The organisms of the infraorder Nepomorpha (Heteroptera) present complex habitat requirements in ... more The organisms of the infraorder Nepomorpha (Heteroptera) present complex habitat requirements in headwater streams, usually being related to local substrate conditions. Therefore, in this study, we evaluated how the diversity of Nepomorpha responded to a wide gradient of habitat and ecological conditions. We tested two hypotheses: (1) local substrate composition is the most important factor determining the diversity of Nepomorpha compared to other physical habitat metrics, (2) Nepomorpha assemblage diversity respond more readily to anthropogenic disturbances at local scale. Our results did not corroborate the first hypothesis, and showed that the assemblage diversity was mostly related to water quality and geomorphology, indicating that substrate requirements are not the only important driver. Our second hypothesis was partially corroborated, as all diversity metrics presented significant correlation with human disturbances at both local and catchment spatial scales. These results show that Nepomorpha assemblages have high potential use as ecological indicators, which should be better explored in future biomonitoring studies of anthropogenic changes.
Excessive fine sediment (particles <2 mm) deposition in freshwater systems is a pervasive stresso... more Excessive fine sediment (particles <2 mm) deposition in freshwater systems is a pervasive stressor worldwide. However, understanding of ecological response to excess fine sediment in river systems at the global scale is limited. Here, we aim to address whether there is a consistent response to increasing levels of deposited fine sediment by freshwater invertebrates across multiple geographic regions (Australia, Brazil, New Zealand and the UK). Results indicate ecological responses are not globally consistent
Ecossistemas aquáticos continentais sofrem influência direta de pressões antrópicas que podem ser... more Ecossistemas aquáticos continentais sofrem influência direta de pressões antrópicas que podem ser quantificadas através do mapeamento do uso e cobertura do solo. O objetivo deste estudo foi avaliar a relação entre o uso e cobertura do solo e a qualidade de água em uma bacia hidrográfica legalmente protegida: a bacia do rio Pandeiros, Minas Gerais. O levantamento de qualidade de água foi realizado em 40 sítios de amostragem balanceada e aleatoriamente distribuídos. Através de imagens de satélite foi avaliado o uso e cobertura do solo em três escalas espaciais: sub-bacia, ripário e local. Os resultados mostraram que a bacia possui em média de 85%-95% de cobertura vegetal íntegra em todas as escalas espaciais avaliadas, e que os parâmetros de qualidade de água estão dentro dos limites de classe 1, segundo a resolução Conama 357/2005. A correlação entre as classes de uso e cobertura do solo e variáveis de qualidade de água foram baixas em todas as escalas avaliadas, e acredita-se que is...
A caracterização de bacias hidrográficas e o desenvolvimento de ferramentas de diagnóstico de qua... more A caracterização de bacias hidrográficas e o desenvolvimento de ferramentas de diagnóstico de qualidade ambiental para subsidiar o manejo sustentável de recursos hídricos requerem abordagens interdisciplinares. O objetivo deste estudo foi integrar métricas ecológicas e geográficas para diagnosticar qualidade de água na bacia do rio das Velhas, afluente do rio São Francisco (Minas Gerais, Brasil). Foram utilizadas as características da composição e estrutura de comunidades de bioindicadores bentônicos coletados em 19 diferentes afluentes na bacia do rio das Velhas. As informações geográficas foram adquiridas para cada uma das sub-bacias de drenagem de sítio amostral. A densidade populacional urbana e rural, a infraestrutura sanitária e o uso e cobertura da terra foram sintetizados através de uma análise de componentes principais (PCA). As associações entre as métricas ecológicas e geográficas foram analisadas através de regressões lineares, utilizando os três eixos mais representativ...
Distributional congruence among aquatic plants, invertebrates and fishes within the río Paraguay ... more Distributional congruence among aquatic plants, invertebrates and fishes within the río Paraguay basin, Paraguay Interciencia, vol. 29, núm. 4, abril, 2004, pp. 199-206
Invasive bivalves often act as ecosystem engineers, generally causing physical alterations in the... more Invasive bivalves often act as ecosystem engineers, generally causing physical alterations in the ecosystems in which they establish themselves. However, the effects of these physical alterations over benthic macroinvertebrate communities’ structure are less clear. The objective of this study was to characterize the ecological effects of the invasive bivalves Corbicula fluminea and Limnoperna fortunei on the structure of benthic macroinvertebrate communities in neo-tropical reservoirs. Three hypotheses were tested: (1) invasive bivalves act as facilitator species to other benthic macroinvertebrates, resulting in communities with higher number of species, abundance and diversity; (2) invasive bivalves change the taxonomic composition of benthic macroinvertebrate communities; (3) invasive bivalves increase the complexity of benthic macroinvertebrate communities. For that it was used data from 160 sampling sites from four reservoirs. We sampled sites once in each area, during the dry s...
