Why is Australia evacuating its rivers?

According to the Old Testament, Noah built an ark because there was too much rain. In Australia they’re building one because there hasn’t been enough.

Following a series of extreme heatwaves and lack of rain, New South Wales a faces a "potential fish Armageddon", according to NSW Minister for Agriculture Adam Marshall who has just approved a $6.8 million fish restocking programme.

Jumping in with both feet

Earlier this year, at the height of the Australian summer, around a million fish were found dead in the Darling River, in NSW. Their deaths were caused by a combination of heatwave conditions – drought, falling river levels and algal blooms that starved the water of oxygen.

The decomposing fish further worsened the situation by polluting the river even more. Eventually, a 40km stretch of the Darling had to be cleared of their remains.

To safeguard fish populations in the Darling River, such as the Murray Cod, the Trout Cod and the Golden Perch, the NSW state government is rescuing fish from the affected areas to house them in safe, sustainable conditions until the rivers are once again inhabitable.

Work to get the waterways ready involves artificial aeration, oxygenation and chemical treatments to improve water quality, plus the allocation of more people to the grim task of rapidly removing dead fish in the event of further mass deaths.

Can’t stand the heat

Extreme heat is becoming increasingly common in Australia. Between 1951 and 1980, “very high monthly maximum temperatures” occurred around 2% of the time. But between 2003–2017, they were seen 12% of the time, according to the Bureau of Meteorology

“We’re expecting temperatures over 40ºC ... so once again I’d encourage everyone to take the risk of heat related illness seriously,” NSW Health’s Director of Environmental Health, Dr Richard Broome, said in January.

During last summer’s heat waves even elite athletes were affected, with Andrea Petkovic collapsing during her first-round match at the Australian Open tennis tournament, and the Tour Down Under cycle race being shortened by almost 30km due to the heat.