Selenium can trace ocean oxygen history

LEICESTER, England, June 23 (UPI) -- British scientists say they've found the chemical element selenium can be used to determine how oceans' oxygen content has changed.

Selenium belongs to a group of elements whose behavior is controlled by the concentration of oxygen in the environment, the investigators said.

The scientists, led by University of Leicester researcher Andrew Shore, say the study represents a first attempt to measure the isotopic ratios of selenium in sediments.

One possible outcome, the researchers said, is the results could give scientists a global picture of the changing oxygen content of the oceans through time. Previous studies have tended to focus on local variations in ocean oxygen content.

The oxygen content of oceans can also be used as an indicator of their "overall health," the scientists say.

"Our understanding of the changes in atmospheric oxygen is good, but our planet is 70 percent covered by oceans," Shore said. "Determining the oceanic oxygen content is very difficult -- it is linked to the atmosphere, plankton growth, and ocean circulation patterns."

The research is to be presented Thursday during the University of Leicester's "Festival of Postgraduate Research."