More than 100,000 native bony bream fish have died at Lake Menindee in western New South Wales. This mass die-off comes after a recent heatwave, marking the most significant fish kill in the lake since 2023.
Luke Driscoll, CEO of the Barkandji Native Title Group, reported that the dead fish washed ashore, particularly in Sunset Strip. He anticipates that many more fish sank and are not visible. The odor from the decaying fish is overwhelming for local residents, even from kilometers away.
Lake Menindee is part of a series of lakes near Broken Hill. This area has seen large fish die-offs in the past, notably in 2019 and 2023, where tens of millions of fish died due to low water levels and rising temperatures.
During the recent heatwave, Barkandji rangers discovered around 400 to 500 dead fish in the Darling-Baaka River, primarily consisting of carp. Just when the situation seemed stable, a sudden storm dropped temperatures, leading to the dramatic increase in fish deaths.
Prof. Fran Sheldon, an expert in environmental sciences, explained that fish like the bony bream struggle with sudden temperature shifts. The core issue, however, is oxygen depletion in the water. Fish become stressed in hot, shallow water, leading to mass die-offs.
Sheldon noted that the previous few years have seen positive water flows, allowing fish populations to grow. However, as the river dries up, fish become concentrated in smaller areas, increasing competition for oxygen and space. This trend has been exacerbated by a red alert for blue-green algae in January, which further compromised the fish’s environment.
The Australian environment faces ongoing challenges. In 2025, over four million salmon died in fish farms in Tasmania due to similar heat stress. Mass die-offs, while less common in the ocean, still occur; tens of thousands of fish washed up on the Pilbara coast in Western Australia after a marine heatwave. These trends highlight the broader impact of climate change on aquatic life.
Driscoll emphasized the urgent need for clean-up efforts and water quality testing following the incident. The Barkandji people, deeply connected to these waters, are saddened to witness the loss of a species that holds cultural significance.
As Australia navigates these environmental challenges, it’s clear that the health of its waterways is at a critical point. For more in-depth analysis, you can refer to reports from the Australian Bureau of Meteorology.
