Organic matter and seasonal flooding control mercury and methane distribution in sediments of a floodplain lake in the Madeira River basin (western Amazon)
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Le résumé fourni par la source
We investigated the spatial distribution and environmental controls of total Hg (THg), methane (CH 4 ), and nutrient accumulation in the sediments of an Amazonian lake during low-water and high-water periods. THg concentrations were similar between hydrological periods (0.103 ± 0.035 mg kg −1 in low water; 0.104 ± 0.039 mg kg −1 in high water) and were consistently associated with organic matter (TOC) and nitrogen (N). In contrast, CH 4 exhibited strong seasonal variability, with significantly higher concentrations during high water (7.94 ± 4.35 mg kg −1 ) compared to low water (4.43 ± 3.05 mg kg −1 ). Phosphorus (P) and water depth also increased markedly during high water, reflecting enhanced hydrological connectivity. Geostatistical analyses revealed that THg, TOC, and N shared similar spatial patterns, with higher concentrations in central and distal portions of the lake, whereas CH 4 was more spatially variable. Generalized least squares models indicated that THg was primarily controlled by TOC and pH during low water and by N during high water, whereas CH 4 was influenced by TOC in low water and by N and water depth in high water. Spatial congruence between THg and TOC (54.1%) and between THg and N (51.7%) was moderate, increasing substantially under relaxed criteria (>93%). Methane showed weaker spatial correspondence with its predictors. These results demonstrate that hydrological seasonality decouples Hg and CH 4 dynamics, with Hg strongly linked to organic matter and CH 4 responding to shifts in nutrient availability and water column conditions.
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Le contrôle bibliographique ouvert
DOI retrouvé dans Crossref DOI retrouvé ; titre concordant.
- Titre Crossref
- Organic matter and seasonal flooding control mercury and methane distribution in sediments of a floodplain lake in the Madeira River basin (western Amazon)
- Date Crossref
- 01/09/2026
- Éditeur
- Elsevier BV
- Type
- journal-article
Ce recoupement confirme des métadonnées liées au DOI. Il ne confirme ni la méthode ni les conclusions de l’étude, et il ne compte pas comme une seconde source scientifique indépendante.
Où se fait cette recherche
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Universidade de Brasília Faculdade UnB Planaltina pays non établi dans la noticeUniversité ou école supérieure
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Universidade Federal do Rio de Janeiro Instituto de Biofísica Carlos Chagas Filho (IBCCF) pays non établi dans la noticeUniversité ou école supérieure
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Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro pays non établi dans la noticeStructure de recherche
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Universidade Federal de Rondônia Laboratório de Biogeoquímica Ambiental pays non établi dans la noticeUniversité ou école supérieure
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Instituto de Geociencias pays non établi dans la noticeStructure de recherche
Faculdade UnB Planaltina — Universidade de Brasília, Instituto de Biofísica Carlos Chagas Filho (IBCCF) — Universidade Federal do Rio de Janeiro et Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, avec 2 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.