The seeds of life

The salt lake harsh and lifeless
Glitters white hot in the sun
A wasteland free of life stress
Until the day is done


But hidden in the salt crust
Waiting for a storm
Are tiny seeds of life dust
That one day will be born

And finally there comes a time
A day of salt lake dreaming
When tiny shrimp of brine
Fill the flooded lake all teeming

The water birds are gobbling
And shrieking while they feed
And over partners squabbling
As they seek a mate to breed

When you look at an apparently lifeless salt lake glittering in the harsh summer sun under a cloudless sun bleached sky it is difficult to envisage an environment less amenable to life. And yet there, embedded in the salt crust, are tiny almost invisible brine shrimp eggs or cysts waiting for the rain. These small brown cysts measuring about 200 microns in diameter are almost fully dehydrated and will remain viable for decades. There they lie, dormant in suspended animation until the day it rains. When the rains come and the salt crust dissolves tiny microalgae living in the salt and the underlying mud of the salt lake begin to reproduce rapidly turning the brine into a green organic soup. The brine shrimp cysts draw in water through their permeable shells and when fully hydrated begin to hatch. Within 24 hours the newly hatched brine shrimp begin to feed on the green soup and grow rapidly. They then begin to reproduce and the salt lake becomes thick with brine shrimp. And not just brine shrimp. The cysts of many other species of small molluscs and crustacea that were also dormant in the salt quickly join the party. In barely no time, the previously lifeless salt lake is a seething sea of life. And then the birds arrive in their countless thousands to feast on the sea of plenty and to breed. Ducks and pelicans are joined by migratory wading birds from as far away as Siberia in a magnificent spectacle of abundant life. And then when the party is over and the lake dries out the seeds of life again remain dormant in the salt crust until the next rain.

It is easy to overlook the immense ecological importance of salt lakes to bird life in particular and in their own right.

Tears of Salt

Blurred skeleton trees
Ring the salt lake all shimmering
Shades of life memories
Through the long summer simmering

Gone now the sweet water
And green leafiness
A lamb to the slaughter
The price of progress

Uncontrolled clearing
For sheep and for wheat
Replace kangaroo spearing
And wild bush treats

Wounded land crying
In great tears of salt
Wounded land dying
From farming assault

How quickly things change! In less than 100 years Lake Ninan has transformed from a sweet lake with water fresh enough for steam train boilers into a dazzling white salt lake. The lake was the water supply for Wongan Hills as recently as the 1930’s. Today, the skeletons of ancient trees killed by rising salt levels ring the lake and shimmer eerily in the heat haze reflecting off the salt. A stark testament to the consequences of over-clearing!

The matted shallow roots of the native vegetation once inhibited rain-water infiltration into the soil and ensured that fresh rain water flowed into streams and river systems and that water tables remained low. When this vegetation was removed for broad acre wheat and sheep farming, rates of infiltration increased greatly. This caused saline ground-water to rise to the surface and salt to concentrate in the surface soil. Rain-fall run-off into streams became increasingly saline and large tracts of previously arable land became salt-affected. In the case of Lake Ninan the now salty Mortlock River delivered millions of tonnes of salt into the once fresh lake. Dry land salinity is a major problem for both agriculture and biodiversity across Western Australia’s wheat belt which is one of the world’s biodiversity “hot spots.”

One solution is to return native vegetation to over-cleared farm-land but this is not easy in soil that is now salt affected and can no longer support the growth of salt sensitive plant species. Another option is to physically lower water tables using bore drains carved into the hillsides. Both strategies are now being applied with some effect across Western Australia’s wheat belt. And if things weren’t difficult enough already there is the added problem of climate change and a significantly drier climate to contend with.