In this study the regulation service was evaluated provided by the maintenance of the riparian zo... more In this study the regulation service was evaluated provided by the maintenance of the riparian zone for the conservation of water courses in the hydrographic basin of a hydroelectric project. This study aims to identify the variables that contribute the most to the ecosystem service of erosion and siltation control in the hydrographic basin of the Nova Ponte Hydroelectric Power Plant (NPHP), Araguari river basin, MG. Were analyzed types of land use and occupation as well a physical habitat metrics in years of regular average rainfall and one with rainfall. Among these variables, presence of native vegetation at riparian zone and flow characteristics were the most important related to the ecosystem service of erosion and sedimentation control in the two sample periods (2009 and 2013). The results obtained corroborate the importance of the conservation of the riparian zone of headwaters for maintenance of the ecosystem service of erosion and sedimentation control, besides contributing...
The aim of this study was to inventory the diversity of benthic macroinvertebrates of the reservo... more The aim of this study was to inventory the diversity of benthic macroinvertebrates of the reservoir of the Peti Environmental Station in Minas Gerais State through the evaluation of these communities in space and temporal scales during the rainy and dry periods from June - 2002 up to June - 2004. The Peti reservoir has almost 50 years and is used for hydropower generation. The benthic macroinvertebrates are an important tool for the evaluation of water quality and environment monitoring through inventories of diversity and data on community structure. A total of 16 taxa was found and the most abundant groups were Chaoboridae (47,51 %), the Chironomidae genera Coelotanypus (15,1%) and Chironomus (2,77%), Bivalvia (19,11%) and Oligochaeta (9,54%). There were no signifi cant variations (R = 0,1927; p >0,05) for the biotic data among the sampling stations during the studied periods. The evaluation of the distribution and structure of the benthic community showed that the quality of t...
Urban land uses such as deforestation, mining, agriculture, logging and road construction, can ca... more Urban land uses such as deforestation, mining, agriculture, logging and road construction, can cause stream sedimentation, modifying the morphology and depth of the river channel and diminishing the availability of physical habitats. Habitat requirements of benthic macroinvertebrates must be considered in a streamflow management strategy to maintain the biotic integrity. The aim of this study was to develop a benthic macroinvertebrate habitat suitability criteria based on velocity, depth and substrate type in a silted river and in three reference rivers, and to evaluate if the diversity and the community structure would differ between them. Three reference rivers from the das Velhas River basin were chosen (Cipó, Curimataí and Pardo Grande) in addition to a stretch at the main channel, which is severely damaged by urbanization and mining activities. Samplings were performed during the dry and rainy seasons along 500 meters in each river. In each sampling period, 25 sediment samples ...
In the process of colonizing sediment benthic macroinvertebrates carry out bioturbation promoting... more In the process of colonizing sediment benthic macroinvertebrates carry out bioturbation promoting the transport of solutes and particles at the sediment-water interface. The objective of the present study was to evaluate the influence of Chironomus larva, by way of bioturbation, on the flow of dissolved oxygen, carbon dioxide, phosphate, ammonia and nitrate at the sediment-water interface of the Ibirite reservoir (Brazil). For this, we recreated microcosms in 24 plexiglass cylinders (“core”) (20 cm long, 4.5 cm inner diameter) containing the contents for the sediment-water interface of the Ibirite reservoir, being that 12 cores had sandy sediment and 12 had muddy sediment. The cores were subjected to different treatments in triplicate: controls (without Chironomus larvae) and incubated cores with 2, 4 and 6 Chironomus larvae (1250, 2500, 3750 ind.m). Significant correlations were observed between the fluxes of O2, PO4, NH4 and NO3 and the density of Chironomus (Pearson, p<0.05). ...
