Bridging scales from cell-level sinking dynamics to large-scale Arctic export

The vertical export of biological material out of the surface ocean is a key component of biogeochemical cycles and food supply to the deep ocean and benthos. I will present companion studies from the highly-productive Chukchi shelf of the Arctic Ocean, in which we connect traditional sediment trap measurements that integrate across the bulk biological community to small-scale effects of microalgal sinking behavior and physiology. In particular, we used a vertical tracking microscope (Gravity Machine) to measure the sinking speeds of over 2,000 individual microalgal cells and colonies. Export fluxes between the two observational methods align well and highlight distinct drivers—such as physical downwelling, nutrient conditions, and cellular health—of export processes assessed at different scales.