Coastal zones are economically vital but are increasingly threatened by potential toxic elements pollution. Despite hosting a national fishing port and intensive mariculture, Dongping town, still lacks a detailed study focusing on PTEs contamination in its coastal area. This study investigated eight PTEs (As, Cd, Cr, Cu, Hg, Ni, Pb, Zn) in 26 sediments and 45 seawater samples from Dongping in wet (July) and dry (December) seasons. Hg was consistently high in seawater in both seasons with means of 0.62 μg/L in July (0.39-0.85) and 0.49 μg/L in December (0.21-0.97), and exceeded GB Class IV limit at 83% and 33% sites, respectively, with heavy CF contamination in both seasons. HPI classified all July samples in poor or very poor category. In sediments, July showed severe contamination by As (mean CF = 6.18; Igeo Class 2-3) and Hg (mean CF = 5.26; Igeo Class 1-3) but As declined in December (CF = 0.5) meanwhile Hg persisted (mean CF = 3.58). NPI indicated moderate contamination in December sediments but serious pollution at all July sites. Hakanson RI averaged 321 (July) and 180 (December), with Hg contributing 64% and 79% of total risk. BCR identified Cd as most labile (34.6% average; 83% sites at high risk) and Zn (mean 22.7%), whereas Hg was mainly residual (F4 = 88.9%). Spearman Correlation, PCA, and HCA linked Cu-Ni-Zn to ship maintenance/dry-dock activities, Cd to agricultural runoff, PbCr to electroplating effluents, and Hg to atmospheric deposition.