To assess the potential impacts from oil and gas production in deep waters of Brazil’s Santos Basin, the Brazilian environmental agency (IBAMA) required PETROBRAS, the main oil company in the basin, to implement the “Projeto de Monitoramento de Praias da Bacia de Santos” (Santos Basin Beach Monitoring Project - PMP-BS). This project has been operating along the states of Santa Catarina, Paraná, São Paulo, and Rio de Janeiro, since August 2015, collecting data from stranded seabirds, turtles, and marine mammals. This dataset includes records from August 2018 to August 2023, along the Paraná and Santa Catarina coastlines. During this period, 58151 animals of at least 93 species were recorded (883 unidentified animals). From this total, 88.6% were dead and 11.4% alive when first observed. This dataset complements previous ones from the same area, and is a high-intensity monitoring effort essential to understand temporal and geographical variation of stranded animals. This data will allow future works aimed at understanding the impacts of human activities on marine ecosystems and environmental changes over time. 

Stranding records were collected along the coast of Santa Catarina and Paraná states, from 28°8'37.56"S / 48°38'42.37"O to 25°58'31.35"S / 48°35'45.61"O. According to their accessibility, each beach had a predefined sampling strategy that was maintained during the project. Beaches were monitored either daily (335.9 Km) or weekly (113.1 Km), preferentially in the morning. Additionally, a toll-free number was made available, so the local population could inform the institution responsible for the sector if an animal stranded after the field team monitored the area. Some beaches in the area (177.6 Km) were not monitored regularly, and animals on them were collected only when there were calls from the public. Records made during regular monitoring or by calls from the local population are identified separately in the data.

All animals observed during beach surveys were recorded. Depending on the carcasses’ decomposition stage, they were either disposed of or taken to the laboratory for necropsy. Sex and development stage were identified using external characters or by direct examination of gonads during necropsy. 

Taxonomic identification was usually done using morphologic characters, but when this was not possible due to decomposition or predation, a molecular analysis was performed, by sequencing the COI gene and identification of the species using the Barcode of Life Data System (Ratnasingham & Hebert, 2007). Taxonomical classification follows the taxa retrieved from the Integrated Taxonomic Information System (ITIS) (http://www.itis.gov) on March 2016.

Animals were collected under IBAMA's license ABIO 640/2015.