Full Title
Acidification of Murray River Wetlands
Contact Person
Darren Baldwin or Gavin Rees
Project Team
Karina Hall, Adam Richardson
Funding Body
NSW Murray Wetlands Working Group
Duration
completed February 2006
Outcomes
Hall, K., Baldwin, D.S, Rees, G.N. and Richardson, A. (2006). Distribution of Sulfidic Sediments in Wetlands along the Murray River. Report prepared for the NSW Murray Wetlands Working Group, February, 29pp.
Summary
Acid sulfate sediments form naturally when soils with significant iron content are inundated for extended periods by sulfate-rich waters (generally saline waters). Under oxygen free (anoxic) conditions and with a plentiful supply of organic matter, certain bacteria can reduce sulfate to sulphide, which reacts with metals to form minerals such as pyrite. If left undisturbed in oxygen free conditions, the sulfidic sediments cause no harm.
However, if the sediments are subsequently drained and exposed to air, the sulfides can rapidly oxidise to form sulfuric acid (battery acid), which may flush into adjacent water bodies or streams. The acidic water can cause significant environmental damage and harm fish and other plants and animals including stock. Thirty wetlands along the Murray River from Lake Hume to the South Australian border have been sampled to assess their potential for producing acidic events.
