Semester of Graduation
Summer 2026
Degree
Master of Science (MS)
Department
The Department of Environmental Sciences
Document Type
Thesis
Abstract
Inland fisheries contribute to Louisiana’s (LA) economy, yet are threatened by water-quality degradation. An important system for inland fisheries in LA is Lac des Allemands, which lacks comprehensive baseline studies regarding water quality, fisheries, and sources of pollution. This study integrates water quality monitoring, fish assemblage surveys, satellite-derived eutrophication indicators, land-cover change analysis, drainage channel analysis, and nutrient export modeling to assess ecological condition and management priorities in Lac des Allemands and the Upper Barataria Basin. Results demonstrate that the lake is persistently hypereutrophic, with elevated nitrogen and phosphorus concentrations, seasonal reductions in dissolved oxygen, and cyanobacteria concentrations exceeding the World Health Organization recreational-water threshold of 100,000 cells mL⁻¹. Dissolved oxygen was lowest in summer and showed a significant decreasing trend over time. Fish assemblage findings indicate that recreationally important species are present. However, seasonal low dissolved oxygen levels, cyanobacterial dominance, and the presence of tolerant species suggest potential ecological stress. The findings also demonstrate urban expansion (+2,934 ha) largely replacing cropland, while woody wetlands declined (−415 ha) over the study period. Nutrient-export hotspots are concentrated in developed and agricultural areas along levee margins. While wetlands throughout the basin have the potential to absorb these nutrients, extensive alteration to the hydrological connectivity may limit this ecosystem service. Together, these results provide baseline information on the Lac des Allemands system and highlight the need for watershed nutrient management and the restoration of hydrological connectivity.
Date
7-13-2026
Recommended Citation
Rahi, Taherunnesa, "LAND USE CHANGE, NUTRIENT EXPORT, AND WATER QUALITY DEGRADATION IN THE UPPER BARATARIA BASIN: AN INTEGRATED ASSESSMENT FOR FISHERIES MANAGEMENT IN LAC DES ALLEMANDS, LOUISIANA, USA" (2026). LSU Master's Theses. 6425.
https://repository.lsu.edu/gradschool_theses/6425
Committee Chair
De Jesus Crespo, Rebeca
LSU Acknowledgement
1
LSU Accessibility Acknowledgment
1