Microplastic ingestion and phthalate esters bioaccumulation in yellowfin tuna (Thunnus albacares): tissue-specific distribution across gills, stomach, and muscles.

This study investigates the contamination of phthalate esters (PAEs) and microplastics (MPs) in yellowfin tuna (Thunnus albacares) collected from the southern coast of Kaohsiung, Taiwan. Results revealed significantly higher PAE concentrations in red muscle tissue (2595-72,734 ng/g ww), with DiNP, DnBP, and DEHP as the dominant compounds, compared to lower levels in white muscle (271.98-811.49 ng/g ww). Specifically, the stomach (92 particles) contained a higher number of MP particles compared to the gill (56 particles). Fibrous rayon dominated in the gills, likely due to water filtration, while polypropylene and polyolefin fragments were prevalent in the stomach, suggesting ingestion of plastic debris. Most MPs measured 1-2 mm in size and were blue or transparent, indicating textile and film-based sources. Principal component analysis showed that bioaccumulation patterns were associated with the hydrophobicity and molecular weight of PAEs. These highlight improved marine pollution controls to safeguard ecological and human health.