Past and present interactions between ocean chemistry and biology

The step-wise oxygenation of the ocean and atmosphere, from anoxic in the Archean (~4 to 2.5 Gyr ago) to mostly oxygenated conditions in the Phanerozoic (~541 Myr ago to present), was associated with key evolutionary events like the appearance of photosynthesis, eukaryotes, and animals. Intervals of global deoxygenation in the Phanerozoic are often associated with major biotic crises and perturbations to carbon and nutrient cycles. Ocean chemistry and marine life have thus largely co-evolved, particularly through their impact on the availability of nutrients, but the exact causal relationship remains relatively poorly constrained.

We study these interactions on a large range of different temporal scales. These include controls on the bio-availability of essential micronutrients in the surface ocean, the influence of oxygen minimum zones (OMZs) on the availability of micronutrients, the role of micronutrients in sustaining high primary productivity rates during Mesozoic Oceanic Anoxic Events, as well as long-term records studying transitions in nutrient availability for most of Earth’s history.