Devenir et interactions du Hg et du Se chez les poissons : comparaison entre les espèces d'aquaculture et les espèces sauvages (Amazonie)

Hg and Se fate and interactions in fish: comparing aquaculture and wild (Amazon) species

• Auteur / Autrice : Marianna Alves cancian
• Direction : Zoyne Pedrero zayas, David Amouroux
• Type : Projet de thèse
• Discipline(s) : Chimie analytique
• Date : Inscription en doctorat le 26/03/2024
• Etablissement(s) : Pau
• Ecole(s) doctorale(s) : Sciences Exactes et leurs Applications
• Partenaire(s) de recherche : Laboratoire : Institut des sciences analytiques et de Physico-chimie pour l'Environnement et les Matériaux

Mots clés

Mots clés libres

Mercure

Sélénium

Spéciation

Poisson

Mercury

Selenium

Speciation

Isotopic signature

Résumé

Methyl-mercury(Hg) hazardous effects are biomagnified through the trophic chain, resulting in serious social, environmental and human health effects. The role of selenium (Se) as antagonist of Hg has been largely evoked but their fate and interaction mechanisms remain unknown. Fish and seafood are considered the main source of Hg for humans. Most of the studies carried out correspond to aquatic species from marine environments without paying attention to freshwater ones. In marine species, Hg and Se bioaccumulation trends reveal an increase of their levels with the trophic position. Nevertheless, in fresh water ecosystems as the Amazon river, the trend for Se bioaccumulation is not elucidated. Tracking bioaccumulation pathways of Se (and Hg) in fish from the Amazon region is of primary relevance. Amazon riverside populations exhibit singular eating habits, where fish is essential in their diet, representing 80% of the dietary protein source. This thesis will provide new insights on Se and Hg fate and interactions in fish. The chemical species of these two elements will be identified and tracked in key organs such as muscle, brain, liver and kidney of animals from controlled feeding experiments and Amazonian river ecosystems (at different positions in the trophic chain). The isotopic signature of Hg (and/or Se) will be exploited to answer questions raised by speciation studies concerning its bioaccumulation and interaction.