The production of species belonging to the detrital trophic level was investigated in a model-sized aquaculture system, with flowing, filtered seawater and controlled phytoplankton addition to experimental tanks containing the oyster, Crassostrea virginica. The biodeposits of feces and pseudofeces of the oysters supported on the bottom of one tank a population of the nereid polychaete, Nereis virens and in the other tank a mixed community of the capitellid polychaete, Capitella capitata and the amphipod, Corophium sp....