Another of Netana's brothers almost fainted as the rod was pulled out of his foot in hospital.
Aupouri-Akuhata, a commercial kina diver who featured in TVNZ's series Spiky Gold Hunters, wants to share dangers of discarded crayfish pots.
He arrived at the Pouawa camp only to hear his little brother had been taken away in an ambulance, but later saw the damage in a gory picture.
"When I saw the photos, I was like 'you're kidding me, that's right through his foot'."
Netana has been in hospital since last Sunday.
"They won't release him until they know that tetanus isn't going to set in," Aupouri-Akuhata said.
His little brother can't feel his foot and can't walk, he said. The hospital is taking is recovery on a daily basis.
"This is what happens if you do leave your stuff in the ocean.
"I'm all for people gathering kai or seafood in any ways or manner they can, but at least take a little bit of time out of your day. If you do lose something, try your best to get it back.
Aupouri-Akuhata said the children had found other dangerous rubbish on the beach this summer, such as discarded hooks in the seaweed.
"They could've gotten a hook through the finger."
People need to be more aware of the harm discarded equipment can have, he said.
"If they don't know that it's causing harm, a lot of the time you would think, 'oh, it's lost in the sea, it'll never harm anyone'. But actually, it does."