TY - JOUR
T1 - Potential impact of tide-regulation barriers on the formation of methylmercury in the Venice Lagoon (Italy)
AU - Pereira-Garcia, Carla
AU - Bravo, Andrea G.
AU - Cosio, Claudia
AU - Gallorini, Andrea
AU - Leoni, Simone
AU - Cassin, Daniele
AU - Guédron, Stéphane
AU - Adatte, Thierry
AU - Cabrera-Brufau, Miguel
AU - Sanchez, Olga
AU - Acinas, Silvia G.
AU - Amouroux, David
AU - Zonta, Roberto
AU - Dominik, Janusz
AU - Loizeau, Jean-Luc
N1 - Publisher Copyright:
© 2024 The Authors
PY - 2025/3/5
Y1 - 2025/3/5
N2 - Methylmercury (MeHg), a neurotoxic pollutant, is formed mainly under anaerobiosis. The “Modulo Sperimentale Elettromeccanico” (MOSE), built to temporarily close the Venice Lagoon and protect the city from flooding, induces changes in the hydrological regime, reducing water circulation and decreasing in the dissolved oxygen concentrations of the lagoon. Our study shows the potential changes in sediment and overlying water physico-chemistry in a simulated MOSE closing-event by incubating sediment cores for 48 h in the laboratory and deploying benthic chambers. In the incubated summer cores (September 2021), a significant increase in total Hg and MeHg concentrations in the water column was observed and associated with an increase in MeHg formation rates – particularly, MeHg formation rates doubled during the simulated MOSE-closing. This increase was associated to a release of dissolved organic carbon and to an enrichment of proteinaceous substances and reactive humic acids in the overlying waters. All these effects were not evident in late autumn (November 2019), when water temperature was 10 °C lower than in September 2021. Our study suggests that hydrological changes caused by the MOSE closure may in some periods increase MeHg concentrations within the Venice Lagoon.
AB - Methylmercury (MeHg), a neurotoxic pollutant, is formed mainly under anaerobiosis. The “Modulo Sperimentale Elettromeccanico” (MOSE), built to temporarily close the Venice Lagoon and protect the city from flooding, induces changes in the hydrological regime, reducing water circulation and decreasing in the dissolved oxygen concentrations of the lagoon. Our study shows the potential changes in sediment and overlying water physico-chemistry in a simulated MOSE closing-event by incubating sediment cores for 48 h in the laboratory and deploying benthic chambers. In the incubated summer cores (September 2021), a significant increase in total Hg and MeHg concentrations in the water column was observed and associated with an increase in MeHg formation rates – particularly, MeHg formation rates doubled during the simulated MOSE-closing. This increase was associated to a release of dissolved organic carbon and to an enrichment of proteinaceous substances and reactive humic acids in the overlying waters. All these effects were not evident in late autumn (November 2019), when water temperature was 10 °C lower than in September 2021. Our study suggests that hydrological changes caused by the MOSE closure may in some periods increase MeHg concentrations within the Venice Lagoon.
KW - MOSE
KW - MeHg formation
KW - Oxygen depletion
KW - Sediments
KW - Temperature
KW - Venice Lagoon
UR - http://www.scopus.com/inward/record.url?scp=85211328340&partnerID=8YFLogxK
UR - https://www.mendeley.com/catalogue/aa20ccbf-b884-3a40-8d36-daa3e44405e4/
U2 - 10.1016/j.jhazmat.2024.136747
DO - 10.1016/j.jhazmat.2024.136747
M3 - Article
SN - 0304-3894
VL - 485
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
M1 - 136747
ER -