Polycyclic aromatic hydrocarbons in estuarine sediments as a consequence of the mine tailings remobilization and transport in the Rio Doce basin.

The Fundão dam failure in 2015 severely impaired the economy, the lives of riverine communities, and the aquatic ecosystems of the Rio Doce basin in southeast Brazil. Several contaminants, including polycyclic aromatic hydrocarbons (PAHs), were transported downstream, deposited in the estuary, and released into the Atlantic Ocean. The high concentration of PAHs in estuarine sediments may pose ecological risks and deleterious effects to benthic organisms, so here we aimed at determining the source and fate of these compounds before and after the tailings' arrival. The mean concentration of the analyzed Σ16PAHs increased from 34.05 µg kg-1 in the prefailure period to 751.77 µg kg-1 one year after the arrival of the tailing. The classification of the sediment quality changed from low to moderate contamination. Our results suggest that there was PAHs remobilization by mine tailings along the Rio Doce basin. The target analytes exhibited mostly a pyrolytic profile from fossil fuel and biomass burning. In addition to other contaminants deposited in the estuary after the arrival of the tailings, this study revealed that the profile change of PAHs in the estuary region is a consequence of the mud's erosive power. Integr Environ Assess Manag 2024;20:169-178. © 2023 SETAC.

Applying multivariate techniques to fingerprint water quality impact of the Fundão Dam breach within the Rio Doce basin.

The Fundão Dam breach on 5 November 2015 (the "Event") released tailings, water, soil and/or sediments, and other debris to downstream watercourses. This breach included both direct and indirect impacts from scouring of soils and sediments along and within the affected courses. Multivariate statistical techniques were used to determine the potential of fingerprinting the impact of the breach compared to pre-Event water quality conditions and unaffected watercourses. The selection of key parameters is an important first step for multivariate analyses. Analysis of too many parameters can mask important trends and relationships, while analysis of too few may miss significant water quality indicators. A two-phased selection process was used to identify key parameters that indicated impact from the Event: (a) unbiased, principal component analysis to extract chemically dominant profiles among all measured parameters and (b) comparison of metals' concentrations between unaffected soils and/or sediments and tailings samples. Radar charts of key parameters along with statistical comparisons to pre-Event and not-affected waterways were then aggregated over space and time to assess impact and potential recovery to pre-Event conditions. Nine parameters were identified that characterize tailings-related (direct) and background soil and/or sediment-related (indirect) impacts. Spatially and temporally aggregated radar charts and nonparametric Mann-Whitney U tests were used to assess the statistical significance of these impacts during each wet season since the breach. Indirect parameters, like aluminum and lead, returned to pre-Event levels in the first wet season after the Event. By the 2018/2019 wet season, most of the direct and indirect parameters had returned to pre-Event levels. Integr Environ Assess Manag 2024;20:133-147. © 2023 NewFields Companies, LLC. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

A large scale temporal and spatial environmental DNA biodiversity survey of marine vertebrates in Brazil following the Fundão tailings dam failure.

Seawater contains a wealth of genetic information, representing the biodiversity of numerous species residing within a particular marine habitat. Environmental DNA (eDNA) metabarcoding offers a cost effective, non-destructive method for large scale monitoring of environments, as diverse taxonomic groups are detected using metabarcoding assays. A large-scale eDNA monitoring program of marine vertebrates was conducted across three sampling seasons (Spring 2018, Autumn 2019; Spring 2019) in coastal waters of Brazil. The program was designed to investigate eDNA as a testing method for long term monitoring of marine vertebrates following the Fundão tailings dam failure in November 2015. While no baseline samples were available prior to the dam failure there is still value in profiling the taxa that use the impacted area and the trajectory of recovery. A total of 40 sites were sampled around the mouths of eight river systems, covering approximately 500 km of coastline. Metabarcoding assays targeting the mitochondrial genes 16S rRNA and COI were used to detect fish, marine mammals and elasmobranchs. We detected temporal differences between seasons and spatial differences between rivers/estuaries sampled. Overall, the largest eDNA survey in Brazil to date revealed 69 families from Class Actinopterygii (fish), 15 species from Class Chondrichthyes (sharks and rays), 4 species of marine and estuarine mammals and 23 species of conservation significance including 2 species of endangered dolphin. Our large-scale study reinforces the value eDNA metabarcoding can bring when monitoring the biodiversity of coastal environments and demonstrates the importance of collection of time-stamped environmental samples to better understand the impacts of anthropogenic activities.