Resumen en: The Rapid Assessment Program (RAP) constitutes a powerful tool used to select importa... more Resumen en: The Rapid Assessment Program (RAP) constitutes a powerful tool used to select important areas for the conservation of biodiversity. The relationships b...
In many countries of the Global South, aquatic ecosystems such as streams, rivers, lakes, and wet... more In many countries of the Global South, aquatic ecosystems such as streams, rivers, lakes, and wetlands are severely impacted by several simultaneous environmental stressors, associated with accelerated urban development, and extreme climate. However, this problem receives little attention. Applying a DPSIR approach (Drivers, Pressures, State, Impacts, Responses), we analyzed the environmental impacts and their effects on urban hydrosystems (including stagnant waters), and suggest possible solutions from a series of case studies worldwide. We find that rivers in the Global South, with their distinctive geographical and socio-political setting, display significant differences from the Urban Stream Syndrome described so far in temperate zones. We introduce the term of ‘Southern Urban Hydrosystem Syndrome’ for the biophysical problems as well as the social interactions, including the perception of water bodies by the urbanites, the interactions of actors (e.g., top-down, bottom-up), and...
Dams are a major threat to aquatic biological diversity. By altering the natural flow of rivers, ... more Dams are a major threat to aquatic biological diversity. By altering the natural flow of rivers, dams modify fluvial habitats, making them unsuitable for the growth and reproduction of many aquatic species. The aim of this study was to evaluate the effects of a reduced flow reach (RFR) on benthic macroinvertebrate communities. Benthic macroinvertebrates were collected at six sites downstream of the Amador Aguiar Power Plant I before (lotic phase) and after (semi-lentic phase) Araguari River mean flow was reduced from 346 to 7 m³.s-1. Changes in macroinvertebrates richness, diversity and total biomass were not observed. Ablabesmyia, Tanytarsus (Chironomidae, Diptera), Leptoceridae and Polycentropodidae (Trichoptera) densities significantly increased the first year after flow reduction and the construction of spillways (t-test; p < 0.05). An analysis of similarity (ANOSIM) showed statistical differences in taxonomical composition despite considerable overlap in communities between ...
The organisms of the infraorder Nepomorpha (Heteroptera) present complex habitat requirements in ... more The organisms of the infraorder Nepomorpha (Heteroptera) present complex habitat requirements in headwater streams, usually being related to local substrate conditions. Therefore, in this study, we evaluated how the diversity of Nepomorpha responded to a wide gradient of habitat and ecological conditions. We tested two hypotheses: (1) local substrate composition is the most important factor determining the diversity of Nepomorpha compared to other physical habitat metrics, (2) Nepomorpha assemblage diversity respond more readily to anthropogenic disturbances at local scale. Our results did not corroborate the first hypothesis, and showed that the assemblage diversity was mostly related to water quality and geomorphology, indicating that substrate requirements are not the only important driver. Our second hypothesis was partially corroborated, as all diversity metrics presented significant correlation with human disturbances at both local and catchment spatial scales. These results show that Nepomorpha assemblages have high potential use as ecological indicators, which should be better explored in future biomonitoring studies of anthropogenic changes.
Excessive fine sediment (particles <2 mm) deposition in freshwater systems is a pervasive stresso... more Excessive fine sediment (particles <2 mm) deposition in freshwater systems is a pervasive stressor worldwide. However, understanding of ecological response to excess fine sediment in river systems at the global scale is limited. Here, we aim to address whether there is a consistent response to increasing levels of deposited fine sediment by freshwater invertebrates across multiple geographic regions (Australia, Brazil, New Zealand and the UK). Results indicate ecological responses are not globally consistent
Ecossistemas aquáticos continentais sofrem influência direta de pressões antrópicas que podem ser... more Ecossistemas aquáticos continentais sofrem influência direta de pressões antrópicas que podem ser quantificadas através do mapeamento do uso e cobertura do solo. O objetivo deste estudo foi avaliar a relação entre o uso e cobertura do solo e a qualidade de água em uma bacia hidrográfica legalmente protegida: a bacia do rio Pandeiros, Minas Gerais. O levantamento de qualidade de água foi realizado em 40 sítios de amostragem balanceada e aleatoriamente distribuídos. Através de imagens de satélite foi avaliado o uso e cobertura do solo em três escalas espaciais: sub-bacia, ripário e local. Os resultados mostraram que a bacia possui em média de 85%-95% de cobertura vegetal íntegra em todas as escalas espaciais avaliadas, e que os parâmetros de qualidade de água estão dentro dos limites de classe 1, segundo a resolução Conama 357/2005. A correlação entre as classes de uso e cobertura do solo e variáveis de qualidade de água foram baixas em todas as escalas avaliadas, e acredita-se que is...
