ABSTRACT

This chapter evaluates the effectiveness of an operating, commercial controlled purification (CP) facility in Maine for depurating coliform bacteria, vibrios, and specific bacterial pathogens from oysters, mussels, quahogs, and soft-shell clams harvested from restricted Maine waters. Discharge of inadequately treated sewage from wastewater treatment plants and other sources to coastal US waters has resulted in the contamination of vast areas of shellfish beds with potentially hazardous microorganisms. Shellfish harvesting from moderately polluted areas is allowed only when shellfish undergo CP, or depuration, to remove potentially pathogenic microorganisms prior to marketing or consumption. The process of controlled purification at the Spinney Creek Oyster Company in Eliot, Maine was effective in eliminating fecal coliforms bacteria from different species of shellfish. An important factor was the operation of the facility, where shellfish were maintained under conditions that minimized stress during the CP process.