Southern Ocean sediment cores show plankton communities changed before ancient warming event

Deep-sea sediment cores reveal major ecological turnover in plankton communities before a significant warming event 56 million years ago. Researchers found that a smaller, preceding warming event destabilized high-latitude plankton communities approximately 200,000 years before the Paleocene-Eocene Thermal Maximum (PETM). This pre-event instability influenced how plankton responded to the larger PETM warming. The study, focusing on Southern Ocean sediment cores, suggests even minor environmental changes can significantly impact marine ecosystems, offering insights into modern climate change effects.