A teenage boy from drought-ravaged Tenterfield is so worried about the health of the fish in his farm's river he has taken matters into his own hands to save them — one at a time.

Stuart Moodie has managed to rescue more than 100 native fish on the Mole River, in far northern New South Wales, by catching the fish by hand in muddy water and moving them into larger waterholes.

"I've been going down early every day after school and catching the catfish and cod and taking them out and putting them in a dam, keeping them alive as much as I can," he said.

Stuart Moodie has caught and killed more than 300 carp over the past 12 months. ( ABC North Coast: Bronwyn Herbert )

The 13-year-old said a neighbour taught him how to hand-catch fish and he has since then refined his technique, relying on the sense of touch.

"I got used to getting in the waterhole nearly each day, got used to the fish feeling me and every time they touched me I push their head into the mud. It's just easiest to keep them calm and catch them," Stuart said.

He has had some memorable experiences.

"I caught a 123-centimetre carp and it just knocked me over. I just face-planted into the water," he said.

"Then with the catfish, every time I go grab them I just get spiked. And the cod, one grabbed hold of me and wouldn't let go and [I was] sitting there with the cod on my hand."

The Mole River, near Mingoola on the New South Wales-Queensland border, is in desperate need of more rain. ( ABC North Coast: Bronwyn Herbert )

Boy born to fish

His father, John Claydon, said his son had always loved fishing, right from when he could walk.

He had caught his 'proper' cod measuring 59 centimetres by the age of four.

"It's just something he likes and enjoys. He just can't see the sense in the fish dying when he can be down here catching them and moving them," Mr Claydon said.

"He's just got a bit of motivation and drive to do this thing. That's just what he loves. He's never watched television apart from National Geographic and the nature animal shows.

"Now the waterholes are absolutely buggered [the fish are] just dying in the waterholes they are so stagnant. We have a couple of dams he is holding them in."

Stuart's efforts have not only included saving native fish, but killing more than 300 carp — an invasive pest species.

The 13-year-old has caught and killed hundreds of carp, a pest species, from the Mole River. ( ABC North Coast: Bronwyn Herbert )

His work has caught the attention of the local community, including the Tenterfield Mayor Peter Petty.

"It is kids like Stuey the community is really proud of. He is mature beyond his years and he is really concerned about the situation down there because he lives there," Cr Petty said.

"I think he will be a role model in the future."

Scientists have been encouraged by the teenager's individual effort and by keeping fish in the same river system so as to help breeding stock recover once the rain returns.

But fisheries biologist Dr Daniel Boucher from Southern Cross University says people need to understand that fish living in these conditions are often sick.

"The fish you are moving have been living in very stressful conditions — low oxygen levels, crowded together. Their immune system becomes suppressed." Dr Boucher said.

Dr Daniel Boucher called for more funding to temporarily move stressed fish. ( Supplied )

"Ideally the best solution would be to be able to take those fish into a healthy environment where you can catch them again when the rainfall comes back and put them back in the system. So some off-site facility where you can treat them.

"You would prioritise what we call 'the BOFFS' — the big, old, fat, female fish — because they are your breeding stock."

Dr Boucher also called for more funding to temporarily move stressed fish before it was too late.

"What we really need is a plan, the right infrastructure, and we need the staff in fresh water systems to be able to get our ecosystems through these catastrophes," he said.

The New South Wales Government has relocated more than 1,600 fish from across the state since September as part of its $10 million fish rescue strategy.

Stuart Moodie with his dog, Mel. ( ABC North Coast: Bronwyn Herbert )

For Stuart, he just hopes the drought breaks soon so he can get back to what he loves best.

"I'm praying a lot really so I can let them go, and the river flows again, and I can go fishing really."