Trace Metals in the Amazon-Pará River estuary and Brazilian continental shelf: Estimate of the chemical fluxes into the Atlantic Ocean
Abstract
The Amazon River has the largest volume on earth, making up 15–20% of the annual fluvial discharge into oceans. The neighboring Pará River mixes with the Amazon River waters in the Amazon Estuary before forming a plume that extends into the Atlantic. Despite the global importance of these rivers, dissolved trace metal fluxes from this estuary remain unknown. Here we present data for dissolved (<0.2 µm) trace metals (Al, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb and U) in the Amazon Estuary during the high discharge season (April–May 2018). We observed distinct trace metal signatures for the Amazon and Pará Rivers, reflecting different catchment areas. Concentrations of the particle-reactive elements (Mn, Fe and Pb) decreased rapidly at low-salinity (S≤2), resulting in the highest estuarine removal (86–94% in the Amazon; 61–70% for the Pará). Co, Ni and Cu removal was comparatively low in both river transects (6–39%), while Cd was the only element with a consistent net input. Chemical fluxes were estimated using (a) endmember concentrations and estuarine removal and (b) combining trace element concentrations with 228 Ra fluxes. Relative to global total river fluxes, the Amazon and Pará Rivers combined contribute 21% of dissolved Cu and 18% of dissolved Ni during the high discharge season, but account for comparatively low fractions of Mn, Fe, Co and Zn. These data quantify, for the first time, the trace metal output from the world’s largest and 5 th largest river into the Atlantic Ocean, filling a critical gap in knowledge of this globally-important region.
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BibTeX
@article{hollister2026trace,
title = {{Trace Metals in the Amazon-Pará River estuary and Brazilian continental shelf: Estimate of the chemical fluxes into the Atlantic Ocean}},
author = {Adrian Hollister and Morgane Leon and Jan Scholten and Pieter van Beek and Martha Gledhill and Andrea Koschinsky},
journal = {Estuarine, Coastal and Shelf Science},
year = {2026},
month = nov,
doi = {10.1016/j.ecss.2026.110110},
url = {https://hal.science/hal-05854090v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Trace Metals in the Amazon-Pará River estuary and Brazilian continental shelf: Estimate of the chemical fluxes into the Atlantic Ocean
AU - Adrian Hollister
AU - Morgane Leon
AU - Jan Scholten
AU - Pieter van Beek
AU - Martha Gledhill
AU - Andrea Koschinsky
PY - 2026
DA - 2026/11/05
JO - Estuarine, Coastal and Shelf Science
DO - 10.1016/j.ecss.2026.110110
UR - https://hal.science/hal-05854090v1
AB - The Amazon River has the largest volume on earth, making up 15–20% of the annual fluvial discharge into oceans. The neighboring Pará River mixes with the Amazon River waters in the Amazon Estuary before forming a plume that extends into the Atlantic. Despite the global importance of these rivers, dissolved trace metal fluxes from this estuary remain unknown. Here we present data for dissolved (<0.2 µm) trace metals (Al, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb and U) in the Amazon Estuary during the high discharge season (April–May 2018). We observed distinct trace metal signatures for the Amazon and Pará Rivers, reflecting different catchment areas. Concentrations of the particle-reactive elements (Mn, Fe and Pb) decreased rapidly at low-salinity (S≤2), resulting in the highest estuarine removal (86–94% in the Amazon; 61–70% for the Pará). Co, Ni and Cu removal was comparatively low in both river transects (6–39%), while Cd was the only element with a consistent net input. Chemical fluxes were estimated using (a) endmember concentrations and estuarine removal and (b) combining trace element concentrations with 228 Ra fluxes. Relative to global total river fluxes, the Amazon and Pará Rivers combined contribute 21% of dissolved Cu and 18% of dissolved Ni during the high discharge season, but account for comparatively low fractions of Mn, Fe, Co and Zn. These data quantify, for the first time, the trace metal output from the world’s largest and 5 th largest river into the Atlantic Ocean, filling a critical gap in knowledge of this globally-important region.
SN - 0272-7714
SN - 1096-0015
ER -