Investigation of microplastic presence in the intestinal and muscle tissues of wild and farmed gilthead sea bream (Sparus aurata)

Abstract

The occurrence of microplastics in gilthead sea bream (Sparus aurata) was comparatively investigated under different rearing conditions (farmed and wild) and across seasons (summer and winter). A total of 172 fish were analyzed for microplastics in muscle tissue and intestines. Microplastics were separated using a 10% potassium hydroxide (KOH) digestion protocol, and polymer types were identified via ATR FT-IR spectroscopy. Suspicious particles in the meat samples were smaller and more suitable for measurement with the μ-FT-IR device, and therefore could not be detected. In terms of microplastics in the intestines, the number of positive fish in the wild group during the winter period was significantly higher (p<0.05) compared to the farm group. The MP/Fish Count in the wild samples during the winter period (1.23±0.17) was significantly higher than in the summer (0.61±0.10) and winter (0.37±0.11) farm groups (p<0.05). The average amount of microplastics was 0.52 microplastics/fish in farmed samples and 0.94 microplastics/fish in wild samples. Two types of plastics were identified: polystyrene and polyethylene. This study contributes to the literature by providing important and comparative data on microplastic contamination in gilthead sea bream from aquaculture and wild environments in Turkish waters.