Samarco

When the Fundão dam collapsed in Brazil, 50 million m 3 of iron ore tailings were released into the Doce river, resulting in the world's largest mining disaster. The contaminated mud was transported 668 km downstream of the Doce river and reached the Atlantic Ocean 17 days after the collapse. Seven months later, there was evidence that the tailings had reached the largest and richest coral reef formation in the South Atlantic Ocean. This study provides the first description of species composition, abundance, and diversity patterns of fish assemblages in estuaries, coastal areas, and coral reefs affected by the rupture of the mining dam in the Doce river. A linear mixed model (GLMM) was used to evaluate the influence of salinity on fish abundance across estuarine and coastal ecosystems. In addition, based on functional traits related to habitat use and feeding habits, this study
identi fi ed fi sh species suitable as bioindicators of the long-lasting effects of this major mining disaster. Bottom
trawls were used to sample fi ve estuaries and their respective coastal areas, and a visual census was employed
to sample fi ve reef areas, representing an impact gradient. A total of 269 species were recorded in all three habitats, but only seven were shared among them. The results showed lower similarity in assemblages among estuarine areas compared to the coastal and reef areas. Species composition among estuaries and reef ecosystems was
more heterogeneous. In contrast, coastal habitats exhibited high homogeneity. Salinity had no statistically significant effect on fi sh abundance either in estuaries (p = 0.22) and along the coast (p = 0.14). Twelve fish species
were identi fied as suitable bioindicators for evaluating the long-lasting effects of resuspension of contaminated
sediments. These species are commonly found in the ecosystems under the in fluence of the disaster inhabiting
potentially contaminated substrates and substrate-associated benthic preys.

On November 5, 2015, the rupture occurred of the Fundão dam of the mining company Samarco, located in the sub-district of Bento Rodrigues-MG, 35 km from the center of the Brazilian municipality of Mariana-MG, approximately 16.000 Olympic pools of mining residue circulated through the district of Bento Rodrigues in a period of only 11 minutes. The plume of this environmental impact extended approximately 800 km in the Rio Doce basin, between Minas Gerais and Espirito Santo. The Ipiranga river, located between Linhares and São Mateus, was one of the last sites affected by the waste from the Doce river basin, having contact with the sea in the Urussuquara-ES restinga, a place that is a nursery of biodiversity, especially the marine and estuarine ichthyofauna, besides being of great importance for artisanal fishing and ecotourism. The present study aimed to monitor the Ipiranga River and Urussuquara Beach for all seasonal seasons, beginning in September 2017 and ending in May 2018, the following variables were analyzed: dissolved oxygen, electrical conductivity, hydrogenation potential (pH), transparent, temperature, depth and total dissolved solids, comparing them to the Resolution CONAMA n°. 357, de 17/03/2005, with the purpose of evaluating the quality of estuarine and marine waters. The results found were alarming and evident foci of negative impacts on the aquatic ecosystem and society dependent on artisanal fishing for their subsistence.