As much needed rains fall in bushfire hit areas in Victoria and New South Wales, conservationists have warned about the dire consequences for our estuaries and coastal waters from run off choked with sediment and ash.
Australian Marine Conservation Society (AMCS) fisheries spokesperson Adrian Meder said essential fisheries and our important coastal habitats could be damaged by the run off, impacting many species, including commercially important seafood like prawns, snapper, whiting and flathead.
“We welcome this desperately needed rain but there’s a flip side with all the ash and sediment from the fires that will wash downstream. The recent run offs have already resulted in fish kill events in our rivers, and this choking water is now making its way down our clear, calm estuaries,” he said.
“Coastal estuaries are already under so much pressure. They’re critical habitats for a range of species found nowhere else, as well as many commercially important fish species.
“It could take years for estuaries in Australia to recover from such devastating impacts, and for Australians to enjoy their abundant waters again.”
Meder added that research had found that bushfires could increase nutrient input into streams 100-fold, so it was vital that authorities monitor these issues and quickly implement effective management plans.
Meder explained that the enormous bushfires had destroyed much of the natural filtration between land and ocean that forests provide.
“We can expect to see a massive and rapid increase in organic matter washed into our estuaries. This leads to deoxygenation, toxic algal blooms and ultimately fish kill events,” he said.
“We may also see invasive species capitalise on the altered nutrient balance and predate or graze on native species. The loss of this natural erosion barrier for coastal catchments burnt in the fires will mean sedimentation is likely to directly smother seagrass beds, alter estuarine water circulation resulting in muddy water, starving underwater plants of sunlight and impacting the food chain.
“Ultimately, we need the Australian government to take preventative action on global warming to try to prevent another disastrous bushfire season like we’re currently experiencing. Australians recognise that the only way to achieve this is to urgently lower emissions by switching from dirty coal and gas to clean renewable energy. Australia should be leading the way as a global renewable energy superpower, rather than a global fossil fuel pariah.”