Mangrove soil: A potential contamination source to estuarine ecosystems of Australia

Abstract

Mangrove vegetation is widely distributed around the Australian coast. However, the potential hazard of mangrove soil as a contamination source to estuarine ecosystems has received insufficient recognition. The processes associated with estuarine ecological degradation due to contamination by toxic substances from buried and actual mangrove soils consist of three steps: (1) pyritization of mangrove soils; (2) sulphurification of pyrite and (3) toxification of pH-dependent elements. Australia is characterized by stable coasts which favour the accumulation of pyrite in mangrove inhabited intertidal zones. Results achieved so far show that Australian (buried) mangrove soils contain greater potential sulphuric acidity than those developing in rapidly prograding coasts. This implies that a sever threat to estuarine ecosystems may exist if these potential contamination sources are not managed properly.