Inspectors from NSW Fisheries and NSW Environmental Pollution Agency acting on community concerns were on the ground yesterday (Tuesday 8 July) at Lake Cargelligo and Lake Curlew to investigate mass deaths of native fish.

It follows a large fish kills at both inland lakes over the past couple of weeks.

Aquatic ecologist Dr Adam Kerezsy says the native bony herring fish are dead in big numbers, probably thousands.

‘’There are large numbers near the banks and few of us including fish biologists have put our heads together," Dr Kerezsy said.

"We’re pretty sure it’s a combination of a cold snap and the Lake got drawn down to fifty per cent last year and summer was hot and in May it was super-hot but we are leaving some of our suspicions open.’’

Dr Kerezsy lives near Lake Cargelligo and hopes investigators could uncover something new.

‘’The response from Fisheries and the EPA has been rapid so we can’t fault them,’’ he said.

‘’The bony herring has lived on this continent for centuries and this winter has been colder so it could be something much different.’’ 

Dead bony herring at Lake Cargelligo. [IMAGE: Adam Kerezsy]

Dr Kerezsy started seeing small numbers of dead fish about two weeks ago and alerted agencies.

‘’Birds are doing well out of it at the moment but I imagine summer could be different and its only affecting fish between 10 to 20cm."

The Department of Primary Industries said together with Water NSW investigations would continue.

State MP for Barwon in Lake Cargelligo said he was working with community and authorities to determine the cause but it is possible that there is little that could have been done to prevent the fish deaths.