Scorpion Stings in Minas Gerais (Brazil): A Monocentric Retrospective Study Evaluating All Envenoming Cases of Local Scorpionism.

INTRODUCTION: We aim to provide better insights into the demographic, epidemiological, and seasonal characteristics of scorpion envenomation reported in the Rio Doce Valley, Brazil. METHODS: We conducted this monocentric retrospective descriptive study with data on Investigation Forms of Accidents by Venomous Animals, only envenoming cases of scorpion stings, between January 1, 2017 and December 31, 2020, belonging to the compulsory notification system of the Municipal Hospital of Governador Valadares. RESULTS: There were 3032 accidents, and the male-to-female ratio was 1.17:1 (male, 54%; females, 46%). Accidents occurred every month, but there was an increase in June, July, and October to January. In most cases, the time between the scorpion sting and medical care was between 1 and 3 h (n=1304; 43%). The most frequent clinical and systemic manifestations were pain at the bite site (94%) and vagal symptoms (7%). Cases were mild (n=2750, 91%), moderate (n=221, 7%), and severe (n=56, 2%). Children younger than 10 y constituted the most cases, 522 (17%). There was a significant difference between clinical severity and age (P<0.01). Ten patients developed acute pulmonary edema. Two 4-y-old children died. All severely envenomated patients as well as 74% and 2% of mild and moderately envenomated patients, respectively, received specific scorpion antivenoms. CONCLUSIONS: Scorpion envenomation is of greater severity in children aged <10 y. The clinical presentation includes mainly local pain associated with vagal symptoms. Accidents occur every month, but there was an increase in June, July, and October to January.

Transition of an estuarine benthic meiofauna assemblage 1.7 and 2.8 years after a mining disaster.

Background: Estuaries are transitional coastal ecosystems that are threatened by multiple sources of human pollution. In 2015, mining tailings from an upstream dam failure caused massive metal contamination that impacted benthic assemblages on the Brazilian Rio Doce estuary. Methods: In this study, we investigate and compare meiofaunal assemblages with eDNA metabarcoding 1.7 years (2017) and 2.8 years (2018) after the initial contamination by mine tailings in order to evaluate the continued impact of sediment mine tailing contaminants on the structure of benthic assemblages after the disaster. Results: The community was dominated by Arthropoda and Nematoda 1.7 yr after the impacts (42 and 29% of meiofaunal sequence reads, respectively) but after 2.8 years Arthropoda (64.8% of meiofaunal sequence reads) and Rotifera (11.8%) were the most common taxa. This continued impact on meiofaunal assemblage revealed a lower phylogenetic diversity (7.8-fold) in 2018, despite overall decrease in metal concentration (Al, Ba, Cr, As, Fe, Zn, Mn, Pb, Cd, Co) in sediments. Our data suggests that differences in benthic assemblages and loss of diversity may be influenced by contaminants in sediments of this estuary, and indicate that broad eDNA assessments are greatly useful to understand the full range of biodiversity changes in dynamic estuarine ecosystems.

Role of indigenous microorganisms and organics in the release of iron and trace elements from sediments impacted by iron mine tailings from failed Fundão dam.

After Fundão Dam failure in 2015, most of Gualaxo do Norte River in Doce River Basin in Brazil became silted by iron mining tailings consisting mainly of fine-grained quartz, hematite, and goethite. Previous work pointed to the possibility of reductive dissolution of iron and manganese from tailings, leading to mobilization of iron, manganese and trace elements. Several microorganisms were shown to reduce Fe(III) to Fe(II) and Mn(III, IV) to Mn(II) "in vitro", but their roles in mobilization of Fe and trace elements from freshwater sediments are poorly understood. In this work, bottom sediments and water collected in Gualaxo do Norte River were used to build anoxic microcosms amended with acetate, glucose or yeast extract, in order to access if heterotrophic microorganisms, either fermenters or dissimilatory Fe reducers, could reduce Fe(III) from minerals in the sediments to soluble Fe(II), releasing trace elements. The Fe(II) concentrations were measured over time, and trace elements concentrations were evaluated at the end of the experiment. In addition, minerals and biopolymers in bottom sediments were quantified. Results showed that organic substrates, notably glucose, fuelled microbial reduction of iron minerals and release of Fe(II), Mn, Ba, Al and/or Zn from sediments. In general, higher concentrations of organic substrates elicited mobilization of larger amounts of Fe(II) and trace elements from sediments. The results point to the possibility of mobilization of huge amounts of iron and trace elements from sediments to water if excess biodegradable organic matter is released in rivers affected by iron mine tailings.

