This biodeposition can be extremely important in regulating water column processes (Newell, 2004). Nitrogen excreted by the bivalves and regenerated from their biodeposits is recycled back to the water column to support further phytoplankton production. Where biodeposits are incorporated into surficial aerobic sediments that overlay deeper anaerobic sediments, microbially mediated, coupled nitrification-denitrification can permanently remove nitrogen from the system as N2 gas.