Exploring mercury detoxification in fish: The role of selenium from tuna byproduct diets for sustainable aquaculture

• Published in: Journal of hazardous materials Vol. 480; p. 135779
• Main Authors: El Hanafi, Khouloud, Fernández-Bautista, Tamara, Ouerdane, Laurent, Corns, Warren T., Bueno, Maite, Fontagné-Dicharry, Stéphanie, Amouroux, David, Pedrero, Zoyne
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2024; Elsevier
• Subjects: Aquafeed; Chemical Sciences; Metallothionein; Methylmercury; Selenoneine; Speciation; Aquafeed; Speciation; Metallothionein; Selenoneine; Methylmercury; methylmercury; metallothionein; aquafeed; selenoneine; speciation
• DOI: 10.1016/j.jhazmat.2024.135779
• ISSN: 0304-3894; 1873-3336

Exposure to mercury (Hg) through fish consumption poses significant environmental and public health risks, given its status as one of the top ten hazardous chemicals. Aquaculture is expanding, driving a surge in demand for sustainable aquafeeds. Tuna byproducts, which are rich in protein, offer potential for aquafeed production, yet their use is challenged by the high content of heavy metals, particularly Hg. However, these byproducts also contain elevated levels of selenium (Se), which may counteract Hg adverse effects. This study examines the fate of dietary Hg and Se in an aquaculture model fish. Biomolecular speciation analyses through hyphenated analytical approaches were conducted on the water-soluble protein fraction of key organs of juvenile rainbow trout (Oncorhynchus mykiss) exposed to various combinations of Hg and Se species, including diets containing tuna byproducts, over a six-month period. The findings shed light on the dynamics of Hg and Se compounds in fish revealing potential Hg detoxification mechanisms through complexation with Hg-biomolecules, such as cysteine, glutathione, and metallothionein. Furthermore, the trophic transfer of selenoneine is demonstrated, revealing novel opportunities for sustainable aquafeed production. Understanding the interactions between Hg and Se in aquaculture systems is crucial for optimizing feed formulations and mitigating environmental risks. This research contributes to the broader goal of advancing sustainable practices in aquaculture while addressing food security challenges. [Display omitted] •New insights on the fate of dietary Hg exposure in fish.•Potential MeHg detoxification mechanism in fish model unveiled.•First time identification of MeHg-GSH in fish•Aquafeed sustainability enhanced by tuna byproducts.•First evidence of selenoneine trophic transfer in freshwater fish.