Physiological reactions of large yellow croaker (Larimichthys crocea) to sound stimulus at 500 Hz: Implications for marine management regarding low frequency continuous noise

Abstract

With increasing in human activities such as the operation of offshore wind farms and shipping, the impacts of anthropogenic low frequency continuous noise on marine organisms have garnered increasing attention. This study used the sound-sensitive large yellow croaker (Larimichthys crocea) to investigate the physiological effects of low frequency continuous noise. Fish were exposed to continuous underwater noise at sound pressure levels of 105 ± 5 dB, 125 ± 5 dB, and 145 ± 5 dB for 15 days, with an unexposed control group. Antioxidant enzyme activities in the liver were measured, and transcriptome sequencing was performed to screen for noise stress-related differentially expressed genes. Results showed that superoxide dismutase (SOD) activity peaked under low noise stress but decreased significantly under high noise stress. Glutathione peroxidase (GSH-Px) activity decreased initially and then increased, reaching the highest level under high noise stress. Catalase (CAT) activity was highest under medium noise stress and similar to the control under high noise stress. Transcriptome analysis revealed that noise stress altered gene expression in the brain and liver, with differentially expressed genes significantly enriched in pathways related to neural function, apoptosis, metabolism, immunity, and signal transduction. Key genes in glutamatergic and GABAergic synapse pathways were downregulated, while caspase family genes in apoptosis pathways were upregulated. Genes related to pancreatic secretion and fatty acid metabolism were downregulated, and those in complement and chemokine signaling pathways were altered. The study suggests that continuous exposure to underwater noise from human activities generates excessive reactive oxygen species in L. crocea, disrupting the normal function of the antioxidant enzyme system. High-intensity noise may exceed its antioxidant defense capacity and potentially lead to neurologic damage, accelerated apoptosis, metabolic disorders, and compromised immune function in L. crocea. These findings provide a basis for the impact assessment of anthropogenic low frequency continuous noise on fishery resources.