Wildlife rescue volunteers working along the Murray River have raised concerns that kangaroos could be dying after drinking contaminated flood water.
The alarm was raised after one-fifth of a population of kangaroos that have been trapped for three weeks on an island near Moama, on the New South Wales side of the border, died despite being an apparently healthy weight.
It comes as the Environmental Protection Authority (EPA) has released monitoring data showing levels of E coli and other contaminates in flood waters are above normal levels, but generally below levels of concern.
Rushworth ecologist Tania Begg, a longtime volunteer with Wildlife Victoria, was part of a rescue team who were sent to examine the trapped kangaroos after Wildlife Victoria received calls from worried locals. Of the mob of 100, about 20 died.
“We could clearly see animals that were very underweight but then there were animals there that looked otherwise healthy,” Begg said. “They were deceased but they hadn’t lost condition and they had passed away.”
There were no signs of starvation or predation, she said. Although the bodies of the animals were not taken for an autopsy, Begg said it appeared likely the cause of death was linked to the contaminated flood waters.
Water quality testing analysis by EPA Victoria found traces of E coli across regional testing locations earlier this month, with readings from the Goulburn River at Shepparton showing four times the amount of pathogens allowed under guidelines.
It follows reports of flooded rivers smelling like sewage and “unusual” fish deaths in the Murray River and surrounding waterways.
Macropods are particularly susceptible to E coli and salmonella, and to a parasite called coccidia which is found in the soil.
“Kangaroos are susceptible to this at the best of times” Begg said. “But once you’ve added a stress event like this … that’s going to have a further impact on these kangaroo populations as well.”
“For the animals it just keeps getting worse because they’ve run out of food and the water isn’t dropping fast enough for them to have access to more food,” Begg said.
Begg said there was a knowledge gap around the impact of prolonged flooding on wildlife in Australia.
“There’s a lot of bushfire ecologists in Australia, and I understand that, but I think right now we need a lot of freshwater ecologists to study everything right now, so that we can make sure that it doesn’t happen again,” she said.
Victoria’s chief environmental scientist, Prof Mark Taylor, said the EPA advised against people entering or drinking the water, or allowing livestock to drink it.
“Don’t go into water, just assume it’s contaminated … It’s not drinking water.”
E coli is a bacteria which lives in the intestines of warm-blooded animals and is found in both human and animal faeces.
“So you don’t want to be ingesting that, this is akin to ingesting a turd,” Taylor said. “The typical outcome of exposure to E coli is gastroenteritis and diarrhoea.”
The EPA has also received reports of people getting infected cuts after entering flood waters. “If you’ve had to go in that water and interact with it … always use soap and water and wash it really thoroughly,” he said.
Taylor said the greatest risk was for properties along the river, where the flood waters had settled over properties and become difficult to avoid.
“The risk is greatest where animals or livestock are operating because that’s their only source of food or water, they’re ingesting a low but an elevated amount E coli, which would then present potentially a risk of illness to those animals,” he said.
“Although [animals] are more resilient than people, they are not immune to it and we’ve seen lots of the animals that have been harmed either by standing in flood waters, or by having to try and migrate [through the flood waters].”
Taylor said E coli levels in the flooded river systems “will vary from place to place”, but added that on the whole, monitoring showed that most areas “do not present a very significant risk”.
He added that the water samples were collected at a point in time at a location and the E coli readings “could have been worse before and it could be worse again”.
“The E coli are representative pathogens and it gives an indication if that water has been contaminated by sewage overflows because that’s the most likely source, or from your agricultural sources,” he said.