Mystery after piles of dead fish found on Sydney river

There’s a mystery surrounding the deaths of fish in southwest Sydney.

Sydney Harbour Recreational Fishing Haven posted video to Facebook on Tuesday about the dead fish found washed up on Liverpool Weir.

“Endless dead fish,” the man says.

“What the hell?”

The man points out catfish, mullet and others with some about a metre long.

“Who knows what’s in this river or what’s getting put in it but it’s pretty sad to see,” he says.

It hasn’t been determined exactly what killed the fish but a number of theories have been floated on Facebook.

Fish found dead at Liverpool Weir. Source: Facebook/ Sydney Harbour Recreational Fishing Haven

Most people on Facebook believe ash from the recent bushfires may have caused the fish to die.

“Ash can be quite abrasive on fish gills,” one man wrote. 

“Interesting to see carp, bass and catfish all in there, three quite different species so it’s something that screws everything - some sort of pollution and not, for example, a virus,” he wrote. 

“If it is ash then, sorry to say, it’s ultimately climate change. Expect more of it more frequently.”

It’s a theory which carries weight too. Recent rainfall caused hundreds of thousands of fish to die in the Macleay River, on the NSW Mid North Coast, last week after ash from the fires washed into waterways.

Bellbrook resident Arthur Bain called the Macleay River fish deaths “devastating”.

One man suggested a far more sinister theory though.

“It’s not from the rain, no one ever sees fish die because of the rain, like come on - someone is poisoning the river,” one man wrote. “Simple.”

The Department of Primary Industries has been contacted for comment.

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