In the Australian state of New South Wales, the removal of dead fish from the Darling River has begun. Last week there was a mass killing of them, once again in the same river in several years. The current event in the Menindee area is explained by low oxygen levels and hot weather. The services ensure that water quality is constantly monitored and say that “there is no need for concern”.
According to the website of the Australian public broadcaster ABC, “millions of decomposing fish have washed down the Darling River in the Menindee area in recent days.” An emergency management center was set up on Sunday in the small town about 1,000 kilometers west of Sydney to coordinate river cleanup and water quality monitoring under the supervision of the NSW Police. Police said it would probably not be possible to remove all the dead fish, and that efforts would be focused on “areas of high density”.
Brett Greentree of the state police department described the operation as “very demanding” and added that it was “unprecedented” in terms of the number of fish killed.
Causes of mass extinction
Environmental authorities say low oxygen levels in the river contributed to the massive fish deaths. The heat made the situation worse. On Sunday, the temperature in the region reached 40 degrees Celsius. The event is also linked to a “significantly increased number of fish”, which happened as a result of the floodwaters receding.
A police statement on Sunday said “the release of higher quality water is continuing where possible to increase dissolved oxygen levels” in the river.
Community organization OzFish is working to save as many surviving fish as possible from the river. Its representative, Braeden Lampard, described the smell in the river area as “putrid”. Activists estimate that about 85 percent of the dead fish are native species, and the rest are individuals belonging to alien species, including carp.
The services calm down
Menindee residents demanded that the authorities take swift action regarding the pollution of the river. “We rely 100 percent on this river for our domestic use,” Karen Page told Australian public broadcaster ABC.
The authorities assure that the water supplied to households is still of “high quality”. They reassure that in this area “there is no cause for concern”.
However, Joy Becker, a marine animal specialist at the University of Sydney, warned that it would take “a significant amount of time” to restore the river’s ecosystem to its pre-fish kill state. ‘Fish populations may not recover quickly or in the same numbers,’ he said. He added that large numbers of pests can take up residence in these places, which “makes it even more difficult for the fish to return.”
Another such case
The Darling is the second longest river in Australia, stretching for 2,739 kilometers. Similar events have recently occurred in 2019 and 2018. In total, up to a million fish have died due to poor flow, poor water quality and sudden changes in temperature.
According to ecologists, the river is polluted, and uncontrolled drainage of water from it for irrigation of fields worsens the situation. The local indigenous people protest against the degradation of the reservoir.
ABC.net.au, BBC, Reuters, tvnmeteo.pl
Main photo source: PAP/EPA/SAMARA ANDERSON