Finescale currents, O(1-100 km, days-months), are actively involved in the transport and transformation of biogeochemical tracers in the ocean. However, their overall impact on large-scale biogeochemical cycling on the time scale of years remains poorly understood due to the multi-scale nature of the problem. Here we summarize these impacts and critically review current estimates. We examine how eddy-fluxes and upscale connections enter into the large-scale balance of biogeochemical tracers. We show that the overall contribution of eddy-fluxes to primary production and carbon export may not be as large as for oxygen ventilation. We highlight the importance of finescales to lowfrequency natural variability through upscale connections, and show that they may also buffer the negative effects of climate change on the functioning of biogeochemical cycles. Significant interdisciplinary efforts are needed to properly account for the cross-scale effects of finescales on biogeochemical cycles in climate projections.