Dead fish in Mulgrave River at Cairns being investigated by authorities

Hundreds of dead fish are floating on a popular Cairns river – and authorities can’t yet explain why. Find out more here.

A large number of dead fish in the Mulgrave River is causing alarm.

Local resident Jacob Davies said dead fish started appearing a week ago.

“In the last week we have seen an alarming number of dead fish in the river,” he said.

“The river stinks with the stench of them rotting.

“This is a beautiful river that is fished by many locals and enjoyed by tourists alike.

Dead fish, eels and crustaceans have been seen from the Dalton Bridge near Aloomba.

A Department of Environment and Science (DES) spokesman said there was a large number of dead fish about 4km downstream from Gordonvale.

Dead fish are appearing in the Mulgrave River and it is not clear why. Picture: supplied.

“DES officers have conducted site inspections and estimated hundreds of tilapia, barramundi, catfish, eels and shrimp had died,” he said.

DES officers conducted in situ water quality tests, took water samples and collected tissue samples from dead fish.

The fish and water samples will be analysed by a laboratory.

“The cause of the fish kill is unknown at this stage, however it could have been the result of low levels of dissolved oxygen in the water which can occur during periods of high water temperature and low river flows,” he said.

The Dulabed and Malanbarra Yidinji Aboriginal Corporation has recommended people avoid swimming in the river or eating fish from the river until more information was available.

Originally published as Dead fish in Mulgrave River at Cairns being investigated by authorities