Occurrence, bioaccumulation, and ecological risk assessment of contaminants of emerging concern using native and invasive species as biomonitors

Traditionally, contaminants of emerging concern (CECs) monitoring have focused on assessing their occurrence in abiotic compartments and in native fish species. The use of non-native species in environmental quality studies has recently proven to be a key tool for evaluating the CECs exposure and their ecological risks. In this study, the use of different native and invasive species was proposed to assess the environmental quality of a coastal Mediterranean wetland. A biomonitoring assessment was conducted at ten locations within the Albufera Natural Park (Spain), including irrigation channels, the lake, and the artificial wetland. The bioaccumulation of 171 CECs was evaluated in the Asian clam, the American red swamp crayfish, and the pumpkinseed sunfish, which are primary invasive species in this ecosystem. Furthermore, a comparative analysis was done with the native clam to verify whether invasive species could provide equivalent information. A total of 35 CECs were detected in at least one of the species analyzed. The Asian clam exhibited the highest number of detected compounds (23), as well as the highest chemical concentrations, particularly for pharmaceuticals. The ecological risk assessment performed with internal concentrations of CECs also pointed at the Asian clam as the most suitable species for chemical biomonitoring in this area. The compounds that had the highest contribution to the calculated ecological risk were sertraline, fluoxetine, terbuthylazine, caffeine, and oseltamivir. At most exposure sites HI values revealed high risk, indicating strong pressure from mixtures of CEs for both native and invasive species. This study shows that the analysis of chemical concentrations in invasive species can be considered a complementary tool to determine the ecological status of coastal wetlands.