The work investigates the 21 species of macroscopic seaweed belonging to Chlorophyta, Phaeophyta and Rodophyta found in the municipalities of Tramandaí and Imbé, located in the north coast of the State of Rio Grande do Sul, obtained by the scraping method of the substrate during the years 1983 and 1984. Sporadic collections were also carried out in the years 1985, 1986 and 1988.
