Thousands of fish have been killed in rivers across NSW, likely due to the aftermath of ex-Tropical Cyclone Alfred, according to experts.
OzFish, a fish habitat charity, reports that fish in the Northern Rivers and Mid North Coast areas have been seen gasping for air or found dead.
The first reports of dead fish came from the Richmond River in Ballina, following severe flooding from the cyclone.
Similar reports have emerged from the Clarence River near the Queensland border and the Macleay River.
OzFish CEO Cassie Price attributes the fish kills to blackwater, a phenomenon caused by flooding that washes organic material into waterways, reducing oxygen levels as it decomposes.
This leads to suffocation of aquatic life, including flathead, bream, whiting, prawns, and other species.
Mud crabs and eels have also fled the water. Tests show oxygen levels in some areas are dangerously low, with the Richmond River recording just 0.4 mg per litre—well below the 5 mg per litre needed for healthy fish populations.
Price emphasizes that restoring swamplands along rivers could help mitigate such events, as healthy swamps filter out harmful blackwater.
Urgent action is needed to prevent further fish kills and improve the resilience of waterways. Locals are encouraged to report dead fish to OzFish.
Additionally, a new report highlights the growing burden on vulnerable coastal communities, with repeated natural disasters pushing up insurance and other costs.
