scholarly journals The Amazon River microbiome, a story of humic carbon.

2021 ◽  
Author(s):  
Francois-Etienne Sylvain ◽  
Sidki Bouslama ◽  
Aleicia Holland ◽  
Nicolas Leroux ◽  
Pierre-Luc Mercier ◽  
...  
Keyword(s):  
Amazon Basin ◽  
Lignin Degradation ◽  
Transcriptional Activity ◽  
Meta Analysis ◽  
Degradation Process ◽  
Amazon River ◽  
Potential Implication ◽  
Water Types ◽  
Sampling Campaign ◽  
Doc Concentration

The Amazon River basin sustains dramatic hydrochemical gradients defined by three water types: white, clear and black waters. Black waters contain important loads of allochthonous humic dissolved organic carbon (DOC), mostly coming from bacteria-mediated lignin degradation, a process that remains understudied. Here, we identified the main bacterial taxa and functions associated with contrasting Amazonian water types, and shed light on their potential implication in the lignin degradation process. We performed an extensive field bacterioplankton sampling campaign from the three Amazonian water types, and combined our observations to a meta-analysis of 90 Amazonian basin shotgun metagenomes used to build a tailored functional inference database. We showed that the overall quality of DOC is a major driver of bacterioplankton structure, transcriptional activity and functional repertory. We also showed that among the taxa mostly associated to differences between water types, Polynucleobacter sinensis particularly stood out, as its abundance and transcriptional activity was strongly correlated to black water environments, and specially to humic DOC concentration. Screening the reference genome of this bacteria, we found genes coding for enzymes implicated in all the main lignin degradation steps, suggesting that this bacteria may play key roles in the carbon cycle processes within the Amazon basin.

A global meta-analysis reveals a significant offset in δ2H between plant water and its sources

2021 ◽  
Author(s):  
Javier de la Casa ◽  
Adrià Barbeta ◽  
Asun Rodriguez-Uña ◽  
Lisa Wingate ◽  
Jérôme Ogeé ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Soil Water ◽  
Meta Analysis ◽  
Water Evaporation ◽  
Source Water ◽  
Plant Water ◽  
Water Line ◽  
Plant Source ◽  
Sampling Campaign ◽  
The Mean

<p> </p><p>Long-standing ecological theory establishes that the isotopic composition of the plant water reflects that of the root-accessed sources, at least in non-saline or non-xeric environments. However, a growing number of studies challenge this assumption by reporting plant-source offsets in water isotopic composition, for a wide range of ecosystems. We conducted a global meta-analysis to systematically quantify the magnitude of this plant-source offset in water isotopic composition and its potential explanatory factors. We compiled 108 studies reporting dual water isotopic composition (δ<sup>2</sup>H and δ<sup>18</sup>O) of plant and source water. From these studies, we extracted the δ<sup>2</sup>H and δ<sup>18</sup>O of both plant and source waters for 223 plant species from artic to tropical biomes. For each species and sampling campaign, within each study, we calculated the mean line conditioned excess (LC-excess), with the slope and intercept of the local meteoric water line, and the mean soil water line conditioned excess (SWL-excess), from the slope and intercept of the soil water evaporation line. For each study site and sampling campaign, we obtained land surface temperature and volumetric soil water from the ERA5 database. For each study species, we recorded the functional type, leaf habit and for those available wood density. We found, on average, a significantly negative SWL-excess: plant water was systematically more depleted in δ<sup>2</sup>H than soil water. In > 90% of the cases with significantly negative SWL-excess, we also found negative LC-excess values, meaning that access to sources alternative to soil water was unlikely to explain negative SWL-excess values. </p><p>Calculated SWL-excess was affected by temperature and humidity: there were larger mismatches between plant and source water in isotopic composition in colder and wetter sites. Angiosperms, broadleaved and deciduous species exhibited more negative SWL-excess values than gymnosperms, narrow-leaved and evergreen species. Our results suggest that when using the dual isotopic approach, potential biases in the adscription of plant water sources are more likely in broadleaved forests in humid, and cold regions. Potential underlying mechanism for these isotopic mismatches will be discussed.</p><p> </p>

scholarly journals Uncovering the gene machinery of the Amazon River microbiome to degrade rainforest organic matter

