That’s how Sunday morning started out for Tony Lenthall … before he uttered some words – which will be left to the imagination – and called fishing partner Jason Didio for a hand.

While some may reconsider their fishing choices, for Tony, it was a dream come true.

“We’ve been fishing the river here for sharks for a couple of years now – about three – targeting sharks,” Tony said.

“But this big one has been two years in the making. I've researched and watched videos and seen what other blokes do up and down the coast and had ideas on how to do it … so it's taken two years to get to the point now where I've successfully landed it.”

He said the female shark put up a mighty fight, taking nearly half an hour to land and towing the boat around the river.

“It put up a monstrous fight and was really tough to pull in … they are just so powerful.”

The pair said they knew there were plenty of sharks in the river, ranging in size, but this was the “biggest one by a country mile” Tony has caught so far.

They estimate the shark weighed anywhere between 170 and 200 kilograms and by the size of its girth, could well have been pregnant.

“It was a big fat pregnant female that was coming in to give birth … that's what they do. It wasn't coming in to eat people's legs off or chase them up the river or anything,” Tony said. 

Jason added the females came in from the ocean and swim up the river to drop their pups.

“They can't lay their pups out sea because they'll eat them,” he said.

“And it’s certainly not uncommon, I’ve hooked heaps of them for tagging and research purposes so we put a tag in them and that's got a serial number on it.

“With the serial number you put down where you caught it - location and GPS markers of longitude and latitude - the length, how round the shark is, where hooked on the body, healthy release etc.”

Tony said the real fascination for himself and Jason was the science and learning more about sharks.

“Someone might catch that shark up in Cairns in six months time and we'll know it's travelled that far in that amount of time. From that, they can record some sort of science around where they go and what they do and hopefully we all learn more about their lifestyle,” Tony said.

“I've always been fascinated with sharks growing up. I was talking to a bloke from Department of Primary Industries who said there's really only a four to six week window of the big ones coming in to give birth.

“They suggested there's bull sharks in the river all year round, but that the bigger ones leave when it gets cooler and head north and the smaller ones stay in the river.

“For now, we’ll just keep tagging and releasing as we go.”