Oxidative stress and metabolic responses of Litopenaeus vannamei to magnetic fields from simulated submarine cables in offshore wind farms

To evaluate the impact of submarine cable magnetic fields from offshore wind farms on marine organisms, we used Litopenaeus vannamei juveniles (Body mass ca. 3 g, 30 individuals per exposure group and control group) and adults (Body mass ca. 25 g, 30 individuals per group) as experimental subjects to conduct a 14-day magnetic field (0.2 mT) exposure experiment. First, we observed the post-exposure, morphological changes in the hepatopancreas of juveniles, then performed an exposure experiment on adults under the same conditions to assess antioxidant enzyme activity in the hepatopancreas, and to analyze differential metabolites in both hepatopancreas and muscle tissues using non-targeted metabolomics technology. Results show that magnetic field exposure led to albino damage of the hepatopancreas of juveniles. Compared with the control group, the 0.2 mT group showed a significant decrease in superoxide dismutase (SOD) activity in the hepatopancreas of adults, an increase in glutathione peroxidase (GSH-Px) activity and a decrease in malondialdehyde (MDA) concentration. KEGG enrichment analysis reveals that differentially expressed metabolites in the hepatopancreas were primarily enriched in purine metabolism, phenylalanine metabolism, and arachidonic acid (AA) metabolism pathways, whereas those in muscle tissue were significantly associated with ABC transporters, amino acid biosynthesis, and neuroactive ligand-receptor interactions. In the hepatopancreas of adults, D-xylonic acid, guanosine monophosphate (GMP), adenosine 5'-monophosphate (AMP), cytidine 5'-monophosphate (CMP), uridine monophosphate (UMP) and leukotriene C₄ were upregulated. In contrast, succinate and L-threonic acid were downregulated. In muscle cells, astaxanthin was upregulated, AA and its derivatives 2-arachidonoyl glycerol (2-AG) and N-arachidonoyl dopamine (NADA) were downregulated, and taurine, D-malic acid, and D-erythrose 4-phosphate were significantly downregulated. The results reveal the molecular responses of magnetic field exposure to energy metabolism, oxidative defense, and inflammatory response in L. vannamei, providing basic data for assessing the impact of magnetic fields of submarine cables in wind farms on marine life.