New research indicates that the Earth's largest extinction event, the Permian-Triassic extinction 252 million years ago, destabilized ocean biogeochemical cycles, leading to prolonged oscillations in carbon, oxygen, and phosphorus levels. This delayed the recovery of marine ecosystems.
Scientists used a dynamical systems model to analyze the coupled cycles of phosphorus, carbon, and oxygen during the end-Permian to early Triassic period. The model examined the effects of the Siberian Traps volcanic eruptions and the collapse of terrestrial ecosystems on ocean stability. The Permian-Triassic extinction event, also known as the "Great Dying," wiped out approximately 95% of marine species.
The study found that the emplacement of the Siberian Traps and ecosystem collapse increased ocean phosphorus levels and decreased oxygen, making the system sensitive to marine organic carbon burial. A shift towards smaller phytoplankton, which are more efficient at nutrient uptake, further destabilized the ocean by increasing oxygen demand and homogenizing redox conditions. The model demonstrated that these factors, rather than short-term carbon inputs, drove the observed oscillations in geochemical data. These findings highlight the profound impact of the Permian-Triassic extinction event on Earth system stability, prolonging hothouse conditions and recurrent ocean anoxia.