YOUNG SCIENTIST AWARD (DONATH MEDAL): TRACKING AND MODELING THE DEVELOPMENT OF THE SEDIMENTARY MIXED LAYER
An equally critical question is when and how in Earth’s history bioturbators began to substantially influence marine biogeochemistry. Recent modeling work has suggested that even limited early Paleozoic bioturbation could have driven productivity crises and ocean-wide deoxygenation—in striking contrast to macroevolutionary and macroecological predictions. In order to move forward this debate, I will present new diagenetic modeling data exploring, in a quantitative and process-based manner, the relationship between bioturbation and global nutrient cycling—focusing on phosphorus (the ultimate limiting nutrient on geological timescales). In contrast to previous modeling work, I find that bioturbation does not uniformly or unidirectionally mediate increased phosphorus burial. Bioturbation does, however, appear to have enhanced the sensitivity of carbon and oxygen cycling to environmental perturbations.