Benthonic foraminifera samples were collected seasonally near several isolated sources of sewage and (or) industrial effluent in the Restigouche estuary. Distinct biotopes based on species diversity and population density are developed locally especially near Dalhousie peninsula and Belledune Point in response to the effects of effluent discharge. Averaged diversity indices calculated in known polluted describe an initially depressed curve that reflects the development of near-abiotic conditions close to the effluent source and, at some distance offshore, an anomalously high diversity which may be indicative of a zone near each outfall in which certain components of the effluent generate a temporary favorable artificial environment. TheElphidium incertumlclavatum group usually dominates the living fauna near sewage outfalls and appears to be able to invade and maintain itself on nearshore sediment substrates which have pH values in excess of 6.4.