Occurrence, spatial distribution, and source implications of phenolic compounds, phthalate esters, and perfluoroalkyl substances in surface seawater of Laizhou Bay, a typical fishery ecosystem in the Bohai Sea, China.

Abstract

Laizhou Bay is an important spawning and nursery ground for fishery species in the Bohai Sea, yet the spatial patterns of emerging endocrine disrupting chemicals (EDCs) in its surface seawater and their connection to industrial activities in the surrounding watersheds remain unclear. In the present study, 4 phenolic compounds, 7 phthalate esters (PAEs), and 11 perfluoroalkyl substances (PFAS) were concurrently quantified at 25 stations across the bay. Total phenolic, PAE, and PFAS concentrations ranged from 0.05 to 0.92 μg/L, below detection to 1.12 μg/L, and below detection to 0.21 μg/L, respectively. Phenolic compounds and PAEs were concentrated near the Yellow River estuary, whereas PFAS peaked near the Xiaoqing River estuary and adjacent smaller rivers. Bisphenol A exhibited its highest concentrations near the Mihe, Bailang, and Yuhe River estuaries, likely reflecting urban and industrial inputs from the Weifang area and rapid removal from the dissolved phase in the sediment-laden Yellow River plume. This spatial divergence reflects the differing industrial geography of the contributing watersheds. Phenols and PAEs originate from diffuse sources along the densely populated Yellow River corridor, while PFAS are linked to fluorochemical manufacturing facilities concentrated in the Xiaoqing basin. The low PFAS concentrations in the Yellow River estuary further suggest that contaminant loads are driven by specific industrial sectors rather than by river discharge volume. These findings indicate that effective pollution control in fishery ecosystems requires strategies matched to the source characteristics of different pollutants, rather than uniform regulatory measures.