systems SP, TK and FP, the SP system demonstrated the most balanced and acceptable environmental conditions conducive to rearing Yong of Year (YOY) LMB. Although both TK and SP demonstrated superior nitrification than FP, the SP system offered more desirable, stable DO concentrations for LMB. The lower temperature profile maintained in the SP compared to both FP and TK may have offered a buffer to improve stability in other parameters, including DO. The results support the viability of SP systems for intensive LMB culture. This research contributes to a limited but growing body of knowledge on water quality in engineered pond systems, especially regarding LMB culture in SP and TK configurations, which remain underexplored in aquaculture literature. The results underscore the value of partial recirculation and compartmentalization in enhancing system sustainability and provide a scientific foundation for optimizing nutrient management in pond-based aquaculture.