• Transition from exposure- to trophic-driven accumulation along estuary-sea gradient. • PFMOAA show noncanonical accumulate pattern deviated from chain-length-dependent trend. • Bioaccumulation ability of long-chained PFAS tended to increase with trophic level. • Short-chained PFAS showed downward trend from invertebrates transferred to fishes. • Demersal organisms showed more to ΣPFAS than that of pelagic biotas. Emerging global pollutants such as perfluoroalkyl ether carboxylic acids (PFECAs) pose increasing stress to estuary-bay-coastal ecosystems, yet the mechanisms governing spatial variability in Per- and Polyfluoroalkyl Substances (PFAS) bioaccumulation remain poorly understood. Here, PFAS characteristics were compared across 342 aquatic species spanning 30°N-40°N in China, and Structural Equation Modeling (SEM) was applied to identify dominant drivers at a broad spatial scale. This study provided the first attempt to integrate geographical, ecological, and anthropogenic gradients to elucidate large-scale variability in PFAS bioaccumulation mechanisms. Mean ΣPFAS concentrations (ng/g dw) in organisms decreased by more than two orders of magnitude from estuary to open sea-estuary (2138.9) > Laizhou Bay (146.2) > Bohai Sea (22.9) > Yellow Sea (13.1) > Northern East China Sea (10.5)-demonstrating a sharp decreasing trend with increasing distance from the estuary. Demersal species exhibited higher ΣPFAS burdens than pelagic organisms, reflecting differences in ecological niche, feeding habits, prey source, body morphology and exposure routes (aqueous, sedimentary, dietary). The relative proportions of HFPO-TrA, PFMOAA, and PFOA declined seaward, while C9-C14PFCAs and PFOS increased correspondingly. PFMOAA showed non-canonical accumulation pattern deviated from chain-length-dependent trend. Bioaccumulation potential strengthened with trophic position for long-chain PFAS, whereas short-chain analogues exhibited an attenuation trend from benthic invertebrates transferred to fishes. SEM results revealed a mechanistic transition from exposure-controlled accumulation in estuary to trophic-driven magnification in offshore regions. The elevated dietary risks associated with seafood consumption, particularly within estuary-bay areas, highlight the urgent need for monitoring and targeted management of emerging PFECAs in marine ecosystems.
Li et al. (Wed,) studied this question.