Riverine connectivity modulates elemental fluxes through a 200- year period of intensive anthropic change in the Magdalena River floodplains, Colombia

Jorge Salgado; Camila Jaramillo-Monroy; Andrés Link; Laura Lopera-Congote; Maria I. Velez; Catalina Gonzalez-Arango; Handong Yang; Virginia N. Panizzo; Suzanne McGowan

doi:10.1016/j.watres.2024.122633

Riverine connectivity modulates elemental fluxes through a 200- year period of intensive anthropic change in the Magdalena River floodplains, Colombia

Jorge Salgado^* (Corresponding author), Camila Jaramillo-Monroy, Andrés Link, Laura Lopera-Congote, Maria I. Velez, Catalina Gonzalez-Arango, Handong Yang, Virginia N. Panizzo, Suzanne McGowan

^*Corresponding author for this work

NIOO - Aquatic Ecology (AqE)

Research output: Contribution to journal/periodical › Article › Scientific › peer-review

Abstract

Tropical floodplain lakes are increasingly impacted by human activities, yet their pathways of spatial and temporal degradation, particularly under varying hydrological connectivity regimes and climate change, remain poorly understood. This study examines surface-sediment samples and ²¹⁰Pb-dated sediment cores from six floodplain lakes, representing a gradient in hydrological connectivity in the lower Magdalena River Basin, Colombia. We analysed temporal and spatial variations in several sediment biogeochemical indicators: the concentration and flux of nutrients, heavy metals, and organic matter (OM), and redox conditions, flooding and erosion. Multiple factor analysis (MFA) of surface-sediments identified redox conditions, OM, flooding, heavy metals and lake connectivity as the main contributors to spatial variability within- and between-lakes sediments, accounting for 48 % of the total variation. Additionally, no clear distinction was found between littoral and open-water sediment characteristics. Isolated lakes sediments exhibited reductive conditions rich in OM and nutrients, whereas connected lakes sediments showed greater heavy metal enrichment and higher concentrations of coarse river-fed material. Generalised additive models identified significant changes in the biogeochemical indicators since the late 1800s, that accelerated post-1980s. Shifts in OM, erosion, flooding, redox conditions, land-cover change, heavy metals and climate were identified by MFA as the main drivers of change, explaining 60 %-71 % of the variation in the connected lakes and 53 %-72 % in the isolated lakes. Post-1980s, connected lakes transitioned from conditions of higher accumulation of OM and little erosion to higher accumulation of heavy metals and river-fed material. Conversely, isolated lakes, shifted from detrital-heavy metal-rich sediments to OM-, and nutrient-rich, reductive sediments. Sedimentation rates also surged post-1980s, particularly in highly connected lakes, from 0.14 ± 0.07 g cm² yr⁻¹ to 0.5 ± 0.5 g cm² yr⁻¹, with elevated fluxes of metals, OM and nutrients. These changes in sediment biogeochemistry align with deforestation, river regulation and prolonged dry periods, highlighting the complexities behind establishing reliable reference conditions for pollution assessments in large, human-impacted tropical river systems.

Original language	English
Article number	122633
Journal	Water Research
Volume	268
Issue number	A
Early online date	28 Oct 2024
DOIs	https://doi.org/10.1016/j.watres.2024.122633
Publication status	E-pub ahead of print - 28 Oct 2024

Keywords

Biogeochemistry
Climate variability
Eutrophication
Floodplain lakes
Magdalena River
Palaeolimnology
River damming
Sediment pollution
Tropical Rivers

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10.1016/j.watres.2024.122633Licence: CC BY-NC-ND

Cite this

Salgado, J., Jaramillo-Monroy, C., Link, A., Lopera-Congote, L., Velez, M. I., Gonzalez-Arango, C., Yang, H., Panizzo, V. N., & McGowan, S. (2025). Riverine connectivity modulates elemental fluxes through a 200- year period of intensive anthropic change in the Magdalena River floodplains, Colombia. Water Research, 268(A), Article 122633. Advance online publication. https://doi.org/10.1016/j.watres.2024.122633

