Are Chinese mitten crabs (Eriocheir sinensis) suitable as biomonitor or bioindicator of per- and polyfluoroalkyl substances (PFAS) pollution?

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous in the environment. In Flanders, the bioaccumulation in aquatic organisms is currently being monitored using European perch and European eel. Since both are native species, there is an ethical need to search for other suitable biomonitors. This study aims to investigate whether the invasive Chinese mitten crab could be used in biomonitoring programs by assessing PFAS accumulation in hepatopancreas, muscle tissue, and carapace. Furthermore, we correlated accumulated concentrations to those in the local abiotic environment. Concentrations in the crabs (highest average n-ary sumation PFAS concentration of 688 +/- 505 ng/g ww) were often higher than those in crab species from other regions across the globe, confirming that Flanders is highly polluted with PFAS. Concentrations in the crabs did not reflect those in the abiotic environment. This implies that biomonitoring is necessary to investigate the impact of PFAS pollution on organisms in aquatic ecosystems, as important data is missing when only the abiotic environment is monitored. The accumulation profiles differed between the invasive crab and the native European perch and European eel, potentially due to a different ecology and trophic position. Since all three species provide complementary information on the PFAS pollution, a multi-species approach in biomonitoring is recommended. Overall, our results show that the crabs can be used as biomonitor, but more information is necessary to confirm their suitability as bioindicator.

Automated summary

This study investigates the potential use of Chinese mitten crabs as biomonitoring organisms for per- and polyfluoroalkyl substances (PFAS). The study finds that PFAS concentrations in crabs from Flanders are often higher than those in other regions, indicating high pollution levels in the area. The accumulation profiles of PFAS also differ between the invasive crab and native European perch and European eel, suggesting the need for a multi-species approach in biomonitoring. More information is needed to confirm the suitability of crabs as bioindicators.