Some Redlands Coast residents living close to mangrove wetlands are experiencing the annual ‘pong-a-thon’.
While the rotten egg smell is often mistaken for sewage, it is the result of a natural process when mangroves drop seeds which are broken down by bacteria living in the soil.
It occurs annually between May and November and Redland City Council often receives reports about the smell from areas in Thorneside, Thornlands and Victoria Point.
Queensland Health has previously advised Council and residents that there are no long-term health impacts associated with exposure to hydrogen sulphide odours produced by mangrove seeds breaking down, as the levels are well below those known to cause health effects.
Council’s Principal Adviser (Community Education) Ranger Stacey Thomson said mangrove wetlands and swamps played an essential environmental role on Redlands Coast.
“Mangroves assist in nutrient cycling and provide a habitat for spawning and juvenile fish, prawns and crabs as well as vital roosting and feeding areas for migratory birds,” she said.
“They also help to stabilise our coastline, reducing erosion from sea currents, tides and waves.
“So while they may be ‘on the nose’ at some times of the year, they are well and truly environmental heroes.”
Mangrove odour can intensify with:
- time of the year, usually May to November
- seasonal rainfall and tides – high tides disperse organic matter closer to residential areas
- wind direction and speed influences where and how fast the odour is dispersed
- more mangrove seeds means more organic matter breaking down
