Mysterious oil spill in the Atlantic Ocean threatens marine biodiversity and local people in Brazil.

This study provides the first preliminary assessment of the potential impact from the recent oil spill in the Southern Atlantic Ocean. Using information on the occurrence of oil patches along the Brazilian coast, we quantified potential exposure of marine coastal habitats (estuaries, mangroves, beaches, seagrass meadows, tidal flats, and coral reefs) to oil-related disturbances. We also evaluated which threatened species in the coastal zone may have been impacted and the magnitude of the impacts on socioeconomic activities (i.e. artisanal fisheries and local tourism). Estuaries, mangroves, and seagrass meadows had the highest footprint among the habitats assessed. A total of 27 threatened coastal species occur within the area impacted by the oil residue. Approximately 870,000 people, employed in both artisanal fisheries and local tourism, appear to have been affected by the oil spill. We pinpointed priority areas for monitoring of contamination and accumulation in marine biota.