scholarly journals Larvae of migratory Characiformes species in an archipelago in the Lower Amazon River

2021 ◽  
Vol 43 ◽  
pp. e57331
Author(s):  
Lucas Silva de Oliveira ◽  
Ruineris Almada Cajado ◽  
Diego Maia Zacardi
Keyword(s):  
Seasonal Variation ◽  
Amazon Basin ◽  
Hydrological Cycle ◽  
Larval Density ◽  
Main Channel ◽  
Amazon River ◽  
Great Capacity ◽  
Fish Stocks ◽  
Lack Of Information ◽  
Spatial And Seasonal Variation

In the Amazon basin, most of the migratory Characiformes species represent an important fishing resource for local people. However, the lack of information about the main areas and periods of reproduction and the importance of certain environments for the maintenance of species may jeopardize the renewal of fish stocks. Thus, the aim was to examine the spatial and seasonal variation in the density of larvae of migratory Characiformes species in an archipelago in the Lower Amazon River and to assess the importance of this environment for the biological recruitment of the studied species. The capture of larvae was carried out in places close to restinga swamps, steep ruts, and inlet areas with a plankton net (300 µm) in monthly sampling from January to December 2013. An analysis of variance was used to verify differences in larval density between seasons and sampling months. A total of 30,997 larvae were captured and showed no significant differences in their distributions between habitats. However, a variation between the phases of the hydrological cycle was evident, in which the highest larval concentrations were observed during the flooding (17.72 larvae.10m-3) and the drought (1.33 larvae.10m-3). The study area has a great capacity to assist in the maintenance and renewal of regional fish stocks, as it is an important retention and nursery site for larvae of Characiformes that drift along the main channel of the Amazon River.

scholarly journals Evapotranspiration in the Amazon: spatial patterns, seasonality and recent trends in observations, reanalysis and CMIP models

2020 ◽  
Author(s):  
Jessica C. A. Baker ◽  
Luis Garcia-Carreras ◽  
Manuel Gloor ◽  
John H. Marsham ◽  
Wolfgang Buermann ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Amazon Basin ◽  
Climate Models ◽  
Hydrological Cycle ◽  
Coupled Model ◽  
Spatial And Temporal Patterns ◽  
Wet Season ◽  
Comprehensive Overview ◽  
Spatial And Seasonal Variation ◽  
Balance Analysis

Abstract. Water recycled through transpiring forests influences the spatial distribution of precipitation in the Amazon and has been shown to play a role in the initiation of the wet season. However, due to the challenges and costs associated with measuring evapotranspiration (ET) directly, plus the high uncertainty and discrepancies across remote-sensing retrievals of ET, spatial and temporal patterns in this key component of the Amazon hydrological cycle remain poorly understood. In this study, we estimated ET over the Amazon and ten sub-basins using a catchment-balance approach, whereby ET is calculated directly as the balance between precipitation, runoff and change in groundwater storage. We compared our results with ET from remote-sensing datasets, reanalysis, models from the fifth and sixth Coupled Model Intercomparison Projects (CMIP5 and CMIP6), and in-situ flux-tower measurements, to provide a comprehensive overview of current understanding. Catchment-balance analysis revealed a gradient in ET from east to west/southwest across the Amazon basin, a strong seasonal cycle in basin-mean ET controlled by net incoming radiation, and no trend in ET over the past two decades. Satellite datasets, reanalysis and climate models all tended to overestimate the magnitude of ET relative to catchment-balance estimates, underestimate seasonal and interannual variability, and show conflicting positive and negative trends. Only two out of six satellite and model datasets analysed reproduced spatial and seasonal variation in Amazon ET, and captured the same controls on ET as indicated by catchment-balance analysis. CMIP5 and CMIP6 ET was inconsistent with catchment-balance estimates over all scales analysed. Overall, the discrepancies between data products and models revealed by our analysis demonstrate a need for more ground-based ET measurements in the Amazon, and to substantially improve model representation of this fundamental component of the Amazon hydrological cycle.

