Life deep in the seabed proceeds very slowly. A team of scientists from Aarhus University (Denmark) and the University of Rhode Island has developed a new method for measuring this slow life deep down in the seabed. Their findings were published last week in the journal Nature.

According to URI Oceanography Professor Arthur Spivack, the relative abundance of amino acids that are mirror images of each other in subseafloor sediment reflects the activity of microorganisms. The research team used this signature to calculate how active microorganisms are in the deepest layers of the seabed.  The researchers found that the metabolism of organic carbon takes place at a much slower rate in the deep seabed compared with all other known ecosystems.

“This study goes far beyond previous studies by showing that microbes in subseafloor sediment replace their biomass thousands of times more slowly than microbes in the surface world,” said URI Oceanography Professor Steven D’Hondt. The mean generation time of bacterial cells in the sediment is correspondingly long – 1,000 to 3,000 years. In comparison, the bacteria that have previously been studied in the laboratory or in nature typically reproduce in a number of hours.

The researchers said that their new method for calculating the pace of life in the seabed can also be used to measure the pace of life in other ancient environments with extremely low biological activity, such as permafrost soils.

For further information, please see the full press release at this link.