Natureza & Conservação Natureza & Conservação
Nat Con 2016;14:35-45 DOI: 10.1016/j.ncon.2016.10.003
Essays and Perspectives
Deep into the mud: ecological and socio-economic impacts of the dam breach in Mariana, Brazil
Geraldo Wilson Fernandesa,b,, , Fernando F. Goulartc, Bernardo D. Ranierid, Marcel S. Coelhoa,e, Kirsten Dalesf, Nina Boescheg, Mercedes Bustamanteh, Felipe A. Carvalhoa, Daniel C. Carvalhoi, Rodolfo Dirzob, Stephannie Fernandesj, Pedro M. Galettib,k, Virginia E. Garcia Millang, Christian Mielkeg, Jorge L. Ramirezk, Ana Nevesa, Christian Rogassg, Sérvio P. Ribeirol, Aldicir Scariotm, Britaldo Soares-Filhoc
a Evolutionary Ecology & Biodiversity, Department of General Biology, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
b Department of Biology, Stanford University, Stanford, United States
c Master in Modeling and Analysis of Environmental Systems, Center for Remote Sensing, Department of Cartography, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
d Norman B. Keevil Institute of Mining Engineering, University of British Columbia, Vancouver, Canada
e Laboratory of Phenology, Department of Botany, Instituto de Biociências (IB), Universidade Estadual Paulista (UNESP), Rio Claro, SP, Brazil
f Canadian International Resources & Development Institute, University of British Columbia, Vancouver, Canada
g Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Geodesy and Remote Sensing Department, Potsdam, Germany
h Department of Ecology, Universidade de Brasília, Brasília, DF, Brazil
i Department of Zoology, Pontifícia Universidade Católica de Minas Gerais (PUC-Minas), Belo Horizonte, MG, Brazil
j Faculdade de Direito Milton Campos, Nova Lima, MG, Brazil
k Department of Genetics and Evolution, Universidade Federal de São Carlos, São Carlos, SP, Brazil
l Department of Biodiversity, Evolution and Environment, Institute of Exact and Biological Sciences, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil
m Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica (PqEB), Brasília, DF, Brazil
Received 17 May 2016, Accepted 14 October 2016
Abstract

We review the ecological and socio-economic impacts of the catastrophic dam failure in Mariana, Brazil. Tailing management practices by Samarco mining company ultimately caused a dam breach that abruptly discharged between 55 and 62millionm3 of tailings into the Doce River watershed. On November 5th, 2015, a tsunami of slurry engulfed the small district of Bento Rodrigues, loading the Doce River and its estuary with toxic tailings along a 663.2km trajectory, extending impacts to the Atlantic coast. Acute ecological impacts will adversely affect livelihoods of more than 1 million people in 41 riparian municipalities by reducing local access to fisheries resources, clean water, crop production sites, hydroelectric power generation and raw materials. The threats to riverine human communities are particularly critical for the disadvantaged populations from remote areas that rely on subsistence agriculture and fisheries, and are uniquely vulnerable to long-term heavy metal exposure. At the landscape scale, we predict multiple negative impacts, ranging from alterations of the genetic diversity of fish populations to long-term vegetation loss and poor regeneration in contaminated areas. Consequently, compromised soil stability and runoff control will increase the risk of further geomorphologic disturbance, including landslides, bank failure and mass movements. We propose spatially explicit long-term monitoring frameworks and priority mitigation measures to cope with acute and chronic risks. We posit that, from a national perspective, disastrous impacts like that of Doce River may become more frequent, given the recent regulatory changes that undermine both institutional governance structures and enforcement of environmental regulation.

Keywords
Ecosystem services, Environmental contamination, Environmental legislation, Heavy metals, Mining, Restoration, Water resources