Heterogeneous grain size distribution in tidal flat sediment caused by bioturbation activity of Arenicola marina (polychaeta)

In a series of laboratory experiments, especially in an "indoor tidal flat ecosystem", the effects of deposit feeding by the European lugworm Arenicola marina L. on the sediment were studied. Feeding activity did not so much result in a biogenic graded bedding, but more in an increasing heterogeneous distribution of the several grain size fractions over the sediment. A mechanism which causes these effects is proposed: the chance of a particle to stick to the mucus covered papillae on the lugworm's proboscis and to be swallowed depends on its surface area; smaller particles have a greater chance than large ones.