2019 ◽  
Author(s):  
Célio Dias Santos ◽  
Hugo Sarmento ◽  
Fernando Pellon de Miranda ◽  
Flávio Henrique-Silva ◽  
Ramiro Logares
Keyword(s):  
Organic Matter ◽  
Lignin Degradation ◽  
Amazon River ◽  
Spatial Distributions ◽  
Gene Repertoire ◽  
Terrestrial Organic Matter ◽  
Incubation Experiments ◽  
Degradation Rates ◽  
Redundant Genes ◽  
Gene Functions

ABSTRACTThe Amazon River receives, from the surrounding rainforest, huge amounts of terrestrial organic matter (TeOM), which is typically resistant to microbial degradation. However, only a small fraction of the TeOM ends up in the ocean, indicating that most of it is degraded in the river. So far, the nature of the genes involved in TeOM degradation and their spatial distributions are barely known. Here, we examined the Amazon River microbiome gene repertoire and found that it contains a substantial gene-novelty, compared to other environments (rivers and rainforest soil). We predicted ~3.7 million non-redundant genes, affiliating mostly to bacteria. The gene-functions involved in TeOM degradation revealed that lignin degradation correlated to tricarboxylates and hemicellulose processing, pointing to higher lignin degradation rates under consumption of labile compounds. We describe the biochemical machinery that could be speeding up the decomposition of recalcitrant compounds in Amazonian waters, previously reported only in incubation experiments.

scholarly journals A CONTRIBUTION TO THE HYDROCHEMISTRY AND WATER TYPOLOGY OF THE AMAZON RIVER AND ITS TRIBUTARIES

2019 ◽  
Vol 20 (72) ◽  
pp. 360-374 ◽  
Author(s):  
Maria do Socorro Rocha da Silva ◽  
Eduardo Antonio Ríos-Villamizar ◽  
Hillândia Brandão da Cunha ◽  
Sebastião Átila Fonseca Miranda ◽  
Sávio José Filgueiras Ferreira ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Physicochemical Properties ◽  
Amazon Basin ◽  
The Other ◽  
Amazon River ◽  
Left Bank ◽  
Guiana Shield ◽  
Ionic Charge ◽  
Physical Chemical ◽  
Geological Diversity

The geological diversity of the Amazon Basin, as well as the pluvial regime, influences the characteristics of the waters. To know the water types of the rivers of the Amazon basin, 288 superficial water samples were collected, 94 of them along the Amazon River and 194 in their tributaries, from March 2009 to September 2012. The physical, chemical, and physicochemical properties were analyzed. Rivers with pH between 6.5 and 7.6 and electrical conductivity (40.00 - 80.00 μS cm-1) are water bodies that are influenced by the Andean region (e.g., the Amazon River and some of its right bank tributaries). On the other hand, the rivers with pH in the range of 3.5 to 5.5 and conductivity <30.00 μS cm-1, which are Amazon River’s left bank tributaries, reflect the characteristics of the Guiana Shield. The rivers with pH (6.0 to 7.0), low ionic charge, and conductivity <40.0 μS cm-1, such as the lower Amazon River’s right bank tributaries (Tapajos and Xingu) which are influenced by the Central Brazilian Shield, and also the middle/upper Amazon River’s right bank tributaries (Tefé, Coari and Jutaí).

scholarly journals Aves, Apodiformes, Trochilidae, Topaza pella (Linnaeus, 1758): a range reinforcement in Amazonian Brazil

Check List ◽  
2010 ◽  
Vol 6 (3) ◽  
pp. 397 ◽  
Author(s):  
Bradley J. W. Davis ◽  
Scott T. Olmstead
Keyword(s):  
Amazon Basin ◽  
Brazilian Amazon ◽  
Amazon River ◽  
Suitable Habitat ◽  
Mato Grosso ◽  
New Localities ◽  
Amazonian Brazil ◽  
New Distribution

We present new distribution records for Topaza pella (Linnaeus, 1758) in the southern reaches of the Amazon Basin in Brazil. The two new localities presented for the species elucidate its range in southern Pará and northern Mato Grosso states, and in consideration of recent records elsewhere south of the Amazon River, suggest that the species is widely distributed across suitable habitat throughout the Brazilian Amazon.

