Acid fish kill disaster coming to Mandurah?.

Acid fish kill disaster coming.

We should be totally ashamed of ourselves for wanting to deprive canal residents of the wonderful technicolour experiences like in this photo at Eastport canals at Port Bouvard just in the name of protecting fish and protecting biodiversity.

This is due to acid groundwater seeping through canal walls The bright orange material is probably an iron mineral called schwertmannite that is mixed up with some algal scum.

The more vivid the orange colour the greater the stored acidity and toxicity of the material.

The beautiful blue-green streaks are due to a precipitate of aluminum hydroxide forming due to the reaction of acid groundwater with alkaline seawater - both soluble Aluminium and fresh Aluminium hydroxide precipitate are almost instant death for anything with gills.

If you disliked fish and wanted a bream and fish killer chemical, this is the stuff to bottle and sell.

The next stage in the saga is for sulfate reducing bacteria to convert the iron oxides into iron monosulfides so the sea bottom get covered with the wonderful slimy black gunk that we have come to love so well.

Unfortunately, all the phosphorous that was happily stuck on the iron oxides gets thrown back into the water column as the monosulfides form.

Our canal dwellers will probably get the experience of putrid black muck coexisting with toxic algal blooms. When you put a sulfuric acid leach through a soil column you get humungously high phosphorus and nitrogen concentrations just from the breakdown of organic matter, even before you start loading up the system with fertiliser.

So rush out and buy a little piece of paradise tommorrow.

But let your politicians know this is happening and ask them what they are doing about this.

Hon Mark McGowan MLA Minister for the Environment 20th Floor, 197 St George's Terrace Perth 6000 e-Mail: Phone ( 08 ) 9222 9111 Fax ( 08 ) 9222 9410

Premier of WA , Hon Alan Carpenter MLA 197 St George's Terrace, Perth 6000 e-Mail: Phone ( 08 ) 9222 9888 Fax: ( 08 ) 9322 1213



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Adam Gallash's picture

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Mon, 2006-05-01 12:48

Looks nice, don't think I'll go for a swim. So how do they fix this one Terry or can't they?


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Wed, 2006-05-03 18:27

Is that photo representative of the entire Port Bouvard Development at Eastport?

I think not!

The flow thru the Mandurah cut is immense!

The water in those canals is replaced many times over every 12 hurs just from the push thru the cut!

It's not a "normal" up and down 2/3 meter on springs tide situation IMHO - like you might find elsewhere!

The amount of Eastrary water going in and out MUSt be in the many hundreds of millions f gallons an hour!

The draw and push effect that has on the canals system is huge...such that waters completely exchanged many times a day!

I believe those canals are not complete - i.e area's are still blocked off while they build the last sot of triangle canal shaped bit based on what I saw there a day or so ago!

I suspect that, if you hunted around in there to a bit of temporarily stagnant water behind the blocked off sections to hold the water back while they construct, you might find whats depicted, but I don't believe thatphoto is at all representative of what Terrys portraying as some massive fish kill disater about to occur!

My offer to tery is this - i'll gladly ferry him around the entire Bouvards canals at my expense with his camera to get a realistic idea of the extent of the problem if any beyond what I suspect this to be (isolated) based on what I've seen!

He can document it fully and quantify it and explore any causal factors etc!

At least lets get a andle on it rather than decrying a many multi million $ development based on one photo!

I havent noticed the problem Terry alludes to on the sort of scale he alludes too in his post!

There are definitely huge cidity problems in the canals homes sands but the water quality there is from what I've seen pretty bloody amazingly good due to the huge diurnal exchange rate!
Heck - it's so good I was thinking of trying to get a lease on all the under jetty spaces to farm black pearl oyster! ;o)

I think a closer loosk warranted myself before we bleat unnecessarily about something that may be just turn out to be a temporary "pea in a pizzpot" while they are constructing!!