Profiles of210Pb,210Po, and nutrients were measured within a cold, chlorophyll‐rich filament observed in satellite images off Point Arena, California. The most striking observation was the large excess of210Po in the surface water of near‐shore filament stations. This excess210Po, typically associated with the breakdown of particles in the upper thermocline, is indicative of the transport of recently upwelled water seaward within the filament. Its large inventory and association with NO2within the filament surface is consistent with the filament being part of a continuous, meandering, southward flowing jet within the California Current. Nutrients and biomass are “pumped” along the meander path by the interaction of biological processes (production, grazing) and vertical motion (upwelling, downwelling). Products of particle breakdown, such as NO2and210Po, are continuously recycled and accumulate along the meander path. The implication is that within the coastal transition zone, some portion of the nutrients incorporated into new production has also been regenerated along the meandering flow. The excess210Po is removed from the chlorophyll‐rich filament at a rate which is approximately an order of magnitude greater than210Po removal from open ocean surface water. This suggests that the scavenging rate of210Po, like that of234Th, varies with the rate of primary p