Limited impact on oysters in first-of-its-kind field trial of marine carbon dioxide removal (mCDR) strategy

Carbon dioxide removal (CDR) is a necessary component of limiting global warming to 2°C by 2100. Marine enhanced rock weathering (mERW) with minerals like olivine is a CDR strategy with the potential to capture atmospheric carbon dioxide and mitigate ocean acidification, which threatens calcifying organisms including those essential for global aquaculture such as oysters. mERW could benefit these species, although olivine releases trace metals like nickel which may bioaccumulate. This study reports findings from the world’s first field trial of mERW, conducted in NY, USA. After a year of exposure to olivine, Eastern oysters showed no significant difference in biomass between Olivine and Control treatments, and mean metal accumulations were below US Food and Drug Administration warning thresholds and within global natural ranges. Our findings suggest that mERW with olivine has a limited effect on oysters and olivine-derived metals did not result in oyster safety concerns for human health.