Alarming photo shows unseen danger of Aussie flooding: 'Significant threat'

As parts of Victoria continue to battle this week's floods, with some northern towns still on high alert, there's another issue at hand causing a "significant threat", but not just to our homes.

An alarming photo shows the devastating impact floodwaters have on our oceans and marine life, with one expert calling flooding a "multi-dimensional issue" impacting more than just our towns.

Drone footage captured by Adam Stan Photography shows murky flood water hitting the sea at Barwon Heads, a coastal township on the Bellarine Peninsula, near Geelong, Victoria.

Cliff at Barwon Heads Victoria after floods
Photos taken at Barwon Heads, on Victoria's south coast shows the devastating effects floods have on oceans and marine life. Source: Reddit

While some 100km from the hard-hit suburb of Maribyrnong in Melbourne's north — where hundreds were forced to evacuate — the impact of the floods is noticeable along the south coast beaches too.

Images show the usually aqua water turning a shade of muddy brown as the floodwaters wash from rivers and towns and out into the sea.

Dr Agus Santoso from the UNSW Climate Change Research Centre told Yahoo News Australia "flooding is a multi-dimensional issue" and it's not just homes and communities destroyed, but our oceans too.

"It is not just confined to infrastructural damages, but also water pollution and its downstream effect on marine health in the ocean, among others," he said.

"Floods can transport sediments and urban pollutants, such as microplastics etc., to rivers and eventually to the sea. This poses risks to marine ecosystems and human health down the chain.

"Similarly, floods can also contaminate agricultural land."

Climate Council research director Martin Rice agrees saying, "stormwater runoff is a significant threat to aquatic ecosystems."

"As water runs over and through the watershed, it picks up and carries contaminants and soil. If untreated, these pollutants wash directly into waterways carried by runoff from rain and floods," he told Yahoo News Australia.

Generally speaking, Mr Rice said extreme wet weather conditions like we've seen this year can have a significant impact on the water quality and safety of our rivers and beaches.

Ocean Grove beach, Victoria after floods
A Melbourne resident visited the beach at Ocean Grove on the south coast and noticed the water was brown after the floods. Source: Imgur

Oceans unsafe for humans after floods

Not only is it harmful to marine life, but humans are also at risk.

"When flooding occurs, large amounts of debris are often found floating and submerged in all waterways," Mr Rice explained.

"Swimming in waters affected by stormwater can expose swimmers to a number of dangers, including pathogens which can make you sick, and hidden debris below the surface which you could collide with or become snagged under the water."

Locals have taken to social media in recent days to comment on the "sad" reality of floods.

"Been walking around the Yarra last few days, all the trees are full of plastic from where the flood waters met the treeline. So disgusting and sad," one said.

"Yeah I saw the same thing in Ocean Grove today, waves looked filthy, but still a few people in the water," said another.

SES workers are seen in Maribyrnong, Melbourne, after flooding
Maribyrnong in Melbourne experienced flooding on Friday following an onslaught of heavy rain. Source: AAP

Flooding attracts sharks, expert says

Lawrence Chlebeck, Marine Biologist from Humane Society International, previously told Yahoo News Australia another reason why people should avoid beaches amid heavy rain and flooding is an increase of sharks.

"Sharks are very intelligent animals and they've specialised in making the most of feeding opportunities," Mr Chlebeck explained.

"One of the things that sharks have learned to do is follow rivers after heavy rainfall because lots of different things will be washed into the ocean."

Dr Leonardo Guida, Shark Scientist at the Australian Marine Conservation Society, explained that a lot of nutrient runoffs from the land washes into the waterways and that attracts a lot of fish, which in turn attracts the sharks.

"The food chain goes into full gear and the bull sharks are taking advantage of what is essentially a feeding opportunity," he told Yahoo News Australia.

Sand bags are seen in flood water along a strip of businesses In Rochester, Victoria, Friday
Rochester in northern Victoria was also badly hit on Friday as more flooding is expected in the coming days. Source: AAP

More flooding expected in Victoria

Evacuation warnings are now in place for people in Echuca, near the Victoria border, as the Murray River is expected to peak Wednesday, Australian Associated Press (AAP) reported.

People in the northern Victorian town spent most of Monday building a makeshift sandbag levy in an effort to protect thousands of homes and businesses.

More than 1000 Echuca properties were already inundated with floodwaters on Sunday after the Campaspe River broke its banks.

There are also concerns the rural town of Kerang, about 95 kilometres northwest of Echuca, will become isolated due to floodwaters.

Major flooding at Kerang along the Loddon River is expected overnight on Tuesday and into Wednesday, with the water forecast to peak around the January 2011 peak soon after.

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