Alstonville man Steve Posselt has completed his marathon paddle from Brisbane to Sydney to protest against plans to dam the Mary River in south-east Queensland.

In Sydney today Mr Posselt handed over more than 3000 letters of protest to Federal Minister for the Environment, Peter Garrett.

The 55-year-old civil engineer’s epic journey ended at the Opera House. It was his second major journey — last year he paddled from Brisbane to Adelaide along the Murray-Darling river system to highlight the dire straits of our inland waterways.

On hand to greet him in Sydney today were conservationists, supporters and media.

Mr Posselt, who has worked in the water industry for 37 years, says the Queensland Government’s plan to dam Traveston Crossing on the Mary River will threaten the existence of the ancient lungfish, which pre-dates dinosaurs.

He said in Sydney today: “We are treating our rivers as drains and they are responding as drains.

“If we don’t fix this, we are threatening our very existence.”

Mr Posselt averaged more than 40km a day on his journey.

If the seas became too rough, he walked his kayak along roads and beaches to his next destination, as evidenced when he walked from Byron Bay to Ballina along the coastal road, and then from Ballina to Wardell when the Richmond River bar was too rough to cross.

On his website, Mr Posselt reflected on his long journey.

“The low point had to be tipping over off Burleigh Heads,” he wrote.

“It was probably good that it was a few kilometres out to sea so I did not get caught in the surf or the rocks.

“It felt very isolated though, as there was no other silly bugger out in that stuff.

“Shark sightings made for an adrenalin rush and some concern, but for sheer exhilaration, the close encounter with the whale tops the list.

“Paddling along quite peacefully there was a very loud noise just behind my left shoulder: ‘Thrrrrwhooooofff’. ‘Phaark!’ I yelled instinctively as I turned my head.

“There was a whale less than two paddle lengths away.

“People have asked, ‘Was it a humpback?’. Who knows? Who cares? It was grey with white bits, and barnacles, and it had given me the fright of my life.

“It took a very long time before my heart stopped racing and the image is etched in my brain forever.

“You just can’t get this sort of experience unless you are out there and are vulnerable.”

Mr Posselt said he intended to return to home on Sunday — by road.

“Would I do it again? I doubt it, but it was certainly worth doing once,” he said.