scholarly journals Evapotranspiration in the Amazon: spatial patterns, seasonality, and recent trends in observations, reanalysis, and climate models

2021 ◽  
Vol 25 (4) ◽  
pp. 2279-2300
Author(s):  
Jessica C. A. Baker ◽  
Luis Garcia-Carreras ◽  
Manuel Gloor ◽  
John H. Marsham ◽  
Wolfgang Buermann ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Amazon Basin ◽  
Climate Models ◽  
Hydrological Cycle ◽  
Coupled Model ◽  
Spatial And Temporal Patterns ◽  
Wet Season ◽  
Comprehensive Overview ◽  
Spatial And Seasonal Variation ◽  
Balance Analysis

Abstract. Water recycled through transpiring forests influences the spatial distribution of precipitation in the Amazon and has been shown to play a role in the initiation of the wet season. However, due to the challenges and costs associated with measuring evapotranspiration (ET) directly and high uncertainty in remote-sensing ET retrievals, the spatial and temporal patterns in Amazon ET remain poorly understood. In this study, we estimated ET over the Amazon and 10 sub-basins using a catchment-balance approach, whereby ET is calculated directly as the balance between precipitation, runoff, and change in groundwater storage. We compared our results with ET from remote-sensing datasets, reanalysis, models from Phase 5 and Phase 6 of the Coupled Model Intercomparison Projects (CMIP5 and CMIP6 respectively), and in situ flux tower measurements to provide a comprehensive overview of current understanding. Catchment-balance analysis revealed a gradient in ET from east to west/southwest across the Amazon Basin, a strong seasonal cycle in basin-mean ET primarily controlled by net incoming radiation, and no trend in ET over the past 2 decades. This approach has a degree of uncertainty, due to errors in each of the terms of the water budget; therefore, we conducted an error analysis to identify the range of likely values. Satellite datasets, reanalysis, and climate models all tended to overestimate the magnitude of ET relative to catchment-balance estimates, underestimate seasonal and interannual variability, and show conflicting positive and negative trends. Only two out of six satellite and model datasets analysed reproduced spatial and seasonal variation in Amazon ET, and captured the same controls on ET as indicated by catchment-balance analysis. CMIP5 and CMIP6 ET was inconsistent with catchment-balance estimates over all scales analysed. Overall, the discrepancies between data products and models revealed by our analysis demonstrate a need for more ground-based ET measurements in the Amazon as well as a need to substantially improve model representation of this fundamental component of the Amazon hydrological cycle.

Spatial and seasonal variation in littoral fish assemblages of four estuarine lagoons on the Mexican Pacific coast

2021 ◽  
pp. 102000
Author(s):  
Yureidy Cabrera-Páez ◽  
Consuelo M. Aguilar-Betancourt ◽  
Gaspar González-Sansón ◽  
Angel Hinojosa-Larios
Keyword(s):  
Seasonal Variation ◽  
Pacific Coast ◽  
Fish Assemblages ◽  
Mexican Pacific ◽  
Littoral Fish ◽  
Spatial And Seasonal Variation

scholarly journals IMPACTS OF LAND COVER AND GREENHOUSE GAS (GHG) CONCENTRATION CHANGES ON THE HYDROLOGICAL CYCLE IN AMAZON BASIN: A REGIONAL CLIMATE MODEL STUDY

2015 ◽  
Vol 15 ◽  
Author(s):  
Vinícius Machado Rocha ◽  
Francis Wagner Silva Correia ◽  
Prakki Satyamurty ◽  
Saulo Ribeiro De Freitas ◽  
Demerval Soares Moreira ◽  
...  
Keyword(s):  
Land Cover ◽  
Regional Climate Model ◽  
Greenhouse Gas ◽  
Amazon Basin ◽  
Climate Model ◽  
Hydrological Cycle ◽  
Regional Climate ◽  
Model Study ◽  
Concentration Changes

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.

Sign in / Sign up

Export Citation Format

Share Document