Study Finds Ocean Deoxygenation Began 8 Million Years Before End-Triassic Extinction
Updated
Updated · Sci.News · Jun 2
Study Finds Ocean Deoxygenation Began 8 Million Years Before End-Triassic Extinction
3 articles · Updated · Sci.News · Jun 2
Summary
Chemical evidence from Alaska rock layers shows shallow-ocean oxygen levels started falling about 8 million years before the end-Triassic mass extinction 201 million years ago, indicating marine stress long predated the die-off.
Geochemical analysis of sediments from the ancient Panthalassan Ocean suggests oxygen loss intensified during the extinction itself and became a major driver of species losses.
The extinction erased about 60% of marine invertebrates at the generic level and has long been linked to Central Atlantic magmatic province volcanism, which researchers say likely triggered warming, acidification and deoxygenation.
Virginia Tech researchers said the earlier oxygen decline may align with another volcanic episode, though its role remains unclear, and argued the ancient sequence offers a warning as modern oceans again face acidification and deoxygenation.
Earth's oceans once took 8 million years to die. As ours change faster, are we accelerating towards the same catastrophic fate?
The current rate of ocean acidification is historically unmatched. Can marine life adapt in time, or is a collapse already inevitable?
The End-Triassic Mass Extinction Revisited: Prolonged Ocean Deoxygenation and Its Modern Implications
Overview
Groundbreaking research published in 2026 by Kayla McCabe and colleagues has revealed that ocean deoxygenation began about 8 million years before the End-Triassic Mass Extinction, much earlier than previously believed. By analyzing chemical traces in ancient rocks, scientists discovered that marine environments were already deteriorating and ecosystems were under stress well before the main extinction event around 201 million years ago. This new timeline, uncovered through geochemical analyses, shows that the loss of ocean oxygen was a prolonged process, fundamentally changing our understanding of how and when ancient marine crises unfolded.