The objective of this PhD research was to study the environmental behavior and impact of trace metal elements in the Patos Lagoon system (Baisch, P.: Les Oligo-Elements Metallique du Systeme Fluvio-Lagunare dos Patos (Bresil) - Flux et deverir, Ph.D. thesis, L'Université Bordeaux I, 1994). It also aimed to determine SPM, particulate organic carbon and particulate organic nitrogen fluxes from rivers to the lagoon. SPM was obtained from May 1988 to August 1990 for the Camaquã River and from January 1988 to June 1990 for the Guaíba River following the methodology proposed by Aminot and Chaussepied (1983).