Unseen pollutants: Microplastics in deep-sea invertebrates.

Microplastics (MPs) are a growing concern in marine ecosystems, but data on their presence in deep-sea environments remain limited. This study investigates MP contamination in nine deep-sea invertebrate species collected from the Gulf of Orosei (Central eastern Sardinia, Italy) at depths of 250-450 m. A total of 105 MP particles were identified in 89 % of specimens from three phyla (Arthropoda, Echinodermata, and Mollusca). Filaments and fragments were the dominant shapes, while polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET) were the most common polymers. Cluster analysis indicated that MP contamination patterns were driven more by ecological traits than by taxonomy. These findings provide the first evidence of MP presence among different species of deep-sea invertebrates from the Gulf of Orosei and highlight the importance of species-specific ecological characteristics in understanding MP distribution and accumulation in deep-sea ecosystems.