Award: OCE-1756788

The ongoing decrease in seawater pH because of uptake of anthropogenic carbon dioxide (CO2) from the atmosphere is known as ocean acidification, which can be enhanced by respiration in water column and seafloor sediments.  This research showed that in the Northern Gulf of Mexico (NGoM) hypoxic zone, the seabed plays an important role in the acidification of bottom ocean water. In this study we used field observations and numerical models to understand how the seabed can affect bottom water acidification over the NGoM hypoxic zone. We found that during fair weather periods, the sediment biogeochemical processes contribute significantly to acidification of the bottom water. When the ocean condition is dynamic such as after the passage of storm, the contribution of the seabed to bottom water acidification is enhanced. The finding has profound implications for similar coastal systems where eutrophication-induced bottom ocean acidification is likely more severe than previously thought. However further studies are needed to understand the persistence of such bottom water pH drop following a storm event and the role of alkalinity generation and fluxes from sediments counteracting such pH drop.

This project trained two graduate students and involved two undergraduate students in undergraduate research related to chemical oceanography.  The project also contributed to the Louisiana Seagrant Ocean Commotion event that is geared towards K12 students through hands-on outreach activities demonstrating ocean acidification.

Last Modified: 02/25/2025
Modified by: Kanchan Maiti