First evidence of meso- and microplastics on the mangrove leaves ingested by herbivorous snails and induced transcriptional responses

Chao Fang; Ronghui Zheng; Fukun Hong; Shunyang Chen; Guangcheng Chen; Min Zhang; Fulong Gao; Jincan Chen; Jun Bo

doi:10.1016/j.scitotenv.2022.161240

First evidence of meso- and microplastics on the mangrove leaves ingested by herbivorous snails and induced transcriptional responses

Sci Total Environ. 2023 Mar 20:865:161240. doi: 10.1016/j.scitotenv.2022.161240. Epub 2022 Dec 29.

Authors

Chao Fang¹, Ronghui Zheng², Fukun Hong², Shunyang Chen¹, Guangcheng Chen¹, Min Zhang², Fulong Gao², Jincan Chen³, Jun Bo⁴

Affiliations

¹ Laboratory of Marine Biodiversity, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China; Observation and Research Station of Coastal Wetland Ecosystem in Beibu Gulf, Ministry of Natural Resources, Beihai 536015, China.
² Laboratory of Marine Biodiversity, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China.
³ Laboratory of Marine Biodiversity, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China; State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Sciences, Xiamen University, Xiamen 361102, China.
⁴ Laboratory of Marine Biodiversity, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China. Electronic address: bojun@tio.org.cn.

PMID: 36587672
DOI: 10.1016/j.scitotenv.2022.161240

Abstract

Although evidence suggests the ubiquity of meso- and microplastics (MMPs) in mangrove forests, our knowledge of their bioavailability and risk on mangrove leaves is scarce. Here, we investigated MMP contamination concerning submerged mangrove leaves and herbivorous snails that mainly feed on them from the four mangrove forests located in Beibu Gulf, Guangxi Province, China. Results showed that the MMP abundance on the mangrove leaves ranged from 0.01 ± 0.00 to 0.42 ± 0.15 items cm^-2, while it ranged from 0.33 ± 0.21 to 6.20 ± 2.91 items individual^-1 in the snails. There were significant positive correlations between snails and leaves regarding the abundance of total MMPs and the proportions of MMPs with the same characteristics. Expanded polystyrene (EPS) that mainly derived from aquaculture rafts, accounted for a major component both on the leaves and in the snails in Shi Jiao (SJ). Both the detection frequency and percentage of larger EPS (2.00-17.50 mm) on the leaves in SJ were higher than other sites. Meanwhile, the detection frequency, abundance and percentage of larger EPS on the leaves had significant positive correlations with those of micro-EPS in the snails. These findings suggested that mangrove leaves may represent a viable pathway for MMPs to enter the herbivorous snails. Larger EPS with higher frequency of occurrence on mangrove leaves were more likely to be encountered and ingested by snail considering its opportunistic feeding behavior. In addition, 11 sensitive genes involved in the processes of metabolism, intestinal mucosal immune systems, and cellular transduction in the snails were significantly suppressed by MMP exposure, which may be potentially used as early biomarkers to indicate the biological effects of MMPs under realistic environmental conditions. Overall, this study provides novel insights into the fate, sources, and biological effects of MMPs on mangrove leaves.

Keywords: Biological effects; Biomarkers; Expanded polystyrene; Herbivorous snail; Mangrove leaves.

MeSH terms

China
Environmental Monitoring / methods
Microplastics*
Plastics*
Polystyrenes / analysis
Wetlands

Substances

Microplastics
Plastics
Polystyrenes