Why is Brachiaria decumbens Stapf. a common species in the mining tailings of the Fundão dam in Minas Gerais, Brazil?

Currently, more than five years after the Fundão dam failure in Mariana, Minas Gerais, Brazil, Brachiaria decumbens Stapf. is the main grass in pasturelands affected by the mining tailings. The aim of this study was to investigate the reason for this fact as well as to determine the ecophysiological effects of mining tailings on B. decumbens and to test whether mixing the tailings with unaffected local soil enhances the affected soil properties. For the experiment, two different soils were collected, one unaffected soil without mining tailings (Ref) and the mining tailings (Tec), and we also created a mixture with 50 % of each soil type (Ref/Tec). We cultivated B. decumbens in the three soil treatments in a greenhouse for 110 days and evaluated soil physical-chemical properties and plant ecophysiology. Our results show that the tailings (Tec) compromised the normal ecophysiological state of B. decumbens. The species survived these adverse conditions due to its great efficiency in acquiring some elements. The soil management tested by this work mitigated the stress caused by tailings and can represent an alternative for the environmental recovery of the affected soils.

Anadenanthera colubrina (Fabaceae) logs in the Atlantic Forest biome: first host plant for Thoracibidion lineatocolle (Col: Cerambycidae) and a new host for Temnopis megacephala (Col: Cerambycidae) / Troncos de Anadenanthera colubrina (Fabaceae) no bioma da Mata Atlântica: primeira planta hospedeira de Thoracibidion lineatocolle (Col: Cerambycidae) e uma nova planta hospedeira para Temnopis megacephala (Col: Cerambycidae)

Wood-boring beetles develop in live trees and dead wood, performing ecological services such as decomposition and regulation of forest resources. Species of the Cerambycidae family, widely distributed in the world, bore into the trunks of trees and dead wood in native and cultivated areas. The objective is to report the first host plant for Thoracibidion lineatocolle (Thomson, 1865) (Coleoptera: Cerambycidae) and a new host plant for Temnopis megacephala (Germar, 1824) (Coleoptera: Cerambycidae) in the Brazilian Atlantic Forest biome. Three logs, with one-meter-long by 20 cm in diameter, were cut from the trunk of a healthy Anadenanthera colubrina (Fabaceae) tree in October 2013 and tied in the understory at 1.5m high in the Rio Doce State Park, Minas Gerais State, Brazil. The logs, exposed in the forest, were each removed after 40, 80 and 120 days and stored individually in a cardboard box in the "Laboratório de Campo do Projeto de Ecologia de Longa Duração (PELD-CNPq)" in the Rio Doce State Park. A total of 94 individuals of T. lineatocolle and 228 of T. megacephala emerged from the A. colubrina logs. This is the first report of a host plant for T. lineatocolle and a new host plant for T. megacephala.

Besouros broqueadores se desenvolvem em árvores vivas e madeira morta, realizando serviços ecológicos como decomposição e regulação de recursos da floresta. Espécies da família Cerambycidae, amplamente distribuídas no mundo, perfuram o caule de árvores e madeira morta em áreas nativas e cultivadas. O objetivo é relatar a primeira planta hospedeira de Thoracibidion lineatocolle (Thomson, 1865) (Coleoptera: Cerambycidae) e uma nova planta hospedeira para Temnopis megacephala (Germar, 1824) (Coleoptera: Cerambycidae) no bioma da Mata Atlântica brasileira. Três toras, com um metro de comprimento por 20 cm de diâmetro, foram cortadas de uma árvore sadia de Anadenanthera colubrina (Fabaceae) em outubro de 2013 e amarradas no sub-bosque a 1,5m de altura no Parque Estadual do Rio Doce, estado de Minas Gerais, Brasil. As toras, expostas na floresta, foram removidas, cada uma, após 40, 80 e 120 dias e armazenadas, individualmente, em caixas de papelão no “Laboratório de Campo do Projeto de Ecologia de Longa Duração (PELD-CNPq)” no Parque Estadual do Rio Doce. Um total de 94 indivíduos de T. lineatocolle e 228 de T. megacephala emergiu das toras de A. colubrina. Esse é o primeiro registro de uma planta hospedeira para T. lineatocolle e o de uma nova planta hospedeira para T. megacephala.

