113-million-year-old fossils reveal how volcanic CO2 caused plankton extinction
Tiny fossils reveal ocean acidification caused a major planktic foraminifera extinction. Massive volcanic eruptions released carbon dioxide, making ocean waters more acidic. This chemical shift hindered shell formation for these vital marine organisms. Researchers used calcium isotopes in shells to find this missing evidence. The findings offer insights into modern ocean acidification's potential…
Scientists have discovered ancient fossil evidence linking massive volcanic eruptions to a significant extinction event among planktic foraminifera, small shell-building organisms crucial to Earth's carbon cycle. The extinction occurred 113 million years ago during the Early Cretaceous period, likely triggered by the Kerguelen Plateau's volcanic activity in the southern Indian Ocean.
These eruptions emitted large amounts of carbon dioxide, which dissolved in seawater, increasing ocean acidity and making shell formation more challenging. Chemical signals preserved in fossilized calcium carbonate shells revealed a sharp rise in calcium isotope ratios corresponding to the extinction period, indicating slower-than-usual shell-building.
The Kerguelen Plateau's eruptions released carbon dioxide on a scale sufficient to alter ocean chemistry and cause widespread impacts on marine life. The study's meticulous analysis of fossil specimens from the Falkland Plateau in the South Atlantic, collected in the 1980s, revealed surface-dwelling planktic foraminifera experienced a more severe decline in shell formation compared to their benthic counterparts living on the seafloor.
The findings highlight the vulnerability of surface-dwelling shell-builders to increasing ocean acidity and underscore the ongoing relevance of this ancient lesson in the context of modern human-induced climate change.
Written by urgent.news from Times of India's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
