Microplastic ingestion in sea snakes: Examining age-related exposure and regional differences

This study presents the first published data on microplastic (MP) ingestion by sea snakes. The gastrointestinal tracts of 63 stranded sea snakes from six species along the Arabian Gulf and Gulf of Oman coasts in Sharjah, UAE, were examined: 39 Arabian Gulf Coral Reef Sea Snakes ( Hydrophis lapemoides ), 14 Yellow-bellied Sea Snakes ( Hydrophis platurus ), four Yellow Sea Snakes ( Hydrophis spiralis ), three Ornate Sea Snakes ( Hydrophis ornatus ), two Annulated Sea Snakes ( Hydrophis cyanocinctus ), and one Spine-bellied Sea Snake ( Hydrophis curtus ). MPs were detected in 95.3% of specimens, with an average concentration of 9.15 ± 1.47 MP/g. Additionally, 96.9% of the particles identified were fibers, primarily composed of nylon, suggesting wastewater discharge from domestic laundry as a potential source. The results show higher MP exposure among younger age classes and greater MP exposure in the Arabian Gulf compared to the Gulf of Oman. However, these differences were not statistically significant and might be artifacts of random variation rather than indicative of ecological trends. These patterns require further investigation with larger sample sizes. Additionally, no significant correlations were observed between microplastic concentrations and the levels of polycyclic aromatic hydrocarbons, organochlorine pesticides and heavy metals in different tissues of sea snakes. This study highlights MP contamination in sea snakes, shedding light on an overlooked taxon in marine plastic pollution research. • Objective: Investigate microplastic (MP) ingestion in sea snakes from Sharjah, UAE. • MPs detected in 95.3 % of specimens. 9.14 ± 1.47 MP g⁻¹ (wet weight). • Particle profile: 96.9 % fibers; polymer predominantly nylon. • Exposure pattern: juveniles > adults (not significant). • Regional pattern: Arabian Gulf > Gulf of Oman (not significant).