Comments: Disaster on a Global Scale
1st June 2009
I read with dismay the article in Saturday's Advertiser "Disaster on a
Global Scale". Particularly worrying was the statement by Environment and
Heritage CEO, Allan Holmes:
"The science says it may be best to bioremediate than let in seawater. It
could do more damage if we let in seawater".
What "science" is he referring to? Could it be that promulgated by the
well-meaning, but ill-informed groups who advocate a fresh water solution at
all costs? As a retired aquatic biology scientist, I am aware of quite a
few other reputable scientists who believe that the solution to the present
crisis is to open the barrages to the sea, and let the system return to an
estuarine condition, the natural state before the barrages were built. Far
from causing damage, this would stop the further development of acid
sulphate soils which are now reaching crisis levels. As well, a new,
fluctuating marine/freshwater system would develop to include seagrass
meadows supporting fish nurseries, and migratory birds etc. Our Ramsar
obligations would then be modified to accommodate the changed wetland
ecology (www.ramsar.org). This is a far cry from the total destruction of
virtually all living things in the system if the lakes continue to acidify.
There is not enough fresh water to mitigate this, and it is irresponsible to
allow the little that we do have to spread over the lakes surface and
Bioremediation and liming of the vast lakes area is slow and expensive, and
would likely not work in the longer term, since it would only treat the top
few cm of soil. The sediments containing sulphides are metres deep, just
waiting to oxidise to sulphuric acid should the plants die from salinity,
high temperatures, lack of rainfall, or even the acid itself. The
production of lime is very greenhouse unfriendly, since it involves the
heating of limestone to release carbon dioxide, leaving the calcium oxide
Your own editorial in the same edition mentioned CSIRO work indicating that
the seawater solution is the only practical one available; however, I
disagree that it would be a disaster for freshwater plants and animals.
These would migrate or decrease naturally, and be replaced by salt-tolerant
species, of which there are numerous examples existing right now around the
lakes. Just think of the Gippsland lakes as examples of what could happen.
To be so heavily influenced by certain groups which are particularly vocal,
this government could be shooting itself in the foot if the present trends
continue. I ask them to consider what will happen to the vines in places
like Langhorne Creek when they are covered with toxic, acidic dust blown in
from the surface of the dry lake beds?