Spatial and seasonal contrasts of sedimentary organic matter in floodplain lakes of the central Amazon basin

Abstract. In this study, we investigated the seasonal and spatial pattern of sedimentary organic matter (SOM) in five floodplain lakes of the central Amazon basin (Cabaliana, Janauaca, Canaçari, Miratuba, and Curuai) which have different morphologies, hydrodynamics and vegetation coverages. Surface sediments were collected in four hydrological seasons: low water (LW), rising water (RW), high water (HW) and falling water (FW) in 2009 and 2010. We investigated commonly used bulk geochemical tracers such as the C : N ratio and the stable isotopic composition of organic carbon (δ13Corg). These results were compared with lignin-phenol parameters as an indicator of vascular plant detritus and branched glycerol dialkyl glycerol tetraethers (brGDGTs) to trace the input of soil organic matter (OM) from land to the aquatic settings. We also applied the isoprenoid GDGT (iGDGT) crenarchaeol as an indicator of riverine suspended particulate organic matter (SPOM). Our data showed that during the RW and FW seasons, the surface sediments were enriched in lignin and brGDGTs in comparison to other seasons. Our study also indicated that floodplain lake sediments primarily consisted of allochthonous, C3 plant-derived OM. However, a downstream increase in C4 macrophyte derived OM contribution was observed along the gradient of increasing open waters, i.e. from upstream to downstream. Accordingly, we attribute temporal and spatial difference in SOM composition to the hydrological dynamics between the floodplain lakes and the surrounding flooded forests.

Download Full-text

Spatial and seasonal contrasts of sedimentary organic matter in floodplain lakes of the central Amazon basin

Biogeosciences ◽

10.5194/bg-13-467-2016 ◽

2016 ◽

Vol 13 (2) ◽

pp. 467-482 ◽

Cited By ~ 5

Author(s):

R. L. Sobrinho ◽

M. C. Bernardes ◽

G. Abril ◽

J.-H. Kim ◽

C. I Zell ◽

...

Keyword(s):

Organic Matter ◽

Amazon Basin ◽

Surface Sediments ◽

Vascular Plant ◽

High Water ◽

Floodplain Lakes ◽

Sedimentary Organic Matter ◽

C3 Plant ◽

Geochemical Tracers ◽

Central Amazon

Abstract. In this study, we investigated the seasonal and spatial pattern of sedimentary organic matter (SOM) in five floodplain lakes of the central Amazon basin (Cabaliana, Janauaca, Canaçari, Mirituba and Curuai) which have different morphologies, hydrodynamics and vegetation coverages. Surface sediments were collected in four hydrological seasons: low water (LW), rising water (RW), high water (HW) and falling water (FW) in 2009 and 2010. We investigated commonly used bulk geochemical tracers such as the C : N ratio and the stable isotopic composition of organic carbon (δ13Corg). These results were compared with lignin phenol parameters as an indicator of vascular plant detritus and branched glycerol dialkyl glycerol tetraethers (brGDGTs) to trace the input of soil organic matter (OM) from land to the aquatic settings. We also applied the crenarchaeol as an indicator of aquatic (rivers and lakes) OM. Our data showed that during the RW and FW seasons, the surface sediments were enriched in lignin and brGDGTs in comparison to other seasons. Our study also indicated that floodplain lake sediments primarily consisted of allochthonous, C3 plant-derived OM. However, a downstream increase in C4 macrophyte-derived OM contribution was observed along the gradient of increasing open waters – i.e., from upstream to downstream. Accordingly, we attribute the temporal and spatial difference in SOM composition to the hydrological dynamics between the floodplain lakes and the surrounding flooded forests.

Download Full-text

Sedimentary organic matter diagenesis and its relation to the carbon budget of tropical Amazon floodplain lakes

SIL Proceedings 1922-2010 ◽

10.1080/03680770.1983.11897489 ◽

1984 ◽

Vol 22 (2) ◽

pp. 1299-1304 ◽

Cited By ~ 3

Author(s):

Allan H. Devol ◽

Thomas M. Zaret ◽

Bruce R. Forsberg

Keyword(s):

Organic Matter ◽

Carbon Budget ◽

Floodplain Lakes ◽

Sedimentary Organic Matter ◽

Amazon Floodplain

Download Full-text

Dissolved organic matter and terrestrial-lotic linkages in the Central Amazon Basin of Brazil

Global Biogeochemical Cycles ◽

10.1029/97gb01056 ◽

1997 ◽

Vol 11 (3) ◽

pp. 295-311 ◽

Cited By ~ 72

Author(s):

Michael E. McClain ◽

Jeffrey E. Richey ◽

Jay A. Brandes ◽

Tania P. Pimentel

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Amazon Basin ◽

Central Amazon

Download Full-text

Length-weight relationships and length at first maturity for nine fish species of floodplain lakes in Central Amazon (Amazon Basin, Brazil)

