Multisampling Strategies for Determining Contaminants of Emerging Concern (CECs) in the Marine Environment

The determination of contaminants of emerging concern (CECs) in the marine environment is performed through many different sampling approaches. Therefore, the main objective of this study was to compare different existing sampling strategies: biofilm mesocosms, considering micro- and macrofouling; passive sampling; and grab marine water. The sampling of grab water was performed considering spatial and time-line variations. The spatial analysis of CECs showed that three sun agents and caffeine represent the biggest proportion of CECs in the Malaga Mediterranean coastal area, ranging from 0.391 to 0.495 ng/L. The time-line analysis did not show any upward or downward trend in CEC concentration. The mesocosm study comprised a separate evaluation of micro- and macrofouling that showed similar profiles, in which the sun agents presented the highest concentrations. While certain compounds were detected at comparable levels in both fouling types, such as clotrimazole around 0.001 ng/L, others exhibited significant differences in concentration, like caffeine. The passive sampling was also performed, obtaining similar results to those observed in the biofilm mesocosm macrofouling. Finally, all the obtained results from the different samplings were statistically compared, showing that passive sampling presented greater similarities with macrofouling and that there are significant differences between the sampling approach employed.