Anadenanthera colubrina (Fabaceae) logs in the Atlantic Forest biome: first host plant for Thoracibidion lineatocolle (Col.: Cerambycidae) and a new host for Temnopis megacephala (Col.: Cerambycidae)

Abstract Wood-boring beetles develop in live trees and dead wood, performing ecological services such as decomposition and regulation of forest resources. Species of the Cerambycidae family, widely distributed in the world, bore into the trunks of trees and dead wood in native and cultivated areas. The objective is to report the first host plant for Thoracibidion lineatocolle (Thomson, 1865) (Coleoptera: Cerambycidae) and a new host plant for Temnopis megacephala (Germar, 1824) (Coleoptera: Cerambycidae) in the Brazilian Atlantic Forest biome. Three logs, with one-meter-long by 20 cm in diameter, were cut from the trunk of a healthy Anadenanthera colubrina (Fabaceae) tree in October 2013 and tied in the understory at 1.5m high in the Rio Doce State Park, Minas Gerais State, Brazil. The logs, exposed in the forest, were each removed after 40, 80 and 120 days and stored individually in a cardboard box in the Laboratório de Campo do Projeto de Ecologia de Longa Duração (PELD-CNPq) in the Rio Doce State Park. A total of 94 individuals of T. lineatocolle and 228 of T. megacephala emerged from the A. colubrina logs. This is the first report of a host plant for T. lineatocolle and a new host plant for T. megacephala.

Resumo Besouros broqueadores se desenvolvem em árvores vivas e madeira morta, realizando serviços ecológicos como decomposição e regulação de recursos da floresta. Espécies da família Cerambycidae, amplamente distribuídas no mundo, perfuram o caule de árvores e madeira morta em áreas nativas e cultivadas. O objetivo é relatar a primeira planta hospedeira de Thoracibidion lineatocolle (Thomson, 1865) (Coleoptera: Cerambycidae) e uma nova planta hospedeira para Temnopis megacephala (Germar, 1824) (Coleoptera: Cerambycidae) no bioma da Mata Atlântica brasileira. Três toras, com um metro de comprimento por 20 cm de diâmetro, foram cortadas de uma árvore sadia de Anadenanthera colubrina (Fabaceae) em outubro de 2013 e amarradas no sub-bosque a 1,5m de altura no Parque Estadual do Rio Doce, estado de Minas Gerais, Brasil. As toras, expostas na floresta, foram removidas, cada uma, após 40, 80 e 120 dias e armazenadas, individualmente, em caixas de papelão no Laboratório de Campo do Projeto de Ecologia de Longa Duração (PELD-CNPq) no Parque Estadual do Rio Doce. Um total de 94 indivíduos de T. lineatocolle e 228 de T. megacephala emergiu das toras de A. colubrina. Esse é o primeiro registro de uma planta hospedeira para T. lineatocolle e o de uma nova planta hospedeira para T. megacephala.

Anadenanthera colubrina (Fabaceae) logs in the Atlantic Forest biome: first host plant for Thoracibidion lineatocolle (Col: Cerambycidae) and a new host for Temnopis megacephala (Col: Cerambycidae) / Troncos de Anadenanthera colubrina (Fabaceae) no bioma da Mata Atlântica: primeira planta hospedeira de Thoracibidion lineatocolle (Col: Cerambycidae) e uma nova planta hospedeira para Temnopis megacephala (Col: Cerambycidae)

Wood-boring beetles develop in live trees and dead wood, performing ecological services such as decomposition and regulation of forest resources. Species of the Cerambycidae family, widely distributed in the world, bore into the trunks of trees and dead wood in native and cultivated areas. The objective is to report the first host plant for Thoracibidion lineatocolle (Thomson, 1865) (Coleoptera: Cerambycidae) and a new host plant for Temnopis megacephala (Germar, 1824) (Coleoptera: Cerambycidae) in the Brazilian Atlantic Forest biome. Three logs, with one-meter-long by 20 cm in diameter, were cut from the trunk of a healthy Anadenanthera colubrina (Fabaceae) tree in October 2013 and tied in the understory at 1.5m high in the Rio Doce State Park, Minas Gerais State, Brazil. The logs, exposed in the forest, were each removed after 40, 80 and 120 days and stored individually in a cardboard box in the "Laboratório de Campo do Projeto de Ecologia de Longa Duração (PELD-CNPq)" in the Rio Doce State Park. A total of 94 individuals of T. lineatocolle and 228 of T. megacephala emerged from the A. colubrina logs. This is the first report of a host plant for T. lineatocolle and a new host plant for T. megacephala.