scholarly journals Effectiveness of unmanned aerial vehicles to detect Amazon dolphins

Oryx ◽  
2019 ◽  
Vol 54 (5) ◽  
pp. 696-698 ◽  
Author(s):  
Marcelo Oliveira-da-Costa ◽  
Miriam Marmontel ◽  
Daiane S. X. da-Rosa ◽  
André Coelho ◽  
Serge Wich ◽  
...  
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Amazon Basin ◽  
Accurate Estimate ◽  
Amazon River ◽  
Tropical Rivers ◽  
River Dolphin ◽  
Aerial Vehicles ◽  
Aerial Surveys ◽  
Inia Geoffrensis ◽  
Management And Conservation

AbstractQuantifying the abundance of species is essential for their management and conservation. Much effort has been invested in surveys of freshwater dolphins in the Amazon basin but river dimensions and complex logistics limit replication of such studies across the region. We evaluated the effectiveness of using unmanned aerial vehicles (UAVs) for surveying two Amazon dolphin species, the tucuxi Sotalia fluviatilis and pink river dolphin Inia geoffrensis, in tropical rivers. In 2016 we conducted drone and visual surveys over 80 km of the Juruá River in Brazil. The aerial surveys provided higher accuracy than human observers in counting individuals detected in groups. Compared to estimates derived from visual surveys, the use of UAVs could provide a more feasible, economical and accurate estimate of Amazon river dolphin populations. The method could potentially be replicated in other important areas for the conservation of these species, to generate an improved index of river dolphin populations in the Amazon.

scholarly journals Flow-velocity model for hydrokinetic energy availability assessment in the Amazon

2019 ◽  
Vol 42 ◽  
pp. e45703
Author(s):  
Josias da Silva Cruz ◽  
Claudio José Cavalcante Blanco ◽  
Antônio César Pinho Brasil Junior
Keyword(s):  
Flow Velocity ◽  
Amazon Basin ◽  
Velocity Model ◽  
Amazon River ◽  
Data Series ◽  
Flow Rates ◽  
Hydrokinetic Energy ◽  
Historical Series ◽  
Flood Period ◽  
Availability Assessment

The Brazilian hydrological information network does not provide data series of daily velocities. The river velocities are important for the study of hydrokinetic potential. Therefore, the work proposes a model called flow-velocity that estimates the average daily velocity and the distribution of the velocity profile of the cross section of rivers. The model was applied to the Amazon basin, using the highest and lowest flow rates of the historical series. The highest and lowest average velocities found in the Amazon River were 2.27 m s-1 and 0.735 m s-1, respectively. The main contributors to the Amazon River presented average daily velocities close to 2.0 ms-1 for the flood period, but in the dry season these velocities did not exceed 0.5 m s-1. Thus, it was verified that the Amazon River has hydrokinetic potential throughout the year and its tributaries during the flood period.

Trace Elements in the Mainstem Amazon River

2001 ◽  
Author(s):  
Patrick T. Seyler ◽  
Gerald R. Boaventura
Keyword(s):  
Trace Metals ◽  
Amazon Basin ◽  
Natural Waters ◽  
River System ◽  
Scientific Basis ◽  
Essential Elements ◽  
Amazon River ◽  
Industrialized Countries ◽  
Control Evaluation ◽  
Living Organisms

