Elimination of Bacteria by the Soft Shell Clam, Mya arenaria

Abstract

Factors significant to the uptake and elimination of coliform bacteria by the soft shell clam, Mya arenaria, were investigated. Uptake kinetics resembling those in the northern quahaug suggest that a steady state exists in functioning animals wherein the number of organisms taken in and eliminated are in balance. In contrast to the quahaug, most of the animals accumulate the organisms very shortly after being placed in the environmental water. The lower limits on the temperature, salinity, and flow rate of the environmental water for acceptable elimination (depuration) were about 10 C, 20‰, and 7 ml/rain per animal respectively. In the feasibility study for a flow-through depuration system using naturally polluted animals, consistently good elimination to very low elevated temperature (ET) coliform levels was observed if the initial level of contamination did not exceed about 2000 ET coliforms per 100 g. Results comparable with those in the flow-through system were obtained in a recirculating depuration system, thereby indicating the feasibility of the recirculating depuration system for the elimination of coliforms in marginally polluted animals.