Influence of the lugworm Arenicola marina on porewater nutrient profiles of sand flat sediments

Abstract

Bioturbation by the lugworm Arenicola marina L. caused specific changes in porewater nutrient profiles of sandflat sediments. In 2 in situ container experiments, A, manna increased nitrate and decreased ammonia concentrations at the depth ot its burrows. This indicates that A. marina stimulates nitrification in this sediment layer through oxygen supply via its ventilation current. The enlarged zone of nitrification promotes denitrification and thereby, nitrogen release from sediments. Silicate concentrations in the porewater were also affected by A. marina bioturbation. Silicate was flushed out of the sediment with the ventilation current. These findings emphasize the important role of A. marina for nutrient release from Wadden Sea sediment