Field study of the microplastic pollution in sea snails (Ellobium chinense) from mangrove forest and their relationships with microplastics in water/sediment located on the north of Beibu Gulf

Laboratory studies demonstrated that the mussels were good model organisms in revealing microplastics (MPs) uptake and toxicity. However, only limited field study data on the MPs in benthic marine mesoherbivores collected from mangrove forests are currently available. In this study, the MPs in the snails (Ellobium chinense) organs, rather than the shell, from a mangrove forest were dominant fraction (maximum reaching to 60%). Unexpectedly, no significant linear relationships were found between the levels of MPs in the organs of the snails and the levels in the sediment/tidal water. Further studies were done to explore the sources of the MPs in snail organs. MPs in snail organs at both the landward (interior) and seaward (exterior) zones mainly origin from the pore water. Moreover, the MPs found in the snails showed no relevance to the particulate matter (PM) collected from pore water. The findings reported here imply that both the MPs and PM in pore water affect the extent of MPs enter into the organs of benthic marine mesoherbivores collected from mangrove forest. [Display omitted] •MPs were firstly detected in the snail (Ellobium chinense) of mangrove forest.•Large number of MPs enter into the snail organs rather than adsorbed onto the shell.•Positive relationship was obtained between MPs in snail organs and pore water.•MPs in the snail organs were irrelevant to particulate matter in pore water. The main finding of the study: Pore water may be the main environmental medium for the ingestion of MPs by snails in both the landward and seaward zones of the mangrove forest.