Presence, risk assessment, and priority pollutants determination of antifouling paint biocides in Istanbul Beylikduzu Marina, Sea of Marmara, Türkiye

Abstract

Antifouling chemicals are mainly used on water-contact surfaces to prevent biofouling formation on ships or submarine hulls. This study focuses on examining the presence of antifouling paint biocides (Irgarol 1051, chlorothalonil, and dichlofluanid) in the seawater of Beylikduzu Marina, Istanbul, and includes an assessment of their environmental risks. Surface seawater samples were collected from six stations around the marina in the spring, summer, autumn, and winter of 2023. The collected water samples were processed using both liquid-liquid extraction and stir bar sorptive extraction methods, and analyses were carried out using gas chromatography-mass spectrometry. Wilcoxon and Bland-Altman tests confirmed the higher efficiency of stir bar sorptive extraction. The highest concentrations of chlorothalonil, dichlofluanid, and Irgarol 1051 were determined as <MDL, 0.16 µg/L, and 0.24 µg/L, respectively, by liquid-liquid extraction method, while the highest concentrations of these compounds were measured as 0.5 µg/L, 0.81 µg/L, and 1.57 µg/L, respectively, by magnetic stir bar extraction method. One-way analysis of variance (ANOVA) showed no significant seasonal variation in biocide concentrations, while regression analysis suggested a limited influence of water quality parameters, particularly for Irgarol 1051. Hierarchical cluster analysis grouped stations based on biocide concentrations, linking M2-M3 to boat mooring, M5-M4 to restricted circulation, M1 to maintenance, and M6 to external influences, emphasizing the role of anthropogenic and hydrodynamic factors in biocide distribution. The risk assessment indicates that the examined antifouling biocides may pose a threat to aquatic life. Irgarol 1051, in particular, requires attention due to its significant risk quotients.