Journal of Applied Ichthyology ◽

10.1111/jai.12919 ◽

2015 ◽

Vol 31 (6) ◽

pp. 1182-1184 ◽

Cited By ~ 4

Author(s):

L. Dieb-Magalhães ◽

A. C. Florentino ◽

M. G. Mota Soares

Keyword(s):

Fish Species ◽

Amazon Basin ◽

Floodplain Lakes ◽

Central Amazon ◽

First Maturity

Download Full-text

Intra- and inter-annual changes in the condition factors of three Curimatidae detritivores from Amazonian floodplain lakes

Biota Neotropica ◽

10.1590/1676-0611-bn-2014-0001 ◽

2015 ◽

Vol 15 (4) ◽

Cited By ~ 1

Author(s):

Gisele Batista Correia ◽

Flávia Kelly Siqueira-Souza ◽

Carlos Edwar de Carvalho Freitas

Keyword(s):

Amazon Basin ◽

Hydrological Cycle ◽

Global Climate ◽

High Water ◽

Flood Pulse ◽

Floodplain Lakes ◽

Key Factor ◽

Length Data ◽

Dry Seasons ◽

Annual Changes

The flood pulse is a key factor that drives the biota of large rivers with adjacent floodplains, but the direction and intensity of its effects are not uniform for all trophic guilds of fish. In this study, we tested the existence of intra- and inter-annual changes in the relative condition factors (kn) of three Curimatidae: Potamorhina altamazonica, Potamorhina latior, and Psectrogaster rutiloides. We used weight and length data from fish that were caught in eight floodplain lakes of the Rio Solimões. These data were from experimental fisheries during each season of the hydrological cycle: flooding, flood, drying, and dry from 2004, 2005, and 2006. In general, there are similar patterns of intra-annual changes for these three species, with the highest estimates of kn during high water conditions. The lowest values were observed during the drying and dry seasons of 2005, when an extreme drought occurred in the Amazon basin. Higher values were observed during the same seasons in the year post-drought. We hypothesized that these patterns would be explained by the biological characteristics of these species and the effects of intra-annual hydrological changes, mainly the flood pulse effect, and by inter-annual climatic events, which are determined by global climate phenomena.

Download Full-text

Patterns of Pelagic Fish Diversity in Floodplain Lakes of Whitewater and Blackwater Drainage Systems Within the Central Amazon River Basin of Brazil

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.602895 ◽

2021 ◽

Vol 9 ◽

Author(s):

Flávia K. Siqueira-Souza ◽

Lawrence E. Hurd ◽

Kedma C. Yamamoto ◽

Maria Gercilia M. Soares ◽

Gregory J. Cooper ◽

...

Keyword(s):

Species Richness ◽

Species Composition ◽

River Basin ◽

Amazon Basin ◽

Pelagic Fish ◽

Floodplain Lakes ◽

Fish Diversity ◽

River Systems ◽

Amazon River Basin ◽

Central Amazon

The Amazon River Basin, one of the world’s most threatened ecosystems, has an enormous diversity of fish species, a result of temporally and spatially complex habitat containing biogeochemically different river systems. The annual hydrologic cycle results in floodplain lakes during low water and inundates forests during high water, exposing fish to different resources and environmental conditions. The two principal river systems in the central Brazilian Amazon are blackwater, with nutrient-poor acidic water, and nutrient-rich whitewater. Although species-rich, the Amazon Basin is data-poor in terms of comparative studies on a regional scale. We analyzed data sets from independent sampling studies of pelagic fish in 16 floodplain lakes, nine whitewater (Rio Solimões) and seven blackwater (Rio Negro), in the central Amazon Basin of Brazil. Our findings suggest striking similarities in pelagic fish diversity patterns. Species richness was virtually equal (165 in whitewater and 168 in blackwater). Both species richness, and number of migratory species, per lake increased toward the confluence of the rivers in both systems in our study. The proportion of unique species was also similar in whitewater lakes and blackwater (41 and 43%, respectively), boosting total regional richness to 237 species. However, species composition in whitewater lakes was more homogenous (lower β diversity), and species composition was associated with conductivity and pH in whitewater, but with dissolved oxygen and transparency in blackwater. Therefore, regional fish diversity cannot be represented by sampling one lake or even one drainage system, but must include multiple lakes from both systems. These two systems may differ in sensitivity to anthropogenic stressors such as damming and deforestation.