Measurements of trace metals in rivers are of substantial interest for researchers examining basic scientific questions related to geochemical weathering and transport and to scientists involved in pollution control evaluation. Trace metals in natural waters include essential elements such as cobalt, copper, zinc, manganese, iron, molybdenum, nickel, which may also be toxic at higher concentrations, and nonessential elements, which are toxic, such as cadmium, mercury and lead. Recent findings indicate that iron and, to a lesser extent, zinc and manganese play an important role in regulating the growth and ecology of phytoplankton (Martin et al. 1991), while in contrast, cadmium, arsenic, and mercury have long been recognized as poisonous to living organisms (see Pfeiffer et al. 1993, for a description of mercury problem in the Amazon basin). The release of potentially large quantities of these toxic metals, particularly in the river systems of industrialized countries, but also in tropical rivers, is an acute problem of great environmental concern. An understanding of the weathering and transport processes controlling the fate and flux of trace metals in pristine environments is important in evaluating the capacity of receiving waters to accommodate wastes without detrimental effects. The Amazon River system, which is relatively free of industrial and agricultural interference, represents an ideal case for the investigation of the origin and transport of trace metals. This understanding may also provide a scientific basis for the anticipated development of the Amazon basin. With regard to trace metals, Amazon River is still poorly documented. Martin and Meybeck (1979) and Martin and Gordeev (1986) presented a global tabulation of trace metal concentrations in particulate matter of major rivers including the Amazon, and Palmer and Edmond (1992) measured dissolved Fe, Al, and Sr concentrations in the Amazon mainstream and a number of its tributaries. Boyle et al. (1982) and Gordeev et al. (1990) published some data on Cu, Ni, Cd, and Ag dissolved concentrations at the mouth of the Amazon River and in its oceanic plume. Konhauser et al. (1994) reported the trace and rare earth elemental composition of sediments, soils and waters, mainly in the region of Manaus.

The Late Miocene paleogeography of the Amazon Basin and the evolution of the Amazon River system

2010 ◽  
Vol 99 (3-4) ◽  
pp. 99-124 ◽  
Author(s):  
Edgardo M. Latrubesse ◽  
Mario Cozzuol ◽  
Silane A.F. da Silva-Caminha ◽  
Catherine A. Rigsby ◽  
Maria Lucia Absy ◽  
...  
Keyword(s):  
Late Miocene ◽  
Amazon Basin ◽  
River System ◽  
Amazon River

scholarly journals Diverse Early Life-History Strategies in Migratory Amazonian Catfish: Implications for Conservation and Management

2015 ◽  
Author(s):  
Jens C Hegg ◽  
Tommaso Giarrizzo ◽  
Brian P Kennedy
Keyword(s):  
Life History ◽  
Water Chemistry ◽  
Amazon Basin ◽  
Spatial Scales ◽  
Life History Strategies ◽  
Amazon River ◽  
Sr Isotope ◽  
Chemistry Data ◽  
Fish Migrations ◽  
Conservation And Management

Animal migrations provide important ecological functions and can allow for increased biodiversity through habitat and niche diversification. However, aquatic migrations in general, and those of the world's largest fish in particular, are imperiled worldwide and are often poorly understood. Several species of large Amazonian catfish carry out some of the longest freshwater fish migrations in the world, travelling from the Amazon River estuary to the Andes foothills. These species are important apex predators in the main stem rivers of the Amazon Basin and make up the regions largest fishery. They are also the only species to utilize the entire Amazon Basin to complete their life cycle. Studies indicate both that the fisheries may be declining due to overfishing, and that the proposed and completed dams in their upstream range threaten spawning migrations. Despite this, surprisingly little is known about the details of these species' migrations, or their life history. Otolith microchemistry has been an effective method for quantifying and reconstructing fish migrations worldwide across multiple spatial scales and may provide a powerful tool to understand the movements of Amazonian migratory catfish. Our objective was to describe the migratory behaviors of the three most populous and commercially important migratory catfish species, Dourada (Brachyplatystoma rousseauxii), Piramutaba (Brachyplatystoma vaillantii), and Pira?ba (Brachyplatystoma filamentosum). We collected fish from the mouth of the Amazon River and the Central Amazon and used strontium isotope signatures (87Sr/86Sr) recorded in their otoliths to determine the location of early rearing and subsequent. Fish location was determined through discriminant function classification, using water chemistry data from the literature as a training set. Where water chemistry data was unavailable, we successfully in predicted87Sr/86Sr isotope values using a regression-based approach that related the geology of the upstream watershed to the Sr isotope ratio. Our results provide the first reported otolith microchemical reconstruction of Brachyplatystoma migratory movements in the Amazon Basin. Our results indicate that juveniles exhibit diverse rearing strategies, rearing in both upstream and estuary environments. This contrasts with the prevailing understanding that juveniles rear in the estuary before migrating upstream; however it is supported by some fisheries data that has indicated the presence of alternate spawning and rearing life-histories. The presence of alternate juvenile rearing strategies may have important implications for conservation and management of the fisheries in the region.

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