Embedded Files
From field observations to biogeochemical processes
From field observations to biogeochemical processes
High-frequency monitoring captures the daily rhythms of freshwater ecosystems. Sensors record dissolved oxygen, temperature, pH, and underwater light at intervals of minutes rather than months, which resolves the diel cycles that conventional sampling averages away. Water chemistry, stable isotopes, and quantitative models then help interpret the processes behind those patterns, separating biological activity from carbonate equilibrium and physical exchange with the atmosphere. Fieldwork runs across all four seasons, because a process that dominates in July may be undetectable in January.
Ph.D. Projects
Ph.D. Projects
My dissertation at Vanderbilt examines how natural biogeochemical cycles and artificial light at night shape carbon and nutrient dynamics in freshwater systems. Lakes and ponds are not static reservoirs. Over the course of a single day their oxygen, pH, and carbon chemistry can swing further than they do across an entire season, driven by photosynthesis during daylight and respiration after dark. Those short-term rhythms carry the signature of the biological and geochemical processes that govern how a water body stores, transforms, and releases carbon and nutrients, yet most monitoring programs sample too infrequently to see them. My work combines intensive field campaigns, continuous sensor deployment, analytical geochemistry, and quantitative modeling to resolve those rhythms and interpret the processes behind them. Two field sites anchor the research: Stephens Lake, an oligotrophic headwater lake in Middle Tennessee, and the Tennessee State University Farm Pond, a shallow eutrophic system in Nashville. Studying both allows the same methods to be applied across contrasting trophic states, which is where the mechanisms become visible.
Freshwater carbon cycling, stable isotopes & lake metabolism
Freshwater carbon cycling, stable isotopes & lake metabolism
How do biological activity and carbonate chemistry jointly shape daily and seasonal carbon cycling? At Stephens Lake, an oligotrophic headwater lake in Middle Tennessee, 48-hour campaigns and high-frequency sensors resolve changes that infrequent sampling can miss. My first project examines how the biogeochemistry of a small freshwater lake changes over both daily and seasonal timescales. I conduct intensive diel sampling at Stephens Lake across different seasons to track changes in dissolved oxygen, carbon chemistry, stable isotopes, and other water-quality parameters over 24-hour cycles. I combine these measurements with lake metabolism modeling to estimate gross primary production, ecosystem respiration, and net ecosystem production. The broader goal is to understand how processes such as photosynthesis, respiration, atmospheric exchange, and seasonal environmental conditions control carbon cycling and water chemistry in shallow freshwater systems.
Artificial light at night & aquatic ecosystem metabolism
Artificial light at night & aquatic ecosystem metabolism
My second project investigates how artificial light at night, or ALAN, affects the functioning of freshwater ecosystems. I am conducting a field experiment in a eutrophic pond where different sections are exposed to red and blue nighttime light while another section serves as a control. By continuously monitoring dissolved oxygen, light, temperature, and other environmental variables, I can determine whether nighttime illumination alters photosynthesis, respiration, and overall ecosystem metabolism. I am also examining biological responses such as phytoplankton and benthic algal activity. The goal is to understand whether an increasingly common form of human disturbance, nighttime light pollution, can change fundamental biogeochemical and ecological processes in aquatic systems.
Nutrient & phosphorus biogeochemistry in freshwater systems
Nutrient & phosphorus biogeochemistry in freshwater systems
My third project focuses on nutrient cycling, particularly phosphorus, in freshwater environments with very different nutrient conditions. I am comparing the relatively oligotrophic Stephens Lake system with the more eutrophic TSU Farm Pond and its associated wetlands. I collect surface water, porewater, and sediment-related samples across seasons and measure different forms of phosphorus and nitrogen, along with elements such as calcium, iron, manganese, and aluminum that can influence phosphorus mobility. I also use geochemical modeling to evaluate mineral saturation and potential controls on phosphorus retention or release. The overall goal is to understand why nutrients behave differently across contrasting freshwater systems and how geochemical and biological processes regulate nutrient availability and eutrophication.
Previous Research
Previous Research
Before beginning my Ph.D. at Vanderbilt, my research addressed two distinct problems in aquatic geochemistry. My M.S. work at Auburn University investigated groundwater hydrogeochemistry in coastal Bangladesh, where salinity intrusion and geogenic contamination threaten drinking and irrigation water supplies. Earlier, during my M.S. at the University of Dhaka, I studied the abundance and spatial distribution of microplastics along Bangladesh's coastline. Across both projects I combined extensive field sampling with geochemical and statistical analysis to understand how natural and anthropogenic processes shape water and sediment quality in vulnerable coastal systems, work that continues today through ongoing publications and collaborations.
Coastal groundwater and hydrogeology
Coastal groundwater and hydrogeology
My M.S. thesis at Auburn University examined the hydrochemical characteristics and quality of groundwater in Hatiya Island, a low-lying coastal region in southern Bangladesh where salinity intrusion and geogenic trace elements threaten both drinking and irrigation water supplies. I sampled groundwater across the island and analyzed major ion chemistry and water quality indices to trace the hydrochemical evolution of the aquifer and identify the processes governing its composition. Combining these results with multivariate statistical analysis, I assessed the suitability of the groundwater for domestic and agricultural use and identified the areas most vulnerable to saline intrusion. The work contributed to a broader understanding of how coastal aquifers in low-lying deltaic settings respond to natural salinity sources and land-use pressure, and it has continued through collaborative studies on groundwater contamination and salinity risk elsewhere in coastal Bangladesh.
Environmental contaminants and microplastics
Environmental contaminants and microplastics
My first M.S. research, completed at the University of Dhaka, characterized the abundance and spatial distribution of microplastics along the coastal regions of Cox's Bazar and St. Martin's Island, Bangladesh. I combined field sampling of beach and nearshore sediments with laboratory analysis of particle size, shape, and polymer type, then used GIS to map contamination patterns across the coastline. This was among the earlier characterizations of microplastic pollution in this part of the Bay of Bengal, and it opened into a line of research I continue to pursue, including studies on microplastic risk indexing, polymer-specific hazard profiling, and the use of machine learning to predict contamination in coastal sediments.
Page updated
Google Sites
Report abuse