Bioaccumulation and speciation of arsenic in plankton from tropical soda lakes along a salinity gradient

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Viana, Jose Lucas Martins ; Steffler, Debora Aparecida ; Hernandez, Amauris Hechavarria ; Costa, Juliana dos Santos ; Pellegrinetti, Thierry Alexandre ; de Jesus, Erick Christian Rodrigues ; Cancian, Marianna ; Fiore, Marli Fatima ; Rezende-Filho, Ary T. ; Sussulini, Alessandra ; Barbiero, Laurent ; Menegario, Amauri Antonio ; Fostier, Anne Helene

• Document type: Journal article
• Source: Science of The Total Environment; v. 895, p. 11-pg., 2023-07-03.

Abstract

Uptake and transformation of arsenic (As) by living organisms can alter its distribution and biogeochemical cycles in the environment. Although well known for its toxicity, several aspects of As accumulation and biological transformation by field species are still little explored. In this study, the bioaccumulation and speciation of As in phytoplankton and zooplankton from five soda lakes in the Brazilian Pantanal wetland were studied. Such lakes exhibited contrasting biogeochemical characteristics along an environmental gradient. Additionally, the influence of contrasting climatic events was assessed by collecting samples during an exceptional drought in 2017 and a flood in 2018. Total As (AsTot) content and speciation were determined using spectrometric techniques, while a suspect screening of organoarsenicals in plankton samples was carried out by high-resolution mass spectrometry. Results showed that AsTot content ranged from 16.9 to 62.0 mg kg-1 during the dry period and from 2.4 to 12.3 mg kg-1 during the wet period. The bioconcentration and bioaccumulation factors (BCF and BAF) in phytoplankton and zooplankton were found to be highly dependent on the lake typology, which is influenced by an ongoing evapoconcentration process in the region. Eutrophic and As-enriched lakes exhibited the lowest BCF and BAF values, possibly due to the formation of non-labile As complexes with organic matter or limited uptake of As by plankton caused by high salinity stress. The season played a decisive role in the results, as significantly higher BCF and BAF values were observed during the flooding event when the concentration of dissolved As in water was low. The diversity of As species was found to be dependent on the lake typology and on the resident biological community, cyanobacteria being responsible for a significant portion of As metabolism. Arsenosugars and their degradation products were detected in both phytoplankton and zooplankton, providing evidence for previously reported detoxification pathways. Although no biomagnification pattern was observed, the diet seemed to be an important exposure pathway for zooplankton. (AU)

• FAPESP's process: 17/12644-0 - Microbial communities and functional genes involved in nutrient cycling in Nhecolândia Wetlands (MS)
• Grantee: Thierry Alexandre Pellegrinetti
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 19/18124-4 - Fluxes, speciation and bioavailability of arsenic at the water/sediment interface in alkaline lakes of the Pantanal of Nhecolândia using DGT
• Grantee: José Lucas Martins Viana
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 16/14227-5 - Climatic changes and environmental impacts in wetlands of Pantanal region (Brazil): quantification, control factors and long term temporal modeling
• Grantee: Adolpho José Melfi
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants
• FAPESP's process: 17/23301-7 - Soil and surface water alkaline systems in the Nhecolândia, Pantanal: Hydro-biogeochemical functions
• Grantee: Janaina Braga do Carmo
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• FAPESP's process: 21/05927-1 - Speciation, bioaccumulation and biotransformation of arsenic by cyanobacteria (Arthrospira sp. and Anabaenopsis sp.) from the saline-alkaline lakes of the Pantanal of Nhecolândia
• Grantee: Marianna Alves Cancian
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 21/05683-5 - Influence of hydrological conditions on the availability of arsenic in alkaline lakes of the Pantanal of Nhecolândia
• Grantee: Debora Aparecida Steffler
• Support Opportunities: Scholarships in Brazil - Scientific Initiation