Eutrophication effects on CH4 and CO2 fluxes in a highly urbanized tropical reservoir (Southeast, Brazil)

Author(s)

Benassi, Roseli Frederigi ^[1] ; de Jesus, Tatiane Araujo ^[1] ; Gomes Coelho, Lucia Helena ^[1] ; Hanisch, Werner Siegfried ^[2] ; Domingues, Mercia Regina ^[1] ; Taniwaki, Ricardo Hideo ^[1] ; Goya Peduto, Thais Araujo ^[3] ; da Costa, Danilo Oliveira ^[3] ; Martins Pompeo, Marcelo Luiz ^{[4, 5]} ; Mitsch, William J. ^[6]

Affiliation

^[1] Fed Univ ABC, Ctr Engn Modeling & Appl Social Sci, Av Estados 5001, BR-09210580 Santo Andre, SP - Brazil

^[2] Univ Fed Sao Paulo, Dept Chem Engn, Sao Paulo - Brazil

^[3] Fed Univ ABC, Postgrad Program Environm Sci & Technol, CTA UFABC, Av Estados 5001, BR-09210580 Santo Andre, SP - Brazil

^[4] Univ Sao Paulo, Dept Ecol, Inst Biosci, Rua Matao, Trav 14, 321, POB 05508-900, Sao Paulo, SP - Brazil

^[5] UNESP, Postgrad Program Environm Sci, Campus Sorocaba, Sorocaba - Brazil

^[6] FGCU, Everglades Wetland Res Pk, Naples, FL - USA

• Document type: Journal article
• Source: Environmental Science and Pollution Research; v. 28, n. 31, p. 42261-42274, AUG 2021.
• Web of Science Citations: 0

Abstract

Shallow urban polluted reservoirs at tropical regions can be hotspots for CO2 and CH4 emissions. In this study, we investigated the relationships between eutrophication and GHG emissions in a highly urbanized tropical reservoir in Sao Paulo Metropolitan Area (Brazil). CO2 and CH4 fluxes and limnological variables (water and sediment) were collected at three sampling stations classified as hypereutrophic and eutrophic. Analysis of variance (ANOVA) and the principal component analysis (PCA) determined the most significant parameters to CO2 and CH4 fluxes. ANOVA showed significant differences of CO2 and CH4 fluxes between sampling stations with different trophic state. The hypereutrophic station showed higher mean fluxes for both CO2 and CH4 (5.43 +/- 1.04 and 0.325 +/- 0.167 g m(-2) d(-1), respectively) than the eutrophic stations (3.36 +/- 0.54 and 0.060 +/- 0.005 g m(-2) d(-1)). The PCA showed a strong relationship between nutrients in the water column (surface and bottom) and GHG fluxes. We concluded that GHG fluxes were higher whenever the trophic state increases as observed previously in temperate and tropical reservoirs. High concentrations of nutrients in the water column in the studied area support the high production of autotrophic biomass that, when sedimented, ends up serving as organic matter for CH4 producers. These outcomes reinforce the necessity of water quality improvement and eutrophication mitigation in highly urbanized reservoirs in tropical regions. (AU)

• FAPESP's process: 17/10355-1 - Relation between limnological variables (abiotic and biotic) and seasonality in CH4 and CO2 gas fluxes in the fluvial regions of the Billings and Guarapiranga dams (São Paulo - SP)
• Grantee: Roseli Frederigi Benassi
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/23767-1 - Relationship between limnological variables (abiotic and biotic) and seasonality in the flow of CH4 and CO2 gases in fluvial regions of the Billings and Guarapiranga dams (São Paulo - SP)
• Grantee: Joice Teixeira Silva Rodrigues
• Support Opportunities: Scholarships in Brazil - Technical Training Program - Technical Training