Spatio-Temporal Pattern of Nutrient Dynamics in the South Texas Coastal Watershed

Author

Mohammad Sadman Alam, The University of Texas Rio Grande Valley

Date of Award

5-2025

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Ocean, Coastal, and Earth Sciences

First Advisor

Jongsun Kim

Second Advisor

Myung Hwangbo

Third Advisor

Tian Y. Dong

Abstract

Eutrophication threatens aquatic ecosystems by altering productivity through excessive nutrient inputs. In some systems, primary productivity is limited by nitrogen (N), phosphorus (P), or both, based on the N:P ratio defined by the "Redfield" ratio. South Texas, facing rapid urban growth and industrialization, is at risk of higher nutrient loads, but research on nutrient dynamics in this region is limited. This study investigates nutrient variations in the freshwater (FW) abandoned distributaries of the Rio Grande and hypersaline saltwater (SW) systems. Results showed a significant decrease in dissolved inorganic nitrogen (DIN) and an increase in dissolved inorganic phosphorus (DIP), shifting the FW from P-limited to N-limited in summer (N:P = 0.5:1). Conversely, the SW remained P-limited (N:P > 16:1) in both seasons. These findings highlight the impact of anthropogenic activities and biogeochemical processes on nutrient limitations in different aquatic environments.

Comments

Copyright 2025 Mohammad Sadman Alam. https://proquest.com/docview/3240628830

Recommended Citation

Alam, M. S. (2025). Spatio-Temporal Pattern of Nutrient Dynamics in the South Texas Coastal Watershed [Master's thesis, The University of Texas Rio Grande Valley]. ScholarWorks @ UTRGV. https://scholarworks.utrgv.edu/etd/1727