@article{1551152eff7048e78aa57d0787cb9735,

title = "Riverine connectivity modulates elemental fluxes through a 200- year period of intensive anthropic change in the Magdalena River floodplains, Colombia",

abstract = "Tropical floodplain lakes are increasingly impacted by human activities, yet their pathways of spatial and temporal degradation, particularly under varying hydrological connectivity regimes and climate change, remain poorly understood. This study examines surface-sediment samples and 210Pb-dated sediment cores from six floodplain lakes, representing a gradient in hydrological connectivity in the lower Magdalena River Basin, Colombia. We analysed temporal and spatial variations in several sediment biogeochemical indicators: the concentration and flux of nutrients, heavy metals, and organic matter (OM), and redox conditions, flooding and erosion. Multiple factor analysis (MFA) of surface-sediments identified redox conditions, OM, flooding, heavy metals and lake connectivity as the main contributors to spatial variability within- and between-lakes sediments, accounting for 48 % of the total variation. Additionally, no clear distinction was found between littoral and open-water sediment characteristics. Isolated lakes sediments exhibited reductive conditions rich in OM and nutrients, whereas connected lakes sediments showed greater heavy metal enrichment and higher concentrations of coarse river-fed material. Generalised additive models identified significant changes in the biogeochemical indicators since the late 1800s, that accelerated post-1980s. Shifts in OM, erosion, flooding, redox conditions, land-cover change, heavy metals and climate were identified by MFA as the main drivers of change, explaining 60 %-71 % of the variation in the connected lakes and 53 %-72 % in the isolated lakes. Post-1980s, connected lakes transitioned from conditions of higher accumulation of OM and little erosion to higher accumulation of heavy metals and river-fed material. Conversely, isolated lakes, shifted from detrital-heavy metal-rich sediments to OM-, and nutrient-rich, reductive sediments. Sedimentation rates also surged post-1980s, particularly in highly connected lakes, from 0.14 ± 0.07 g cm² yr⁻¹ to 0.5 ± 0.5 g cm² yr⁻¹, with elevated fluxes of metals, OM and nutrients. These changes in sediment biogeochemistry align with deforestation, river regulation and prolonged dry periods, highlighting the complexities behind establishing reliable reference conditions for pollution assessments in large, human-impacted tropical river systems.",

keywords = "Biogeochemistry, Climate variability, Eutrophication, Floodplain lakes, Magdalena River, Palaeolimnology, River damming, Sediment pollution, Tropical Rivers",

author = "Jorge Salgado and Camila Jaramillo-Monroy and Andr{\'e}s Link and Laura Lopera-Congote and Velez, {Maria I.} and Catalina Gonzalez-Arango and Handong Yang and Panizzo, {Virginia N.} and Suzanne McGowan",

note = "Data archiving: on request",

year = "2024",

month = oct,

day = "28",

doi = "10.1016/j.watres.2024.122633",

language = "English",

volume = "268",

journal = "Water Research",

issn = "0043-1354",

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Salgado, J, Jaramillo-Monroy, C, Link, A, Lopera-Congote, L, Velez, MI, Gonzalez-Arango, C, Yang, H, Panizzo, VN & McGowan, S 2025, 'Riverine connectivity modulates elemental fluxes through a 200- year period of intensive anthropic change in the Magdalena River floodplains, Colombia', Water Research, vol. 268, no. A, 122633. https://doi.org/10.1016/j.watres.2024.122633

Riverine connectivity modulates elemental fluxes through a 200- year period of intensive anthropic change in the Magdalena River floodplains, Colombia. / Salgado, Jorge (Corresponding author); Jaramillo-Monroy, Camila; Link, Andrés et al.
In: Water Research, Vol. 268, No. A, 122633, 01.01.2025.

Research output: Contribution to journal/periodical › Article › Scientific › peer-review

TY - JOUR

T1 - Riverine connectivity modulates elemental fluxes through a 200- year period of intensive anthropic change in the Magdalena River floodplains, Colombia

AU - Salgado, Jorge

AU - Jaramillo-Monroy, Camila

AU - Link, Andrés

AU - Lopera-Congote, Laura

AU - Velez, Maria I.

AU - Gonzalez-Arango, Catalina

AU - Yang, Handong

AU - Panizzo, Virginia N.

