Overview
- The Peking University study published July 27–28 in PNAS Environmental Sciences analyzed sediment from 16 sites and found continental-shelf mercury accumulation near 93 micrograms per square metre per year, about 160% higher than preindustrial rates.
- Authors identified two main pathways driving the rise: direct release from ice melt, erosion and weathering, and greater atmospheric uptake by expanding phytoplankton in newly exposed open water.
- The study reports meltwater-sourced mercury inputs up about 550% and atmospheric uptake up about 350% since industrialization, with the rapidly warming Antarctic Peninsula singled out as a major hotspot of ice loss.
- Scientists warn the extra mercury can bioaccumulate through krill-based food webs, and earlier research found roughly 62% of Antarctic seabird species already exceed 'no adverse effect' mercury thresholds.
- Researchers say ecosystem-level consequences remain under study and are calling for expanded monitoring, trophic-transfer research and regional modeling to track risks to wildlife and people who depend on Southern Ocean resources.