Download Full-text

Biogeochemistry of Amazon Floodplain Lakes and Associated Wetlands

The Biogeochemistry of the Amazon Basin ◽

10.1093/oso/9780195114317.003.0017 ◽

2001 ◽

Author(s):

John M. Melack ◽

Bruce R. Forsberg

Keyword(s):

Amazon Basin ◽

Nutrient Retention ◽

Open Water ◽

Floodplain Lakes ◽

New Paradigm ◽

Central Amazon ◽

Amazon Floodplain ◽

Flooded Forests ◽

The Many ◽

Floating Macrophytes

Floodplains and associated lakes are important components of the biogeochemistry, ecology, and hydrology of the Amazon basin. Amazon floodplains contain thousands of lakes and associated wetlands linked to each other and to the many rivers of the immense basin. These floodplain lakes modify the passage of flood waves (Richey et al. 1989a), increase nutrient retention and recycling (Melack and Fisher 1990), and influence the chemistry of the rivers (Devol et al. 1995). The mosaic of flooded forests, open water, and floating macrophytes in the central Amazon floodplain makes a significant contribution of methane to the troposphere (Bartlett et al. 1988, Devol et al. 1990). The fishery potential of the large river systems is closely tied to the area of floodplain and the magnitude and duration of inundation (Welcomme 1979, Bayley and Petrere 1989). The majority of fishes harvested in the Amazon basin obtain nutrition in flooded forests (Goulding 1980) or from organic matter derived from floodplain algae (Araujo-Lima et al. 1986, Forsberg et al. 1993). Much progress has been made during the last fifty years toward understanding the lakes of the Amazon floodplain. Still, the vast size of the Amazon basin poses challenges to limnologists working in the region. Recent research has been enhanced by the maintenance of functional floating laboratories in several areas, use of modern ships capable of regional surveys and equipped for hydrographic studies, and applications of remote sensing. Our objective in this chapter is to examine the role of lakes in the hydrology of the floodplain and in the biogeochemistry of carbon, nitrogen, and phosphorous within the central Amazon basin. Particular emphasis is placed on how inundation patterns interplay with carbon balance and nutrient limitation. By combining numerous measurements of primary productivity with recent results from studies using isotopes of carbon, we will examine the contribution of the major plant groups to aquatic foodwebs, and offer a new paradigm for the processing of organic carbon on the Amazon floodplain. The interplay between the Amazon River and local catchments as sources of nutrients to the floodplain indicates the potential sensitivity of the lakes to basin-wide and local disturbances.

Download Full-text

Composition and sources of sedimentary organic matter in the deep eastern Mediterranean Sea

Biogeosciences ◽

10.5194/bg-12-7379-2015 ◽

2015 ◽

Vol 12 (24) ◽

pp. 7379-7402 ◽

Cited By ~ 10

Author(s):

R. Pedrosa-Pàmies ◽

C. Parinos ◽

A. Sanchez-Vidal ◽

A. Gogou ◽

A. Calafat ◽

...

Keyword(s):

Organic Matter ◽

Mediterranean Sea ◽

Surface Sediments ◽

Eastern Mediterranean ◽

Sedimentary Organic Matter ◽

Eastern Mediterranean Sea ◽

Deep Sea Sediment ◽

Fine Grained ◽

Circulation Patterns ◽

The Impact

Abstract. Surface sediments collected from deep slopes and basins (1018–4087 m depth) of the oligotrophic eastern Mediterranean Sea have been analysed for bulk elemental and isotopic composition of organic carbon, total nitrogen and selected lipid biomarkers, jointly with grain size distribution and other geochemical proxies. The distribution and sources of sedimentary organic matter (OM) have been subsequently assessed and general environmental variables, such as water column depth and physical circulation patterns, have been examined as causative factors of deep-sea sediment characteristics. Lithogenic and biogenic carbonates are the dominant sedimentary fractions, accounting for up to 85.4 and 66.5 % of the total weight respectively. The low OC and TN contents in the surface sediments of the study area, which ranged from 0.15 to 1.15 % and 0.06 to 0.11 % respectively, reflect the oligotrophic character of the eastern Mediterranean Sea. Both bulk and molecular organic tracers reflect a mixed contribution from autochthonous and allochthonous sources for the sedimentary OM, as indicated by relatively degraded marine OM, terrestrial plant waxes and anthropogenic OM (e.g. degraded petroleum by-products) respectively. Wide regional variations have been observed amongst the studied proxies, which reflect the multiple factors controlling sedimentation in the deep eastern Mediterranean Sea. Our findings highlight the role of deep eastern Mediterranean basins as depocentres of organic-rich fine-grained sediments (mean 5.4 ± 2.4 μm), with OM accumulation and burial being attributed to aggregation mechanisms and hydrodynamic sorting. A multi-proxy approach is applied aiming to investigate the biogeochemical composition of sediment samples, which sheds new light on the sources and transport mechanisms along with the impact of preservation vs. diagenetic processes on the composition of sedimentary OM in the deep basins of the oligotrophic eastern Mediterranean Sea.

Download Full-text