Deep subsurface fungi found 1,640 feet below Great Lakes could alter carbon sequestration models

A University of Michigan study found 689 species of fungi, including 13 new species, living 1,640 feet below the Great Lakes in the Antrim Shale formation. The fungi feed on organic material trapped in the rock and convert it into CO2, suggesting that deep underground carbon stores may be more biologically active than previously assumed. The researchers estimate a single drop of subsurface water contains about 250 fungal cells, similar to ocean water. They also found tardigrades and segmented worms, indicating complex food webs in these deep environments. The water likely originated from melting Ice Age glaciers 11,000 years ago that carried microorganisms down through fractured rock. Co-author Tim James warns that fungi need to be incorporated into carbon cycling and sequestration models. If subsurface fungi can break down carbon-rich rocks and release CO2, the stability of geo-sequestration as a carbon storage method may need reassessment. The study was published in The ISME Journal.