The long-awaited rains in Australia that have provided relief to the bush fires are having a deadly side effect by creating toxic water systems that have killed fish and put other wildlife at risk. Thousands of fish have been found in the Macleay River in New South Wales. This was a fear of researches who suspected this may happen. This is likely caused by the rain carrying charred debris into rivers through dams and into the ocean.
The recent rains have resulted in ash streams and rivers which have poisoned the fish. The Australian Department of Primary Industries, which has been receiving reports of “hundreds of thousands” of dead fish in the river since December 2019, tells us that ashes can effectively decrease the oxygen in the water, which would cause the death of many fish. Fish aren’t the only ones threatened — any type of freshwater wildlife, such as turtles, are threatened by this as well.
Area locals have told The Guardian that the rain in the past 10 days has seen more ash and mud from the devastated landscape running into the river. This disaster on the Macleay River is just one of eight fish massacres reported to the department this year. Recreational fisherman Larry Newberry told The Guardian that “I would say from what I’ve seen I would not be surprised that it’s wiped out every fish in at least 100 kilometers of the river.”
“I’ve been fishing the river for 50 years and I have seen fish kills before, but nothing of this magnitude. This will be happening in every east coast river that’s been hit by bushfires,” he adds. As these rains continue to help put out the fires, it seems that one disaster could be giving birth to a new one.
This toxic water may post a threat to humans as well. Water reserves of larger cities such as Melbourne are threatened by the increased amounts of algae in the rivers, which also contributes to the deoxygenation of the rivers. Not only that, but it makes these rivers iron and manganese soluble. If you’ve ever cut your lip and tasted your blood, that metallic taste is iron. That and manganese would make the water taste, smell, and look gross.
Another victim of these disasters is the small duck-billed platypus. Ross Thompson, a freshwater ecologist at the University of Canberra, told National Geographic that he was extremely concerned about the effects on freshwater ecosystems. These ecosystems provide a home to the platypus which has no way to dissipate heat and can’t stand hot water. The loss of vegetation due to the fires could increase the water temps and cause these poor creatures to return to their burrows to die a slow death.