Bioaccumulation and translocation of organophosphate esters in a Mangrove Nature Reserve from the Pearl River Estuary, South China

Little is known about the distribution and bioaccumulation of organophosphate esters (OPEs) in mangrove ecosystems. In this study, water, sediments, plants and animals were collected from Qi'ao Island Mangrove Nature Reserve to investigate the levels, bioaccumulation and biomagnification of OPEs. Concentrations of sigma OPEs in the mangrove plant Sonneratia apetala (an exotic species) were greater than those in Kandelia obovata (a native species). Translocation factors of OPEs in the two mangrove tree species were greater than 1, indicating that OPEs were mainly absorbed in aboveground tissues. Concentrations of OPEs in mangrove trees and animals were negatively correlated with their log Kow, suggesting that accumulation of OPEs in mangrove biota was influenced by hydrophobicity. A significant difference for concentrations of sigma OPEs was found among the eight mangrove animal species. Concentrations of sigma OPEs in mangrove animals were related with lipid contents, feeding habits and Kow of OPEs. Biota-sediment accumulation factor of OPEs was larger than 1, suggesting that bioaccumulation of OPEs occurred in mangrove animals. The targeted OPEs except isodecyl diphenyl phosphate were not biomagnified in mangrove animals. This study highlights bioaccumulation of OPEs in mangrove biota and suggests further concern about the ecological risk of OPEs to mangrove biota.

Automated summary

This study investigates the distribution and bioaccumulation of organophosphate esters (OPEs) in mangrove ecosystems. It was found that OPEs were mainly absorbed in aboveground tissues of mangrove plants and their concentrations in mangrove animals were related to lipid contents, feeding habits, and hydrophobicity of OPEs. The study highlights the bioaccumulation risk of OPEs in mangrove biota.