As is common practice for researchers around the world, URI GSO faculty and students share the results of their research with fellow scientists and society by publishing in refereed scientific journals. With so many people conducting so much research, it can be difficult to keep track of recently published articles.  Fortunately, the URI University Libraries maintain a list of works published by GSO faculty and students at this link.

Among the many recent publications by URI GSO faculty are the ones that recently appeared in Nature, and Science, the journal of the American Association for the Advancement of Science.

A team of scientists from Aarhus University (Denmark) and the University of Rhode Island has developed a new method for measuring microbial growth in the deep seabed. Their findings were published in March 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.

Interim Dean D’Hondt was also published in Science in May. In an article whose co-authors include Robert Pockalny, also from URI, the researchers write they found that microbial communities can subsist at depths in marine sediments without a fresh supply of organic matter for millions of years.  Since the microbes in the seabed in the area of study consumed oxygen very slowly, the sediments remained oxygenated tens of meters below the seafloor.  The slow rate of oxygen consumption enables microbial life to exist deep beneath the seabed for 86 million years.

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