The study was carried out in Gokceada, located in the North Aegean Sea in 2017, during winter and summer seasons and the concentrations of 16 polycyclic aromatic hydrocarbon (PAH) components were determined inP. oceanicatype seagrass samples. Total PAH (TPAH) values ranged from 190.8 to 7668.7 ng g(-1)dw during the sampling period. In addition, the source of pollution was investigated by using PAH ratios. According to the fluoranthene (FA) /pyrene (PY) ratio in the winter period, the origin of pollution is mostly pyrolytic, while in the summer period, according to the fluoranthene (FA) /pyrene (PY) and benzo(a)anthracene (BaA) /chrysene (CHR) ratio, the pollution origin was found to be petrogenic.