Telomere length as a genomic biomarker for assessing microplastic-induced damage in farmed gilthead sea bream

Microplastics are widespread pollutants in aquatic environments and pose significant risks to aquatic organisms, including species vital to aquaculture. The gilthead sea bream, extensively farmed in the Mediterranean, is frequently exposed to these contaminants, leading to potential long-term health consequences. Telomere length, a reliable marker of genomic integrity and cellular aging, offers a promising approach for assessing the biological effects of environmental stressors like microplastics. This study investigates the impact of microplastic exposure on telomere length in gilthead sea bream, evaluating its potential as a genomic biomarker for detecting microplastic-induced damage. Juvenile sea breams were divided into three groups: a control group and two experimental groups exposed to relatively low (25 mg/kg b.w./day) and high (250 mg/kg b.w./day) doses of polystyrene microplastics for 21 days. Telomere length was measured using qPCR, and statistical analyses were conducted to compare the T/S ratio between the groups. The results showed significantly shorter telomeres in fish exposed to both low and high doses of polystyrene microplastics compared to controls, with a clear dose-dependent effect (p < 0.05). These findings indicate that microplastic exposure compromises genomic stability in gilthead sea bream, supporting the use of telomere length as a rapid and sensitive biomarker for environmental monitoring in aquaculture. The study highlights the potential of telomere length as a valuable tool for evaluating fish health in polluted environments, contributing to the development of sustainable practices in aquaculture.