South Australian ecologist finds fish kill along Coorong South Lagoon: ‘Not seen since millennium drought’

A South Australian An environmentalist says a dead fish she found over the weekend stretches more than 20 kilometers from the state’s coastline.

Faith Coleman, who has been working on the Coorong for the past six years, saw thousands of fish carcasses in the South Lagoon over the weekend.

She said this is the second fish kill in this area in 2024, following a similar fish kill in March.

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A similar event in the South Lagoon hasn’t happened at this time of year since the late-millennium drought, she said.

“There’s this band of dead fish that runs along the shore and covers the entire length,” Coleman said.

“It shines because it has all these birds on it that have come to eat the dead fish.

“You can actually smell it from the highway now, which is pretty disgusting.”

The Department of Primary Industries and Regional Affairs (PIRSA) said before being contacted by 7NEWS it was not aware of a fish kill in the Southern Lagoon.

He said fish kills can be caused by a number of reasons, “including environmental factors such as temperature, rainfall (or lack of) and water quality, including salinity or oxygen levels, or by disease or pollutants.”

Coleman said it’s possible a storm in the area stirred up sediment underwater, causing oxygen levels to deplete.

She said it could also be due to high salinity as a result of less water flowing into the Coorong from upstream.

“It’s progressing every year, every few decades, further north. There are areas of the North Lagoon that are quite sick and we occasionally get fish kills in the summer,” Coleman said.

“Over time they will deteriorate and we will lose almost everything in the Coorong.”

Coleman said the area where the fish kill occurred was between two monitoring systems and called for the department to set up the technology in more parts of the Coorong.

She said salinity levels in the South Lagoon needed to be better managed and water composition improved.

“I think it’s extremely important that we put the necessary monitoring in place so that we can detect these murders when they happen,” she said.

“I think it’s important that we have a field research center on the Coorong so we can make sure we can do the tests to make sure it’s not a disease.”

PIRSA encouraged members of the public to report fish kills to FISHWATCH on 1800 065 522.