Coastal wetlands trap plastics from terrestrial and marine sources, but the stocks of plastics and their impacts on coastal wetlands are poorly known. We evaluated the stocks, fate, and biological and biogeochemical effects of plastics in coastal wetlands with plastic abundance data from 112 studies. The representative abundance of plastics that occurs in coastal wetland sediments and is ingested by marine animals reaches 156.7 and 98.3 items kg-1, respectively, 200 times higher than that (0.43 items kg-1) in the water column. Plastics are more abundant in mangrove forests and tidal marshes than in tidal flats and seagrass meadows. The variation in plastic abundance is related to climatic and geographic zones, seasons, and population density or plastic waste management. The abundance of plastics ingested by pelagic and demersal fish increases with fish length and dry weight. The dominant characteristics of plastics ingested by marine animals are correlated with those found in coastal wetland sediments. Microplastics exert negative effects on biota abundance and mangrove survival but positive effects on sediment nutrients, leaf drop, and carbon emission. We highlight that plastic pollution is widespread in coastal wetlands and actions are urged to include microplastics in ecosystem health and degradation assessment.
Bibliographical noteKAUST Repository Item: Exported on 2022-02-01
Acknowledgements: The authors thank three anonymous reviewers and the handling editor for their comments on improving the initial version of the manuscript. X.O. is supported by an Impact Postdoctoral Fellowship awarded by The Chinese University of Hong Kong to S.Y.L., and a Postdoctoral Fellowship at The Chinese University of Hong Kong. N.F.-Y.T. is supported by the National Natural Science Foundation of China (Grant Number 41976161). S.C. is supported by the Environmental and Conservation Fund, Hong Kong Government (Grant Number ECF 101/2019)
ASJC Scopus subject areas
- Environmental Chemistry