Besouros broqueadores se desenvolvem em árvores vivas e madeira morta, realizando serviços ecológicos como decomposição e regulação de recursos da floresta. Espécies da família Cerambycidae, amplamente distribuídas no mundo, perfuram o caule de árvores e madeira morta em áreas nativas e cultivadas. O objetivo é relatar a primeira planta hospedeira de Thoracibidion lineatocolle (Thomson, 1865) (Coleoptera: Cerambycidae) e uma nova planta hospedeira para Temnopis megacephala (Germar, 1824) (Coleoptera: Cerambycidae) no bioma da Mata Atlântica brasileira. Três toras, com um metro de comprimento por 20 cm de diâmetro, foram cortadas de uma árvore sadia de Anadenanthera colubrina (Fabaceae) em outubro de 2013 e amarradas no sub-bosque a 1,5m de altura no Parque Estadual do Rio Doce, estado de Minas Gerais, Brasil. As toras, expostas na floresta, foram removidas, cada uma, após 40, 80 e 120 dias e armazenadas, individualmente, em caixas de papelão no "Laboratório de Campo do Projeto de Ecologia de Longa Duração (PELD-CNPq)" no Parque Estadual do Rio Doce. Um total de 94 indivíduos de T. lineatocolle e 228 de T. megacephala emergiu das toras de A. colubrina. Esse é o primeiro registro de uma planta hospedeira para T. lineatocolle e o de uma nova planta hospedeira para T. megacephala.

Using drones and ROV to assess the vulnerability of marine megafauna to the Fundão tailings dam collapse.

The ecology and life history of marine megafauna can answer the ecological importance of a region. This study assesses and monitors the abundance and home range of sea turtles, seabirds, marine mammals and the association with coastal microhabitats in potentially impacted areas at the Rio Doce river mouth, Comboios, and Piraquê-açu river mouth after the collapse of the Fundão dam. Remotely Operated Vehicles (ROV) and UAVs (Unmanned Aerial Vehicles, or drones) were used for megafauna species identification, behavior, population data, habitat characterization, and monitoring of environmental protection areas. The species Sotalia guianensis and Pontoporia blainvillei were the most recorded cetaceans, and the main observed behavior was feeding. Guiana dolphin (S. guianensis) occurs in greater density in the Rio Doce river mouth region, resulting in more than 10 sightings/km2, while franciscana (P. blainvillei) were the most concentrated Comboios area. The seabirds (all species) had up to 15 sightings/km2 at the Rio Doce river mouth, the highest density among sampled areas. The green turtle (Chelonia mydas) was the most frequently recorded, followed by the leatherback turtle (Dermochelys coriacea). The green turtle occurred at a higher concentration at the Piraquê-Açu river mouth (above 6 sightings/km2). The sites closest to Rio Doce river mouth and Comboios predominantly showed mud bottoms, while those at Piraquê-Açu mouth were mostly reef structures. The estuarine areas showed greater importance for megafauna than marine areas.

The ichthyofauna of a poorly known area in the middle-southern Espinhaço mountain range, state of Minas Gerais, Brazil: diagnostics and identification keys.

Knowledge about the taxonomy and fish composition from the upper rio Paraúna (rio São Francisco basin) and upper rio Santo Antônio (rio Doce basin) in the middle portion of the Southern Espinhaço mountain range, state of Minas Gerais, Brazil is still incipient. Only few studies focusing on ichthyofaunistic diagnostic and species descriptions in the lower stretches of the rio Santo Antônio are available. Herein the aim was to provide a species list of the freshwater ichthyofauna from the headwaters of both basins in such region, and to verify the occurrence of threatened, exotic, and potentially new species. Sixty species were registered, with 34 associated to the upper rio Paraúna, and 40 to the upper rio Santo Antônio. Two species are included in some threatened category, three are exotics, and 14 represent potentially new species. An identification key of the fish species recorded in the area is also provided.

Hydraulic and auto-depurative characteristics of the Gualaxo do Norte River after the Fundão dam rupture.

