Abstract
Advective transport of artificial and natural particles into permeable sediments was demonstrated in situ by field experiments in an intertidal Wadden Sea sandflat. Using dyed sediment, advective interfacial solute exchange was shown to reach down at least 1.5 cm below surface. Particle depth distributions depended on sediment permeability and particle size. Sandy sediments were found to efficiently trap particulate material. At the beginning of the local phytoplankton spring bloom, an average m 2 of coarse‐grained sediment received 850‐mg organic carbon per day by filtration of 14 liters of overlying water per hour. We discuss the relative importance of different transport mechanisms, and data from parallel studies on natural sediments at the same site are interpreted in close correlation to the results of the in situ experiment.