Rare earth elements in seagrass beds: Contamination, bioaccumulation, and biomonitoring

Shanshan Chen; Zhenghua Tao; Xinqing Zheng; Fengyuan Chen; Li Zhang; Shiquan Chen; Ke Pan

doi:10.1016/j.jhazmat.2025.138271

Rare earth elements in seagrass beds: Contamination, bioaccumulation, and biomonitoring

J Hazard Mater. 2025 Jul 15:492:138271. doi: 10.1016/j.jhazmat.2025.138271. Epub 2025 Apr 11.

Authors

Shanshan Chen¹, Zhenghua Tao², Xinqing Zheng³, Fengyuan Chen¹, Li Zhang⁴, Shiquan Chen⁵, Ke Pan⁶

Affiliations

¹ Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China.
² Beijing Key Laboratory for Risk Modeling and Remediation of Contaminated Sites, Beijing Municipal Research Institute of Eco-Environmental Protection, Beijing 100037, China.
³ Key Laboratory of Marine Ecology Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China.
⁴ Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572000, China.
⁵ Hainan Academy of Ocean and Fisheries Sciences, Haikou 570125, China; Dongzhaigang, Conservation and Restoration of Seagrass Bed Resources, Hainan Observation and Research Station, Haikou 570125, China. Electronic address: chensq@hnhky.cn.
⁶ Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China. Electronic address: panke@szu.edu.cn.

PMID: 40239517
DOI: 10.1016/j.jhazmat.2025.138271

Abstract

Coastal environments are increasingly vulnerable to contamination from rare earth elements (REE) due to expanding anthropogenic activities, yet the fate and ecological risks of REE in ecologically critical seagrass ecosystems remain poorly understood. This study deciphered the behavior, fractionation, and compartmentalization of REE in both seagrass sediments and tissues. Total REE concentrations in sediments ranged from 70.5 to 258.8 mg kg^-1, with Ce emerging as the most enriched REE in both matrices. Pollution Load Index varied from 0.7 to 3.0, indicating slight to moderate REE pollution, with localized enrichment of some REE (e.g., Tb, Lu) pointing to anthropogenic influences such as industrial effluents and marine traffic. Principal component and enrichment factor analyses attribute approximately 66 % of REE patterns to geogenic weathering, while 22.6 % reflect anthropogenic contributions. Geochemical partitioning revealed that Fe-Mn oxides serve as major REE sinks, while organic matter plays a dual role-enhancing total REE retention through complexation yet reducing mobility by stabilizing labile fractions. Correlations between REE concentrations in seagrass tissues and sediments suggest species-specific uptake and limited translocation. These findings underscore the capacity of seagrasses to serve as sensitive bioindicators for REE pollution and highlight the importance of organic matter and rhizosphere processes in modulating REE bioavailability.

Keywords: Biomonitoring; Eu anomaly; REE fractionation; Seagrass.

MeSH terms

Bioaccumulation
Biological Monitoring
Environmental Monitoring
Geologic Sediments / analysis
Geologic Sediments / chemistry
Metals, Rare Earth* / analysis
Metals, Rare Earth* / metabolism
Water Pollutants, Chemical* / analysis
Water Pollutants, Chemical* / metabolism

Substances

Metals, Rare Earth
Water Pollutants, Chemical