The hydraulic characteristics of the Gualaxo do Norte River (RGN), a tributary of the upper Rio Doce basin, were affected in November 2015 by the rupture of the iron ore tailings dam at Fundão, in Bento Rodrigues, Mariana, Minas Gerais. We analyzed two sections of the RGN, located upstream and downstream of the Fundão dam. Measurements were taken at 11 stations along the main river in distinct seasonal periods, including river depth, river width, velocity, and flow. We also calculated the deoxygenation coefficient (K1) and the reaeration coefficient (K2) and collected elaborate bathymetric profiles of the sections. Anthropogenic interference influenced the river's hydraulic characteristics mainly in relation to the depth. In upstream sections, the changes are believed to be due to mining activities at the head of the river, while downstream effects were due to the introduction of iron ore tailings coming from the rupture of the Fundão dam. Despite these influences, deoxygenation coefficient values were typical for clean water, and the reaeration coefficient findings show that the RGN is efficient at biological degradation of the organic matter even receiving untreated domestic sewage from riparian communities. With the results obtained in this work, we seek to replicate a source of information about the current state of the region and to contribute information to future river planning, control, and restoration projects.

Drastic reduction of the functional diversity of native ichthyofauna in a Neotropical lake following invasion by piscivorous fishes

Biological invasions are leading several species to extinction and are projected as a main driver of biodiversity changes in lakes for this century. However, the knowledge of their impacts on the Neotropical ichthyofauna over time remains largely incipient, especially when considering the functional diversity of native communities. Here we aim to identify the effects of non-native species, especially the non-native piscivorous Cichla kelberi and Pygocentrus nattereri, on the functional diversity of the native ichthyofauna of the Carioca Lake, Middle Rio Doce basin, state of Minas Gerais. Using fish occurrence data for eight years from 1983 to 2010 combined with an ecomorphological-trait analysis, we found that while the native species richness dropped to 56%, the functional richness is only 27% of that found before introductions. In other words, more than species, the ichthyofauna suffered an impressive decline in the range of functional traits, which can further have severe impacts on ecological processes within that system. When considering all the components of the current ichthyofauna (native and non-native species), neither taxonomic nor functional richness have changed over time. However, even keeping biodiversity levels, non-native species are not able to fully compensate for the extinct native ones in terms of functions.(AU)

Invasões biológicas vêm levando várias espécies à extinção, sendo projetado como o principal causador de mudanças na biodiversidade em lagos neste século. Entretanto, o conhecimento dos impactos sobre a ictiofauna Neotropical ao longo do tempo permanece bastante incipiente, especialmente quando se considera a diversidade funcional de comunidades nativas. Neste estudo, nós procuramos identificar os efeitos das espécies não nativas, especialmente os piscívoros não nativos Cichla kelberi and Pygocentrus nattereri, sobre a diversidade funcional da ictiofauna da Lagoa Carioca, bacia do médio rio Doce, Minas Gerais. Utilizando dados de ocorrência de oito anos entre 1983 e 2010, combinados a uma análise de atributos ecomorfológicos, observamos que a riqueza de espécies decaiu a 56%, enquanto a riqueza funcional é de apenas 27% da encontrada antes das introduções. Ou seja, mais do que espécies, a ictiofauna sofreu um declínio significativo na amplitude de atributos funcionais, o que pode levar a impactos severos em processos ecológicos neste sistema. Ao considerar todos os componentes da ictiofauna atual (espécies nativas e não nativas), as métricas de riqueza não sofreram alterações ao longo do tempo. Entretanto, mesmo mantendo os níveis de biodiversidade, espécies não nativas não são capazes de compensar totalmente as espécies nativas extintas em termos funcionais.(AU)

Contamination and oxidative stress biomarkers in estuarine fish following a mine tailing disaster.

BACKGROUND: The Rio Doce estuary, in Brazil, was impacted by the deposition of iron mine tailings, caused by the collapse of a dam in 2015. Based on published baseline datasets, the estuary has been experiencing chronic trace metal contamination effects since 2017, with potential bioaccumulation in fishes and human health risks. As metal and metalloid concentrations in aquatic ecosystems pose severe threats to the aquatic biota, we hypothesized that the trace metals in estuarine sediments nearly two years after the disaster would lead to bioaccumulation in demersal fishes and result in the biosynthesis of metal-responsive proteins. METHODS: We measured As, Cd, Cr, Cu, Fe, Mn, Pb, Se and Zn concentrations in sediment samples in August 2017 and compared to published baseline levels. Also, trace metals (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, Se and Zn) and protein (metallothionein and reduced glutathione) concentrations were quantified in the liver and muscle tissues of five fish species (Cathorops spixii, Genidens genidens, Eugerres brasilianus, Diapterus rhombeus and Mugil sp.) from the estuary, commonly used as food sources by local populations. RESULTS: Our results revealed high trace metal concentrations in estuarine sediments, when compared to published baseline values for the same estuary. The demersal fish species C. spixii and G. genidens had the highest concentrations of As, Cr, Mn, Hg, and Se in both, hepatic and muscle, tissues. Trace metal bioaccumulation in fish was correlated with the biosynthesis of metallothionein and reduced glutathione in both, liver and muscle, tissues, suggesting active physiological responses to contamination sources. The trace metal concentrations determined in fish tissues were also present in the estuarine sediments at the time of this study. Some elements had concentrations above the maximum permissible limits for human consumption in fish muscles (e.g., As, Cr, Mn, Se and Zn), suggesting potential human health risks that require further studies. Our study supports the high biogeochemical mobility of toxic elements between sediments and the bottom-dwelling biota in estuarine ecosystems.

