Olorunsaye’s Research Sheds Light on Estuarine Water Quality

Tosin Clegg

Olasunkanmi Olorunsaye, a leading figure in estuarine hydrogeology, has made significant strides in understanding how water and nutrients cycle through estuaries—where rivers meet the sea.

In his latest research, obtained by ThisDay, Olorunsaye examines the movement of water and dissolved chemicals in these complex environments. His findings highlight how these interactions shape nutrient levels, water quality, and the overall health of coastal ecosystems.

A key focus of his work is the exchange between groundwater and surface water in estuaries. Olorunsaye stresses that understanding these exchanges is crucial for predicting their impact on marine ecosystems and managing water resources effectively. His ongoing studies delve into the various factors influencing these interactions and their effects on coastal water chemistry.

“This research looks at how tides, currents, and the density differences between seawater and freshwater drive the movement of water and nutrients across the sediment-water interface in estuaries,” Olorunsaye explained.

One pressing issue the research addresses is the influx of nutrients, particularly nitrogen from agricultural runoff, into estuarine waters. These nutrients are carried into the seabed by tides and currents, where they cycle back into the estuary. During this cycle, chemical reactions in the sediment can transform and reduce the nutrient levels. However, if these natural filtration processes are overwhelmed, it can lead to harmful algal blooms, affecting marine life and potentially closing beaches.

“These groundwater processes could have a global impact on coastal ocean chemistry,” he said. Despite previous studies on water and chemical exchanges in riverbeds and coastal oceans, Olorunsaye points out that there’s still much to learn about the flow of groundwater across the sediment-water interface in estuaries.

“In estuaries, tides move inland, currents shift directions, and rising sea levels make the hydrogeological environment increasingly complex,” he said. “Our goal is to better understand how groundwater flows and the chemical reactions occurring in aquifers beneath various types of estuaries. This will help us connect the dots between fluid exchanges below the sea and those across riverbeds.”

Olorunsaye’s findings could significantly improve water-quality forecasting, reducing risks from coastal pollutants. His research is expected to lead to more effective strategies for managing nutrient pollution and protecting coastal ecosystems. This has led to prestigious awards, including the GSA’s Graduate Student Research Award and the Outstanding Mention Award in Hydrogeology alongside being a part of several conferences globally.

Additionally, his work provides valuable insights into saltwater intrusion in coastal aquifers. These findings could inform better placement of pumping wells, improving water resource management, especially in coastal areas of Nigeria where access to clean water is critical. Many coastal communities rely on these aquifers, and sustainable management could directly benefit their water supply and livelihoods.

By deepening the understanding of estuarine hydrogeology, Olorunsaye’s research offers a promising path toward enhancing coastal water quality, resource management, and the sustainability of estuarine ecosystems, especially in vulnerable regions like Nigeria. His work is poised to help communities adapt to environmental challenges while safeguarding vital water resources.