AU - McGowan, Suzanne

N1 - Data archiving: on request

PY - 2024/10/28

Y1 - 2024/10/28

N2 - Tropical floodplain lakes are increasingly impacted by human activities, yet their pathways of spatial and temporal degradation, particularly under varying hydrological connectivity regimes and climate change, remain poorly understood. This study examines surface-sediment samples and 210Pb-dated sediment cores from six floodplain lakes, representing a gradient in hydrological connectivity in the lower Magdalena River Basin, Colombia. We analysed temporal and spatial variations in several sediment biogeochemical indicators: the concentration and flux of nutrients, heavy metals, and organic matter (OM), and redox conditions, flooding and erosion. Multiple factor analysis (MFA) of surface-sediments identified redox conditions, OM, flooding, heavy metals and lake connectivity as the main contributors to spatial variability within- and between-lakes sediments, accounting for 48 % of the total variation. Additionally, no clear distinction was found between littoral and open-water sediment characteristics. Isolated lakes sediments exhibited reductive conditions rich in OM and nutrients, whereas connected lakes sediments showed greater heavy metal enrichment and higher concentrations of coarse river-fed material. Generalised additive models identified significant changes in the biogeochemical indicators since the late 1800s, that accelerated post-1980s. Shifts in OM, erosion, flooding, redox conditions, land-cover change, heavy metals and climate were identified by MFA as the main drivers of change, explaining 60 %-71 % of the variation in the connected lakes and 53 %-72 % in the isolated lakes. Post-1980s, connected lakes transitioned from conditions of higher accumulation of OM and little erosion to higher accumulation of heavy metals and river-fed material. Conversely, isolated lakes, shifted from detrital-heavy metal-rich sediments to OM-, and nutrient-rich, reductive sediments. Sedimentation rates also surged post-1980s, particularly in highly connected lakes, from 0.14 ± 0.07 g cm² yr⁻¹ to 0.5 ± 0.5 g cm² yr⁻¹, with elevated fluxes of metals, OM and nutrients. These changes in sediment biogeochemistry align with deforestation, river regulation and prolonged dry periods, highlighting the complexities behind establishing reliable reference conditions for pollution assessments in large, human-impacted tropical river systems.

AB - Tropical floodplain lakes are increasingly impacted by human activities, yet their pathways of spatial and temporal degradation, particularly under varying hydrological connectivity regimes and climate change, remain poorly understood. This study examines surface-sediment samples and 210Pb-dated sediment cores from six floodplain lakes, representing a gradient in hydrological connectivity in the lower Magdalena River Basin, Colombia. We analysed temporal and spatial variations in several sediment biogeochemical indicators: the concentration and flux of nutrients, heavy metals, and organic matter (OM), and redox conditions, flooding and erosion. Multiple factor analysis (MFA) of surface-sediments identified redox conditions, OM, flooding, heavy metals and lake connectivity as the main contributors to spatial variability within- and between-lakes sediments, accounting for 48 % of the total variation. Additionally, no clear distinction was found between littoral and open-water sediment characteristics. Isolated lakes sediments exhibited reductive conditions rich in OM and nutrients, whereas connected lakes sediments showed greater heavy metal enrichment and higher concentrations of coarse river-fed material. Generalised additive models identified significant changes in the biogeochemical indicators since the late 1800s, that accelerated post-1980s. Shifts in OM, erosion, flooding, redox conditions, land-cover change, heavy metals and climate were identified by MFA as the main drivers of change, explaining 60 %-71 % of the variation in the connected lakes and 53 %-72 % in the isolated lakes. Post-1980s, connected lakes transitioned from conditions of higher accumulation of OM and little erosion to higher accumulation of heavy metals and river-fed material. Conversely, isolated lakes, shifted from detrital-heavy metal-rich sediments to OM-, and nutrient-rich, reductive sediments. Sedimentation rates also surged post-1980s, particularly in highly connected lakes, from 0.14 ± 0.07 g cm² yr⁻¹ to 0.5 ± 0.5 g cm² yr⁻¹, with elevated fluxes of metals, OM and nutrients. These changes in sediment biogeochemistry align with deforestation, river regulation and prolonged dry periods, highlighting the complexities behind establishing reliable reference conditions for pollution assessments in large, human-impacted tropical river systems.

KW - Biogeochemistry

KW - Climate variability

KW - Eutrophication

KW - Floodplain lakes

KW - Magdalena River

KW - Palaeolimnology

KW - River damming

KW - Sediment pollution

KW - Tropical Rivers

U2 - 10.1016/j.watres.2024.122633

DO - 10.1016/j.watres.2024.122633

M3 - Article

AN - SCOPUS:85207637573

SN - 0043-1354

VL - 268

JO - Water Research

JF - Water Research

IS - A

M1 - 122633

ER -