Spatial and temporal organic and heavy metal pollution at Mai Po Marshes Nature Reserve, Hong Kong

Y. Liang, Ming Hung WONG*

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

90 Citations (Scopus)


An intensive monthly sampling of water and sediments from 12 sites over 8 months covering wet and dry seasons at Mai Po Marshes Nature Reserve was conducted during June 1997-February 1998. Major organic (C, N and P) and heavy metal pollutants (Cd, Cr, Cu, Ni, Pb, Zn) water and sediment samples were examined. The results showed that Mai Po Marshes were severely polluted by organic matter and heavy metals, and the water from Deep Bay appeared to be the source of pollution. Up to 13-55% chance that the sediments of Mai Po Marshes were classified as moderately to seriously metal contaminated materials, according to the guideline set by Hong Kong Government. Empirical models describing organic matter and heavy metal spatial and seasonal dynamics in the water and sediments were formulated, based on data analysis. During wet season (June-October), more than 58% variations of total P can be explained by ortho-P in water, while ammonia-N explained up to 90% variations of total Kjeldahl nitrogen in water. Throughout the whole sampling period (June-February), there were significant correlations (p < 0.01) between total organic C in water. pH in the sediments and salinity in water appeared to be important factors determining heavy metal mobility in sediments, while potential metal release from the sediments is a concern when any oxidizing processes such as flooding or dredging are imposed on sediments.

Original languageEnglish
Pages (from-to)1647-1658
Number of pages12
Issue number9
Publication statusPublished - Sept 2003

Scopus Subject Areas

  • Environmental Engineering
  • Environmental Chemistry
  • Chemistry(all)
  • Pollution
  • Health, Toxicology and Mutagenesis

User-Defined Keywords

  • Biological conservation
  • Heavy metals
  • Organic pollution
  • RAMSAR site
  • Wetland


Dive into the research topics of 'Spatial and temporal organic and heavy metal pollution at Mai Po Marshes Nature Reserve, Hong Kong'. Together they form a unique fingerprint.

Cite this