Modeling the onset of photosynthesis after the Chicxulub asteroid impact

TL;DR

This study models phytoplankton photosynthesis immediately after the Chicxulub impact, suggesting rapid recovery potential despite extreme atmospheric conditions, highlighting biosphere resilience.

Contribution

It provides the first preliminary model of phytoplankton photosynthesis under post-impact atmospheric conditions, emphasizing resilience and recovery potential.

Findings

Phytoplankton could photosynthesize effectively despite no ozone.

Recovery of phytoplankton likely rapid after impact.

Biosphere resilience to environmental stress is significant.

Abstract

We do a preliminary modelling of the photosynthetic rates of phytoplankton at the very beginning of the Paleogene, just after the impact of the Chicxulub asteroid, which decisively contributed to the last known mass extinction of the Phanerozoic eon. We assume the worst possible scenario from the photobiological point of view: an already clear atmosphere with no ozone, as the timescale for soot and dust settling (years) is smaller than that of the full ozone regeneration (decades). Even in these conditions we show that most phytoplankton species would have had reasonable potential for photosynthesis in all the three main optical ocean water types. This modelling could help explain why the recovery of phytoplankton was relatively rapid after the huge environmental stress of that asteroid impact. In a more general scope, it also reminds us of the great resilience of the unicellular biosphere against huge environmental perturbations.