The 'Programa de Monitoramento Ambiental do Porto do Rio Grande' is the network responsible for the data and counts with more than 30 scientists from different laboratory units of the 'Instituto Oceanográfico' at FURG. The sampling program was defined by the Brazilian National Environmental Agency (IBAMA). Annual reports since the year 2000 gather a number of large data sets related to the local aquatic environment covering the lower Patos Lagoon Estuary and the adjacent Atlantic Ocean. It also covered dredging campaigns, and environmental reports of seasonal samplings until the year 2017. Despite the intensive coverage of biological data in the reports, here we present only SPM data. More recent information can be found at the 'Porto do Rio Grande' website http://www.portosrs.com.br/site/responsabilidade_ambiental.php. Data were made available under the Port of Rio Grande data policy. Water samples were obtained on the surface, middle depth and bottom. Water sampling was carried out at sampling stations located along the estuarine access channel (Canal do Rio Grande), and in 'Porto Velho' (Canal do Norte). Water samples were processed following methods proposed by Baumgarten et al. (Baumgarten, M., Rocha, J., and Niencheski, L.: Manual de Análises em Oceanografia Química, FURG, Rio Grande, Brazil, 1996 and Baumgarten, M., Wallner-Kersanach, M., and Niencheski, L.: Manual de Análises em Oceanografia Química, FURG, Rio Grande, Brazil, 2010).