The asteroid that likely caused dinosaur extinction 66 million years ago triggered strong global cooling and a massive bloom of algae, causing mass extinction also in marine ecosystems. This is the result of a new study from scientists of the Potsdam Institute for Climate Impact Research (PIK). The researchers simulated the ocean productivity before and after the asteroid impact – and found a brief global algal bloom peaking at a productivity seven times higher than in the pre-impact ocean. Since the algae likely produced toxins, their increase could have contributed to the extinction of species in the ocean.