Study finding Australia’s devastating wildfires triggered algal bloom in Ocean; Another study says happened before "The Great Dying"
"Two days later, another study published in Nature Communications revealed that this sort of thing had happened before. In the Permian mass extinction event some 252 million years ago, a combination of greenhouse gas emissions from volcanic eruptions, temperature increases and deforestation created a “poisonous soup” of algal blooms that exacerbated an already dire scenario for life, as study co-author Vivi Vajda of the Swedish Museum of Natural History put it in an interview."
https://www.ecowatch.com/earth-extinction-event-toxic-algal-blooms-2655255553.html