Dynamics of metals in lacustrine sediments: case study of the Madeira River, Amazon region

Dario Pires De Carvalho,Wanderley Rodrigues Bastos,Ângelo Gilberto Manzatto,Ronaldo De Almeida,Osvaldino Brito De Freitas

doi:10.1590/2318-0331.231820170026

Dario Pires De Carvalho, Wanderley Rodrigues Bastos + Show 3 more

Open Access

https://doi.org/10.1590/2318-0331.231820170026

Copy DOI

Abstract

ABSTRACT The studies on metals in Madeira River’s principal flow show high variability of Co, Cr, Cu, Fe, Ni, Pb and Zn concentrations. However, the transfer of these metals from the main river channel, whose physical and chemical characteristics differ from those of lakes, has not been fully characterized. The objective of this study was to discuss how the transfer of Madeira River’s metals changes the spatial dynamics of these metals in sediments of the Puruzinho Lake (AM). The principal component analysis pointed to differences in the order of the data, creating two distribution zones of metals. The average concentrations of Co, Cu, Cr, Mn and Fe are higher in the area under the influence of the suspended solids coming from the Madeira River. The zoning of metals in lakes is structured by the forces acting across the river’s course at the same time as plains flood and generates ecotones.

Highlights

Metals are present in aquatic ecosystems due to both natural and anthropic processes (KABATA-PENDIAS, 2011)
The present study analyzed the presence of metals in areas characterized by low anthropic activity in the Madeira River Basin, and sheds light on the spatial dynamic of the accumulation of metals in the bottom sediment of Puruzinho Lake, state of Amazonas (AM), Brazil
We studied the compartmentalization of this water body based on the formation of accumulation zones influenced by the interaction between the mainstem flow of Madeira River and the waters of Puruzinho Lake

Summary

INTRODUCTION

Metals are present in aquatic ecosystems due to both natural and anthropic processes (KABATA-PENDIAS, 2011). A metal may go back to the dissolved form due to mineralization processes mediated by the biota or, as observed, the desorption of particles, which in turn depends on physicochemical parameters like the levels of dissolved oxygen, redox potential, pH, and sulfide concentration (MOZETO, 2004; GUILHERME et al, 2005) In this scenario, it is important to highlight the fundamental role of flood pulses in the ecological interactions between terrestrial and aquatic ecosystems in the Amazon (JUNK; WANTZEN, 2003; VIERS et al, 2005). The transfer of metals from whitewater to blackwater rivers has not been investigated in this important aquatic ecosystem In this context, the present study analyzed the presence of metals in areas characterized by low anthropic activity in the Madeira River Basin, and sheds light on the spatial dynamic of the accumulation of metals in the bottom sediment of Puruzinho Lake, state of Amazonas (AM), Brazil.

MATERIALS AND METHODS

RESULTS AND DISCUSSION

CONCLUSIONS