This article presents results of ethnographic research on modern fishers and mollusk gatherers from the state of Santa Catarina, in southern Brazil. Information from interviews is correlated with questions regarding the lifeways of groups that built large shell mounds along the Brazilian coast between 6,000 and 1,000 years ago. Ethnoarchaeological research helps deconstruct misconceptions regarding these prehistoric communities, demonstrating that large-scale sedentary groups could have successfully utilized estuarine resources on a yearround basis.