Toxic Water ‘Unlikely’ To Be Cause Of Lake Macquarie Fish Kill

Toxic discharge has been all but ruled out as the cause of a fish kill at Lake Macquarie by the NSW Environment Protection Authority.

Hundreds of fish were found dead at Mannering Park on August 5 prompting a full investigation.

Test results have now come back with the EPA confirming the water is not acutely toxic, making it unlikely to be behind the deaths.

The process involved testing for a full suite of metals and found levels below the ANZECC marine water quality guidelines. Preliminary water results for pesticides were also measured at below the laboratory limit, while levels of pH and electrical conductivity are within normal ranges for a saline lake.

Samples do, however, show signs of sediment disruption with Total Nitrogen and Total Phosphorus above guideline values.

According to the EPA, these results indicate the most likely cause of the fish kill was a natural event.

This would line up with reports from EPA Officers who first attended the site and observed dead fish of various species and sizes with greying around the gills, suggesting possible oxygen depletion.

Investigations will continue though as the EPA awaits pesticide results as well as the analysis from the fish that were collected on August 5.

These are expected to be available next week when they will also be released to the public.

More information can be found on the EPA website.