Three new species of Aricidea (Acmira) (Annelida: Paraonidae) from the Continental Shelf of Eastern Brazil, Southwestern Atlantic.

Three new species of the Paraonidae genus Aricidea (Acmira) are described from the Southwestern Atlantic, East Brazilian Continental Shelf (from depths between 11 and 44 m) in the Espírito Santo Basin. The species Aricidea (Acmira) filamentosa sp. nov., Aricidea (Acmira) pearti sp. nov. and Aricidea (Acmira) bbkingi sp. nov. are clearly different from all known species in the genus through its chaetal morphology, number of branchiate chaetigers and shape of antenna. These three species were found in only a few sampling stations, geographically and bathymetrically restricted within a much wider sampled area.

Rio Doce Acoustic Surveys of Fish Biomass and Aquatic Habitat.

Following the failure of the Fundão mine tailings dam in Brazil, approximately 32 million cubic meters of Fe ore tailings were released into the downstream riverine system. The postevent monitoring surveys implemented the use of noninvasive acoustic methods to improve the understanding of the fish biomass distribution patterns and aquatic habitat condition of the impacted reaches of the Rio Gualaxo do Norte, Rio do Carmo, and Rio Doce. The primary focus of the program was to collect hydroacoustic measurements of fish biomass, which was accompanied by sonar imaging of aquatic habitats using high-resolution side scan and downward imaging sonar at each site visited. The biannual surveys began in April 2017 and were fundamentally a multiple control-impact design because before data (prior to the dam failure event) were not available. Up to 22 sites were visited for each survey, including reservoir and river sites. Results indicate similar levels of instream habitat between control and impact river and reservoir sites. Average volumetric biomass was not significantly different between impact sites and their corresponding controls in the August 2018 survey (latest to date). Preliminary temporal analysis of the biomass data set collected indicates that either stable or increasing levels of biomass are detected at tailings impacted sites within the Rio Doce. Integr Environ Assess Manag 2020;16:615-621. © 2020 Hydrobiology QLD Pty Ltd. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Após o rompimento da barragem de rejeitos da mina do Fundão no Brasil, cerca de 32 milhões de metros cúbicos de rejeitos de minério de Fe foram libertados no sistema fluvial a jusante. Monitoramentos pós-evento foram implementados com a utilização de métodos acústicos não invasivos visando ampliar a compreensão dos padrões de distribuição da biomassa de peixes e condições dos habitat aquáticos em trechos impactados do Rio Gualaxo do Norte, Rio do Carmo e Rio Doce. A aquisição de medições hidroacústicas sobre a biomassa de peixes foi o foco principal do programa, seguido pela obtenção de imagens dos habitats aquáticos através da utilização de um sonar de varredura lateral de alta resolução e um sonar de imagem vertical, em cada local visitado. Os levantamentos de campo semestrais tiveram início em Abril de 2017 e seu design amostral foi baseados na concepção "trechos controle - trechos impactados" uma vez que não existem dados disponíveis para o período anterior ao evento (rompimento da barragem). Em cada levantamento foram visitados até 22 pontos de amostragem, incluindo vários reservatórios e rios. Os resultados indicaram níveis de habitat similares entre os pontos controle e impacto, de rios e reservatórios. No monitoramento mais recente (Agosto/2018) a biomassa volumétrica média não foi significativamente diferente entre os locais de impacto e os seus correspondentes pontos controles. A análise temporal preliminar do conjunto de dados sobre a biomassa indicou níveis estáveis ou crescentes deste parâmetro nos locais impactados pelos rejeitos, no Rio Doce. Integr Environ Assess Manag 2020;16:615-621.

Civil Society and Social Mobilizations in the Context of the Rio Doce Socioenvironmental Disaster.

