http://www.bbc.co.uk/news/world-us-canada-34056313
I'm more than a little bit dubious about this claim, but at least let's take him at face-value at the first:-
Koen Norton, 10, was on his family's charter boat last Sunday, 23 August in the waters in Naufrage Harbour, off the coast of Prince Edward Island, Canada. He then hooked and, across an hour, using a fishing technique called "stand up" (involving a harness), fought & landed a gigantic 486lb (220kg) Tuna fish.