In Australia, the severe heat wave causes a mass extinction of fish

In Australia the severe heat wave causes a mass extinction

Millions of dead fish continue to surface in Australia’s Darling River. A slaughter caused by the low levels of oxygen in this river and the very high temperatures, above 40°C, in this region in recent days. The phenomenon is on an unparalleled scale but not unprecedented for the small town of Menindee, where the management of water by the authorities is a subject of debate.

A scorching temperature and an abnormally low level of oxygen in the river: this is the cocktail that has almost instantly killed millions of fish in south-eastern Australia in recent days. Their carcasses continue in places to completely cover the river.

The vast majority are bony bream, a species known to proliferate in times of flood – the region where they were found fell victim to it a short time ago – then to die en masse soon after. But in such proportions, it is unheard of.

The weather is certainly unforgiving in this region. Already in 2019, the drought had killed nearly a million fish there. But in this watershed, the largest in Australia, economic interests are also immense, and sources of tension. It is thus abundantly exploited by cotton producers, whose activity, according to their opponents, causes the rivers downstream to dry up, and without any real intervention from the public authorities.

In the meantime, the thermometer in the region will remain above 30°C until next Saturday.

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