To explain how social movements and organizations changed in the context of the Rio Doce, Brazil socioenvironmental disaster, this article identifies a process of organizational innovation. The research is based on documental data and interviews with activists over the 3 y of the disaster. The main argument is that organizational innovation consists of changes in organizational forms and repertoires of collective action, based on existing organizational models and tactics. On the one hand, the innovation occurred through the territorialization of novel organizational forms, intermediated by social movements that act as incubators. On the other hand, it consisted of the combination among extrainstitutional, institutional, and multiscalar repertoires and in the innovation in tactics and performances. Mechanisms of adaptation, imitation, and negotiated diffusion are identified which operated in this innovation process. It is argued that the organizational innovation of social movements was propelled by political constraints of disaster governance, which pushed them to innovation, in addition to the role of preexisting organizations. Integr Environ Assess Manag 2020;16:681-690. © 2020 SETAC.

Para explicar como os movimentos sociais e organizações da sociedade civil mudaram no contexto do desastre socioambiental do Rio Doce, este artigo identificou um processo de inovação organizacional. A pesquisa é baseada em dados documentais e entrevistas com ativistas ao longo dos três anos do desastre. O argumento principal é que a inovação organizacional consiste em mudanças nas formas organizacionais e repertórios da ação coletiva, com base nos modelos organizacionais e táticas disponíveis. Por um lado, a inovação ocorreu através da territorialização de novas formas organizacionais, intermediadas por movimentos sociais que atuaram como incubadoras. Por outro, consistiu na combinação entre repertórios extrainstitucionais, institucionais e multiescalares e na inovação nas táticas e performances. São identificados os mecanismos de adaptação, imitação e difusão negociada que operaram nesse processo de inovação. Argumenta-se que a inovação organizacional dos movimentos sociais foi impulsionada por constrangimentos políticos da governança do desastre que os levaram à inovação, além do papel das organizações pré-existentes. Integr Environ Assess Manag 2020;16:681-690.

Geochemical evaluation of bottom sediments affected by historic mining and the rupture of the Fundão dam, Brazil.

The rupture of the Fundão dam released about 39 million m3 of tailings into the Rio Doce/Brazil. The sediment load increase in the affected rivers has become a concern. As such, this article provides recent information about the region. In addition, based on past studies in the region, it shows the magnitude and dynamics of the environmental impacts caused by the rupture of the dam on the bottom sediments. Sediment samples in different seasonal periods were collected at eleven sampling stations located along the Gualaxo do Norte River, the first tributary of the Rio Doce affected by the environmental disaster. These sediments underwent physical, chemical, and granulometric analyses for their organic, metal, and semimetal content. The contamination factor and the enrichment factor of the samples also were calculated. To evaluate the anthropogenic contributions to sediment metal concentrations, reference values (regional background values) for the Gualaxo do Norte River were used. The results indicate that, in the sampling stations not affected by the disaster, the concentrations of the metals and semimetals reflect the geology of the Quadrilátero Ferrífero. However, in the area affected by the environmental disaster, there were changes in the chemical and physical properties of the bottom sediment, mainly in the concentrations of iron, organic matter, and fine sediment fractions. This was reflected in the contamination factors and enrichment factors calculated for the sediments of the sampling stations. Iron and manganese concentrations in sediments are much higher than other rivers in the world that are unaffected by mining activities. The observed changes in the bottom sediments of the river suggest a need for constant monitoring of the iron because the iron oxide minerals present in silt and clay have a high adsorption capacity. In the long term, these factors may contribute to the decrease of the quality of these sediments and consequently of the waters and biota present in these environments.

Land use dynamics and future scenarios of the Rio Doce State Park buffer zone, Minas Gerais, Brazil.

It is necessary to understand the importance of landscapes that comprise the environment across a broad range of time and space and that each part of these landscapes responds to changes in environmental factors and land use. This study employs a multiscale modeling approach in the Rio Doce State Park (PERD), located in Minas Gerais, Brazil, based on a previous study on land use change in this region over the last 30 years (1985-2015), with an aim of predicting possible scenarios for the next 15 years (2015-2030). The results indicate that the municipalities and buffer zones within the PERD will suffer from increased human disturbance in all four land use types present in the region (Urban, Agriculture, Pasture, and Forestry). Correspondingly, areas of natural environment (Forest and Water) will shrink due to an increase in forest fragmentation, causing the loss of permanent ecological reserves, thereby endangering the biodiversity of these areas. Cooperation between the local community and private companies is therefore necessary to improve regional environmental conservation, encourage advanced sustainable development, and improve the quality of life for residents within each municipality near the State Park.