Geoff Helisma |
The pungent smell that greets drivers as they cross the Oyster Channel Bridge has been mystifying Yamba residents over the past week.
A July 10 post on the Yamba Notice Board Facebook site – ‘what is the absolutely putrid smell driving out of Yamba tonight … smells sooo bad – had attracted 104 comments by the Independent’s editorial deadline (noon on Monday), with various theories expressed.
One person posted, “I would imagine it’s from the recent rain”.
Yamba received 43mm of rain over the previous week, according to the Bureau of Meteorology.
Other theories and observations included: “It’s that bad I actually nearly vomited. Something dead somewhere;
“I think I saw a dead roo there over a week ago but with all the rain we had the smell went into overdrive lol;
“Maybe rotting grass from the rain; It’s usually all the swampy water lying around the mangroves. And stagnant water sitting in the drains;
“I think it’s the horrible gassy smell the mangroves give off.
“Smells like sewer, awful;
“It’s an overflow of human effluent!! I’m actually serious and it has been travelling down river for weeks it’s putrid and has and will make many more ill;
“As far back as 40-45 years ago when there was no development around the lake area, that type of smell was there used to call it Od-cologne swamp; Mangrove smell.
“There has been mega crop of fruit on mangroves which have dropped off the trees and they are decomposing giving off the odour. Same happening in The Tweed at the moment … natural thing.”
The Independent asked Clarence Valley Council if it knew the source of the odour, citing a recent Tweed Shire Council media release, which said, “It’s not a sewage spill; it’s the odour of decomposing mangrove fruit.
“The source of the smell is fruit dropped by mangroves, which produces hydrogen sulphide gas when decomposing – the same ‘rotten egg’ gas which is given off by sewage.
“Grey mangroves drop fruit at this time of year….
“The factors which cause the odours to become so strong at certain times are not clear, but would be related to tide, rainfall, the amount of fruit dropped in the season, frequency of tidal flushing and wind strength and direction.
“This is a natural process….”
Clarence Valley Council acknowledged that mangrove fruit was “quite possibly” the source of the smell.
“There were some extra high tides also recently that may have perched water in places that it does not normally sit,” a CVC spokesperson said in an emailed response.
“The smell could be associated with rotting vegetation in those areas, now that the tides aren’t so high the water is not exchanging [and] refreshing.”