How Algae Helped Some Life Outlast Extinction: A New Study Reveals the Power of Cooler Waters
The Earth's largest mass extinction event, known as the Great Dying, occurred around 252 million years ago, wiping out the majority of marine and terrestrial life. But a new study published in AGU Advances suggests that cooler, relatively high-latitude marine environments may have been refuges for species escaping volatile climate conditions elsewhere. The research, led by Buchwald et al., examined rock samples from the Arctic archipelago of Svalbard, Norway, and identified high levels of lipid biomarkers in rocks dated soon after the Permian-Triassic extinction.
These biomarkers, produced by a group of phytoplankton, indicate that the cooler waters of the paleo-ocean allowed this primary producer to bloom and sustain remaining sea life. The study compared 32 rock samples from Svalbard with samples from other locations, such as northern Italy, southern China, and Türkiye, all representing warmer regions surrounding the prehistoric Tethys Ocean. The team examined the samples for C33–n-alkylcyclohexane (C33–n-ACH) and phytanyl toluene, molecular fossils that act like fingerprints of ancient marine life.
The findings revealed that C33–n-ACH levels were 10 times higher in Svalbard samples dated after the extinction event, suggesting a true increase in the biomarker. In contrast, warmer regions detected far less C33–n-ACH, but a similar increase in abundance after the extinction event. Phytanyl toluene was largely absent from Svalbard samples before the extinction and showed a dramatic increase in its aftermath, further supporting the idea that cooler waters were essential for the survival of marine life.
These results indicate that the phytoplankton producers of these biomarkers remained stable and thrived in cooler waters during a time when warmer waters were unable to support significant marine life. The study highlights the critical role of algae in helping some life outlast the mass extinction event, providing valuable insights into the resilience of marine ecosystems in the face of environmental changes.