A caracterização de bacias hidrográficas e o desenvolvimento de ferramentas de diagnóstico de qua... more A caracterização de bacias hidrográficas e o desenvolvimento de ferramentas de diagnóstico de qualidade ambiental para subsidiar o manejo sustentável de recursos hídricos requerem abordagens interdisciplinares. O objetivo deste estudo foi integrar métricas ecológicas e geográficas para diagnosticar qualidade de água na bacia do rio das Velhas, afluente do rio São Francisco (Minas Gerais, Brasil). Foram utilizadas as características da composição e estrutura de comunidades de bioindicadores bentônicos coletados em 19 diferentes afluentes na bacia do rio das Velhas. As informações geográficas foram adquiridas para cada uma das sub-bacias de drenagem de sítio amostral. A densidade populacional urbana e rural, a infraestrutura sanitária e o uso e cobertura da terra foram sintetizados através de uma análise de componentes principais (PCA). As associações entre as métricas ecológicas e geográficas foram analisadas através de regressões lineares, utilizando os três eixos mais representativ...
Distributional congruence among aquatic plants, invertebrates and fishes within the río Paraguay ... more Distributional congruence among aquatic plants, invertebrates and fishes within the río Paraguay basin, Paraguay Interciencia, vol. 29, núm. 4, abril, 2004, pp. 199-206
Invasive bivalves often act as ecosystem engineers, generally causing physical alterations in the... more Invasive bivalves often act as ecosystem engineers, generally causing physical alterations in the ecosystems in which they establish themselves. However, the effects of these physical alterations over benthic macroinvertebrate communities’ structure are less clear. The objective of this study was to characterize the ecological effects of the invasive bivalves Corbicula fluminea and Limnoperna fortunei on the structure of benthic macroinvertebrate communities in neo-tropical reservoirs. Three hypotheses were tested: (1) invasive bivalves act as facilitator species to other benthic macroinvertebrates, resulting in communities with higher number of species, abundance and diversity; (2) invasive bivalves change the taxonomic composition of benthic macroinvertebrate communities; (3) invasive bivalves increase the complexity of benthic macroinvertebrate communities. For that it was used data from 160 sampling sites from four reservoirs. We sampled sites once in each area, during the dry s...
In this study the regulation service was evaluated provided by the maintenance of the riparian zo... more In this study the regulation service was evaluated provided by the maintenance of the riparian zone for the conservation of water courses in the hydrographic basin of a hydroelectric project. This study aims to identify the variables that contribute the most to the ecosystem service of erosion and siltation control in the hydrographic basin of the Nova Ponte Hydroelectric Power Plant (NPHP), Araguari river basin, MG. Were analyzed types of land use and occupation as well a physical habitat metrics in years of regular average rainfall and one with rainfall. Among these variables, presence of native vegetation at riparian zone and flow characteristics were the most important related to the ecosystem service of erosion and sedimentation control in the two sample periods (2009 and 2013). The results obtained corroborate the importance of the conservation of the riparian zone of headwaters for maintenance of the ecosystem service of erosion and sedimentation control, besides contributing...
The aim of this study was to inventory the diversity of benthic macroinvertebrates of the reservo... more The aim of this study was to inventory the diversity of benthic macroinvertebrates of the reservoir of the Peti Environmental Station in Minas Gerais State through the evaluation of these communities in space and temporal scales during the rainy and dry periods from June - 2002 up to June - 2004. The Peti reservoir has almost 50 years and is used for hydropower generation. The benthic macroinvertebrates are an important tool for the evaluation of water quality and environment monitoring through inventories of diversity and data on community structure. A total of 16 taxa was found and the most abundant groups were Chaoboridae (47,51 %), the Chironomidae genera Coelotanypus (15,1%) and Chironomus (2,77%), Bivalvia (19,11%) and Oligochaeta (9,54%). There were no signifi cant variations (R = 0,1927; p >0,05) for the biotic data among the sampling stations during the studied periods. The evaluation of the distribution and structure of the benthic community showed that the quality of t...
