After the Apocalypse
Sitting on top of Mount
Hotham David could see the horizon in all directions.
As far as the eye could see, 1.3 million hectares had
been burnt. In places the fire had been so hot it had
split boulders and burnt every living thing to the water
line, in others the tops of the trees were still intact
although the leaves were brown. It had been the understorey
that had burned.
Some streams still had
some green foliage along the edges but others were bare
and the trees were skeletonised sticks where fire had
been so hot as to consume the green branches of the
tops of trees.
The EPA provided us with
a photo of a tidal wave of sludge that was passing down
the Ovens River after the first rain fell after the
fire. This thick sludge of ash and mud was the consistency
of custard. That same weekend it claimed the life of
a volunteer fire fighter who drowned when her vehicle
was washed over a river crossing. The survival of any
fish or other gill-breathing organisms was doomed.
The heat generated by the
fires raised the oxygen losses and water temperatures
killing most of the inhabitants of the streams. Assuming
the life expectancy of fish is five years (some live
longer) this means that five-year classes of fish have
been lost to the fire in affected streams. From tiny
fingerlings to three pounders, all sizes have been lost.
Some fish have survived.
It is a fact that a few fish managed to make it through.
Retreating to cold spots in the river bed or wherever
they could reach spring fed water that remained cool
enough to keep them alive as the fire raged around them.
Some fish are now being
recruited from dams and storages where the urge to spawn
will bring them back into some of the fire affected
streams. Nevertheless the losses have been a significant
blow to the populations of fish that had already been
adversely affected by prolonged drought.
A five-year generational
gap exists in the fishery. Natural recruitment will
be low, as erosion, siltation and the suffocation of
spawning beds by ash will prevent good natural recruitment
for at least two years until the scouring effect of
winter floods cleans the gravels and silts to allow
The release of alkalinity
by the ash will first have a caustic effect on our generally
acidic streams neutralising and finally creating a burst
of growth in the macrophytes (waterplants) and the macro
invertebrates (insect) populations. Abundance will return
with the recycling of nutrient from the fires back into
Trees and plants are re-colonising
the ash beds and exposed soils and binding them together
with new growth. Unfortunately this takes time for recovery
to take effect. It may be two or three years.
What of the effect on our
human population? Like the wild life that survived the
fire many of them have been profoundly affected. Tourism
has died. Positive efforts are being made to try to
revive confidence but many businesses in the fire ravaged
areas will not survive.
The state Government has
allocated $2 MIL for immediate relief but four shires
in the fire-affected regions have lost a total of $121
MIL of economic activity as a result. This will need
much time to address.
My concern is to address
the fish populations first. Then economic recovery will
follow more quickly. The loss of five year classes of
fish can be addressed by a restocking process of yearlings.
These will thrive in the developing, nutrient rich environment
and plus the gaps caused the fire in the first year
of low recruitment.
If governments were to
provide this restocking program it would short-circuit
the drawn out recovery process. A positive message that
they were proactively intervening to assist the recovery
would inspire the return of recreational anglers to
our streams and help repair damaged rural economies.
After all, when you are
travelling on a fishing trip and you buy a burger in
Bairnsdale and fill up with fuel in Maffra or pop into
the blue duck for a beer, you are having a profound
effect on the recovery of recreational angling tourism
in the regional areas of Victoria.
~ Geoff Hall