Steven D’Hondt is an American geomicrobiologist who studies microbial communities living beneath the seafloor.
He became an assistant professor in the Graduate School of Oceanography at the University of Rhode Island in 1989, where he remains today.
In a 2015 study, D’Hondt led a research group that demonstrated that oxygen penetrates the entire sediment column in as much as one third of the world’s oceans.
[4][5][6] This oxygen affects microbial metabolism in these sediments and may be transported into the underlying mantle.
In 2021, his group published evidence that splitting of water by natural radiation is the principal energy source for microbial communities in marine sediment older than a few million years.