Deposit Feeders

Deposit feeders are benthic animals that ingest sediment to extract bound organic matter, bacteria, and detritus, then egest the processed mineral fraction. They include many polychaetes, holothurians, and bivalves, and split into surface deposit feeders that graze the sediment-water interface and subsurface feeders that mine deeper layers. Their burrowing and reworking, called bioturbation, mixes sediment, oxygenates deeper layers, and recycles nutrients back to the water column. Deposit feeders dominate fine muddy bottoms rich in organic input, where they form a key trophic link between detritus and higher consumers.