Εvaluatiοn of the biοlοgic effects of an aluminium-based galvanic anοde on marine organisms

• Main Author: Levallois, Alexandre
• Other Authors: Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Normandie Université, Antoine-Laurent Serpentini
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2023
• Subjects: Galvanic anode; Zinc; Aluminium; Bioaccumulation; Metal cocktail; Oyster; Abalone; Algae; Anode galvanique; Cocktail de métaux; Huître; [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry; Molecular Biology/Molecular biology; Crassostrea gigas; Pacific oyster
• Online Access: https://theses.hal.science/tel-04104705; https://theses.hal.science/tel-04104705/document; https://theses.hal.science/tel-04104705/file/sygal_fusion_60573-levallois-alexandre_646dc9be43624.pdf

The installation of offshore structures (e.g., wind farms, ship hulls and propellers, port infrastructures.) involves the use of corrosion protection systems. Among them, galvanic anode cathodic protection (GACP) using plates made of a metal alloy, often aluminium and zinc, is one of the most practiced methods. The oxidation of the anode induces a release of metal ions or oxyhydroxides into the marine environment, leading to a potential enrichment of aluminium and zinc concentrations in the water column and in the sediment near the galvanic anodes. The objective of this thesis work was to study the effects of dissolution of an aluminium-based galvanic anode on marine organisms of different taxonomic groups and trophic levels. Experiments under controlled conditions were conducted on 9 species including the Pacific oyster, Crassostrea gigas, the European abalone, Haliotis tuberculata, 4 species of microalgae, 3 species of macroalgae as well as on the microphytobenthos. The different organisms tested showed a large difference in sensitivity to the cocktail of aluminium and zinc produced by the galvanic anodes. The microphytobenthos was impacted from aluminium concentrations that are regularly reported in the environment, while the development of oyster larvae was compromised for aluminium concentrations slightly above the environmental maximums. Under representative environmental conditions, no effect of galvanic anodes on the health of adult oysters and juvenile and adult abalone was observed. Only significantly higher concentrations induced alterations in the lysosomal system and energy metabolism as well as growth retardation. Most of the photosynthetic organisms tested, both macro- and microalgae, were found to be relatively resistant to metals with few or no effects observed on algal growth and photosynthesis. This work increases our knowledge of the impact of galvanic anodes on marine species, particularly on groups of organisms that were previously rarely considered in ecotoxicological studies on aluminium ...