Phytoplankton are responsible for the oceans’ uptake of carbon dioxide, but the rate at which phytoplankton grow and take in that carbon is highly dependent on nutrients in the ocean, including zinc. The availability of zinc is impacted by its chemistry and reactions with biological compounds in the ocean. But the element has been hard to study because of its low concentrations in the ocean, and researchers have historically had little insight into when and why it may be available to organisms.

Now Princeton geochemists Satish C.B. Myneni and Jianshu Duan have developed a new method using synchrotron X-rays to understand the way that zinc cycles through the ocean.

“The X-ray method employed in our study provides direct evidence for the transformation of zinc from biological to mineral particles. It opens up the opportunity to study the chemistry of zinc in other systems, such as atmospheric dust and biological samples,” said Duan, a postdoctoral researcher in geosciences at Princeton and a coauthor of the study. “Other elements that are essential to biology like copper and cobalt may experience similar biogeochemical reactions in the ocean, and their cycles can be revealed using a similar approach.”

The findings were published in the journal Science earlier this summer, in collaboration with researchers at Stellenbosch University, University of Chicago, University of California-Santa Cruz and the Max Planck Institute for Chemistry. The scientists believe the work will open the door for researchers to study other metals that are important to ocean health.