Organophosphate pesticides sequestered in tissues of a seagrass species- Zostera capensis from a polluted watershed

Organophosphate pesticides (OPPs) are persistent in the environment, but little information is available on their bioaccumulation in seagrass. In this study, the seagrass - Zostera capensis was collected from Swartkops Estuary in South Africa to investigate the bioaccumulation of OPPs from contaminated sediments and the water column. This plant was chosen because it grows abundantly in the estuary's intertidal zone, making it a viable phytoremediator in the urban environment. Extraction was performed by the QuEChERS method followed by GC-MS analysis. The mean concentration of n-ary sumation OPPs ranged from 0.01 to 0.03 mu g/L for surface water; 6.20-13.35 mu g/ kg dw for deep-rooted sediments; 18.79-37.75 mu g/kg dw for leaf tissues and 12.14-39.80 mu g/kg dw for root tissues of Z. capensis. The biota-sediment accumulation factors (BSAFs) were greater than one, indicating the potential for Z. capensis to bioaccumulate and intercept the targeted pesticides. A weak insignificant correlation observed between log BSAFs and log Kow indicates that the bioaccumulation of OPPs in tissues of Z. capensis were not dependent on the Kow. Eight of the selected pesticides had root-leaf translocation factors (TFr-l) greater than 1, indicating that Z. capensis can transport these chemicals from roots to leaves. The results from this study implies that this plant species can clean up OPP contamination in the environment.

Automated summary

The study found that Zostera capensis has the potential to absorb and intercept targeted pesticides in contaminated environments, therefore playing a role in cleaning up organophosphate pesticide contamination in the environment.