Editor's Note: This blog was originally published January 28, 2019.
We’ve seen many results of drought in the US over the last several years, from dwindling water supplies to more frequent and intense wildfires to dust problems. In Australia, drought seems to be the cause, at least indirectly, of another type of problem: eutrophication and lots and lots of dead fish.
In the Darling River in New South Wales, hundreds of thousands of fish have suddenly died this week—the third time in just a few months that such a thing has happened. Officials believe warm weather (it’s summer in the Southern Hemisphere, of course) has spurred large algae blooms, which then quickly died off and deprived the river of much of its oxygen—hence the dead fish.
As this article reports, some are also saying the problem could have been avoided, at least in part, with better water management—specifically, by restricting the amount of water farmers are allowed to take from the river for irrigation.
In an attempt to oxygenate the water, the government of New South Wales has put solar-powered aerators in place around the region, but that hasn’t been enough to solve the problem.
In addition to threatening the food supply for parts of Australia—about a third of the country’s food is grown in the Murray-Darling River Basin—the algae blooms and dead fish are hurting tourism. A river cruise operator quoted in the article says, “This is probably the last fish kill we’ll have, because there’s nothing left to kill.”