I am an observational biogeochemist with a main focus on the factors that control the downward flux of material from the top of the ocean into the interior and from there to the seabed. Amongst other approaches this involves long term deployments of sediment traps deep in the water column (eg 3000m). A crucial factor is the export flux of material from the upper mixed layer and we have developed a drifting sediment trap, PELAGRA, which makes direct measurements of this flux, a rate which is notoriously difficult to measure.