Urban land uses such as deforestation, mining, agriculture, logging and road construction, can ca... more Urban land uses such as deforestation, mining, agriculture, logging and road construction, can cause stream sedimentation, modifying the morphology and depth of the river channel and diminishing the availability of physical habitats. Habitat requirements of benthic macroinvertebrates must be considered in a streamflow management strategy to maintain the biotic integrity. The aim of this study was to develop a benthic macroinvertebrate habitat suitability criteria based on velocity, depth and substrate type in a silted river and in three reference rivers, and to evaluate if the diversity and the community structure would differ between them. Three reference rivers from the das Velhas River basin were chosen (Cipó, Curimataí and Pardo Grande) in addition to a stretch at the main channel, which is severely damaged by urbanization and mining activities. Samplings were performed during the dry and rainy seasons along 500 meters in each river. In each sampling period, 25 sediment samples ...
In the process of colonizing sediment benthic macroinvertebrates carry out bioturbation promoting... more In the process of colonizing sediment benthic macroinvertebrates carry out bioturbation promoting the transport of solutes and particles at the sediment-water interface. The objective of the present study was to evaluate the influence of Chironomus larva, by way of bioturbation, on the flow of dissolved oxygen, carbon dioxide, phosphate, ammonia and nitrate at the sediment-water interface of the Ibirite reservoir (Brazil). For this, we recreated microcosms in 24 plexiglass cylinders (“core”) (20 cm long, 4.5 cm inner diameter) containing the contents for the sediment-water interface of the Ibirite reservoir, being that 12 cores had sandy sediment and 12 had muddy sediment. The cores were subjected to different treatments in triplicate: controls (without Chironomus larvae) and incubated cores with 2, 4 and 6 Chironomus larvae (1250, 2500, 3750 ind.m). Significant correlations were observed between the fluxes of O2, PO4, NH4 and NO3 and the density of Chironomus (Pearson, p<0.05). ...
Resumen en: The Rapid Assessment Program (RAP) constitutes a powerful tool used to select importa... more Resumen en: The Rapid Assessment Program (RAP) constitutes a powerful tool used to select important areas for the conservation of biodiversity. The relationships b...
In many countries of the Global South, aquatic ecosystems such as streams, rivers, lakes, and wet... more In many countries of the Global South, aquatic ecosystems such as streams, rivers, lakes, and wetlands are severely impacted by several simultaneous environmental stressors, associated with accelerated urban development, and extreme climate. However, this problem receives little attention. Applying a DPSIR approach (Drivers, Pressures, State, Impacts, Responses), we analyzed the environmental impacts and their effects on urban hydrosystems (including stagnant waters), and suggest possible solutions from a series of case studies worldwide. We find that rivers in the Global South, with their distinctive geographical and socio-political setting, display significant differences from the Urban Stream Syndrome described so far in temperate zones. We introduce the term of ‘Southern Urban Hydrosystem Syndrome’ for the biophysical problems as well as the social interactions, including the perception of water bodies by the urbanites, the interactions of actors (e.g., top-down, bottom-up), and...
Dams are a major threat to aquatic biological diversity. By altering the natural flow of rivers, ... more Dams are a major threat to aquatic biological diversity. By altering the natural flow of rivers, dams modify fluvial habitats, making them unsuitable for the growth and reproduction of many aquatic species. The aim of this study was to evaluate the effects of a reduced flow reach (RFR) on benthic macroinvertebrate communities. Benthic macroinvertebrates were collected at six sites downstream of the Amador Aguiar Power Plant I before (lotic phase) and after (semi-lentic phase) Araguari River mean flow was reduced from 346 to 7 m³.s-1. Changes in macroinvertebrates richness, diversity and total biomass were not observed. Ablabesmyia, Tanytarsus (Chironomidae, Diptera), Leptoceridae and Polycentropodidae (Trichoptera) densities significantly increased the first year after flow reduction and the construction of spillways (t-test; p < 0.05). An analysis of similarity (ANOSIM) showed statistical differences in taxonomical composition despite considerable overlap in communities between ...
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