Spatial and seasonal metal variation, bioaccumulation and biomonitoring potential of halophytes from littoral zones of the Karachi Coast | JoVE Visualize

Spatial and seasonal metal variation, bioaccumulation and biomonitoring potential of halophytes from littoral zones of the Karachi Coast

Amtul Mujeeb¹, Irfan Aziz¹, Muhammad Zaheer Ahmed¹

¹Dr. Muhammad Ajmal Khan Institute of Sustainable Halophyte Utilization, University of Karachi, Karachi 75270, Pakistan.

The Science of the Total Environment|March 30, 2021

View abstract on PubMed

Summary

Coastal halophytes show potential for phytoremediation of trace metals like lead and zinc. Specific species demonstrated seasonal metal accumulation, indicating their use in cleaning polluted Karachi coastal soils.

Area of Science:

Environmental Science
Ecology
Bioremediation

Background:

Coastal wetlands act as natural sinks for trace metals.
Phytoremediation using halophytes is globally recognized.
Limited data exists on trace metal accumulation in Karachi coast halophytes' harvestable parts.

Purpose of the Study:

To assess the phytoremediation potential of six Karachi coast halophytes for Mn, Zn, Pb, and Cr.
To investigate seasonal and spatial variations in soil and plant metal concentrations.
To identify specific halophyte species for effective metal cleanup.

Main Methods:

Six halophyte species (A. lagopoides, A. macrostachyum, A. stocksii, A. marina, C. cretica, S. fruticosa) were studied.
Seasonal (winter, pre-monsoon summer, post-monsoon summer) and spatial (Sandspit, Do-Dariya/Clifton, Korangi creek) sampling.
Analysis of trace metal (Mn, Zn, Pb, Cr) concentrations in soil and plant shoots.

Main Results:

A. stocksii showed high Pb accumulation (16 mg kg⁻¹) at Sandspit.
C. cretica was a key candidate for Zn phytoremediation (96 mg kg⁻¹) at Sandspit.
A. lagopoides exhibited significant Mn and Cr accumulation, acting as a bioindicator across sites and seasons.

Conclusions:

Halophytes on the Karachi coast possess phytoremediation capabilities for Pb, Zn, Mn, and Cr.
Metal bioaccumulation is species-specific and seasonally influenced.
A. stocksii, C. cretica, and A. lagopoides show promise for targeted phytoremediation strategies.

Keywords: