Oyster reefs as processors of estuarine materials

Oyster reefs are dense concentrations of filter-feeding animals in estuarine ecosystems. A flow-through plastic tunnel is a feasible method of determining significant changes in material concentrations in tidal waters passing over an oyster reef. The oyster reef reduces the amplitude of the particulate organic carbon and chlorophyll a signals while increasing the amplitude, of the ammonia signal. The observations suggest that oyster reefs have one of the highest reported release rates of ammonia (1680–7250 μg at.·m−2·h−1), and thus are probably important in material cycles in marsh-estuarine ecosystems. The magnitude of particulate organic carbon removal by the oyster reef is many times greater than that expected from biofiltration alone, suggesting that removal due to physical factors may be important.