Cal State Monterey Bay senior research scientist AJ Purdy is among the authors of a new study that appears July 17 in the prestigious science journal Nature. 

Led by principal investigator Melissa Rohde, an ecohydrologist who formerly worked with the Nature Conservancy of California and now runs her own environmental consulting firm, Purdy is one of 22 other authors listed in the paper “Groundwater-dependent ecosystem map exposes global dryland protection needs.”

In a news release, Rohde said the paper represents “the first time that groundwater-dependent ecosystems have been mapped on a global scale.”

The study goes further, combining that information with data on local land policies and changes in climate to evaluate which ecosystems are most endangered by retreating groundwater levels. 

“Until now, the location of these ecosystems has been largely unknown, hindering our ability to track impact, establish protective policies and implement conservation projects to protect them,” Rohde said.

The study found 53% of the ecosystems in question are in areas with known groundwater depletion, while only 21% exist on protected lands or regions with policies in place for their protection. Often, even those policies are inadequate, the study concludes.

Purdy, who came to CSUMB nearly two years ago, characterized his contribution to the study as “on the smaller size.” He processed NASA satellite data that measured changes in water storage to determine how vulnerable some of the identified environments were. 

“Melissa and the teams at The Nature Conservancy and the Desert Research Institute did amazing work to identify where these ecosystems are around the world,” Purdy said. “The study provides a global perspective on which groundwater-dependent ecosystems may be at risk. My role on this project was to support evaluating risk from the lens of changes in water storage.”

Being published in Nature is considered a sizable feather in a researcher’s cap. 

“It was great to be included on this project team,” Purdy said, “and to contribute to this impactful research.”