Strandings of marine mammals, sea turtles and seabirds along the South Santa Catarina state coastline, from 2015 to 2018.

To assess the potential impacts on seabirds, turtles and marine mammals from oil and gas production from the oceanic Pre-Salt province at Brazil’s Santos Basin, the Brazilian environmental agency (IBAMA) required PETROBRAS, the main oil company in the basin, to implement the “Programa de Monitoramento de Praias da Bacia de Santos” (Santos Basin Beach Monitoring Program - PMP-BS). Since 2015 PMP-BS has been operating along the states of Santa Catarina, Paraná, São Paulo and Rio de Janeiro, to collect biological data from live and dead stranded animals. This dataset comprises the first three years of monitoring (September 2015 to August 2018) along the southern Santa Catarina state coastline, from 28°8’37.558” S 48°38’42.367” W and 28°29’48.831” S 48°45’41.561” W. During this period, 3291 animals of 46 species were recorded, 88.61% of which were dead and 11.39% alive when first observed. This dataset represents the first high-intensity monitoring effort in the area and is essential to establish baselines for future work that seek to better understand the impacts of human activities on marine ecosystems.

Methods
This dataset represents the records of stranded animals made at PMP-BS’ Sector 1 (28°8’37.558” S 48°38’42.367” W and 28°29’48.831” S 48°45’41.561” W), in the state of Santa Catarina, including beaches at Imbituba and Laguna counties. This includes 9 beaches, with a total extent of 39.99 Km, that were monitored daily, preferentially in the morning. Additionally, a toll-free number was made available, so the local population could inform of stranded animals in the area. Records made during regular monitoring or by calls from the local population are identified separately in the data.

The data presented here describe animals recorded from 1 September 2015 to 31 August 2018. All animals observed during beach surveys were recorded. Depending on the decomposition stage, carcasses were either disposed of, or taken to the laboratory for necropsy. Animals that stranded alive and needed veterinary treatment were taken to rehabilitation centers maintained by institutions that are part of the PMP-BS. Sex, development and maturation stage were identified using external characters or by direct examination of gonads during necropsy. All recovered carcasses were submitted to biometry. For fresh carcasses, samples were collected for histopathological analysis, natural history and any other analyses needed to identify the cause of death.

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

Specimens were collected under permit “ABIO No. 640/2015” from Instituto Brasileiro do Meio Ambiente e Recursos Naturais Renováveis – IBAMA.