I’ve been up the Murray in South Australia, on a research trip for my new novel. Am only home briefly, and will be going back up the river again in a few days. It’s been a marvellous and enlightening experience. First, a few facts. The Murray is the third longest navigable river in the world, after the Amazon and Nile, stretching 2,520 kilometres from its source to the sea. The mighty Murray-Darling basin is the third largest water catchment on earth. During my trip this grandeur was very much on show – the river remains stunningly beautiful. But the Murray faces many threats today, and these were on show as well. I was surprised at just how in-your-face the river’s problems are, in South Australia at least. Take the levees. Hundreds of kilometres of levee banks were built after World War One to ‘reclaim’ wetlands for soldier settlers. The once fertile river flats either side soon turned into dry wastelands. The farmers gave up, but the levees remain, protecting a dead landscape from life-giving floods.
European Carp (actually from Asia) are another example. Old-timers remember a crystal clear river, abounding in aquatic plants, brim-full of Murray Cod and Perch. Millions of carp have actually changed the colour of the river, from clear to muddy. They hoover up the bottom and banks, sucking up water weeds, roots and all, then discharging sediments through their gills. The few plants that survive this treatment, still die because sunlight can no longer penetrate the cloudy water. Native fish and herbivorous water birds such as ducks, swans and spoonbills, have nothing to eat. There were no swans at Swan Reach when I was there. Only pelicans and other fish eating birds, which are thankfully making a small dent in carp numbers.
Problems go on and on. The most common trees along the Murray aren’t River Red Gums anymore, but English willows. They were planted along the river to mark its course, during the early years when the natural flood plain extended many square kilometres. Willows choke banks and channels, out-competing native species. They cause algal blooms by dropping leaves in autumn. And they are thirsty trees along an even thirstier river. CSIRO research shows an extra five and a half megalitres of water per year could be returned to the system for every hectare of willow canopy removed! And every drop counts in a country like ours. Incredibly, in the last twenty years the Marne River, (once a major contributor of water to the Murray) has completely dried up, due to dams in the Barossa Valley.
The Murray River has a mysterious allure. As far back as 65 million years ago, it was flowing westwards from the Great Dividing Range. Yet in a mere 200 years we have caused so much damage to this beautiful and ancient wonder of the world. Let’s hope Australia can work together to protect the Murray-Darling basin, truly the lifeblood of eastern Australia. In the meantime, I can’t wait to head back on up the river …