Aspects of biodeposition by oysters and other invertebrate filter feeders

Quantities of suspended matter removed by oysters (Crassostrea virginica) and deposited as feces or pseudofeces varied seasonally, reaching maxima in September. Below 2.8C, measurable quantities were not produced. At certain seasons, levels of suspended solids influenced quantities of biodeposits. Laboratory studies indicated that the oysters on 0.405 hectare of an estuarine bottom may produce up to 981 kg of feces and pseudofeces weekly. Of the particles, 95% were under 3 µ in diameter. all types of algal cells present in the surrounding water were represented. The deposits contained 77–91% inorganic matter, mostly illite, chlorite, and mixed‐layer clays, 4–12% organic carbon, and 1.0 g/kg phosphorus. biodeposits of filter feeders such as barnacles, tunicates, and other lamelli‐branchs were similar to those of oysters. Filter feeders may influence deposition, transport, and the composition of suspended sediments in estuaries. A possible relationship between the removal from suspension and the subsequent deposition of radionuclides associated with particles of clay, silt, or planktonic algae and feces or pseudofeces is suggested