Don't get me wrong, I love fishing of all types, but going to this location to chum the water so you can spear a monster yellowfin seems lame. Personally catch and release would be a way more sustainable way of keeping that fishery at that level, can't really do that with a spear tho.
If you're gunna eat it i don't see the problem. That being said, after spearing 2 I'd probably start chumming the surface to see if I could catch any on the fly for some good ole catch and release.
Most tuna fishermen feed every friend and family member off a few decent fish. In the more remote locations the fish get shared around with locals who could only be very grateful. You only need to go to a fishmarket and see what blue or yellowfin tuna sells for fresh to know that it certainly wouldn't be allowed to go to waste.
Late to the party, but please remember, Spearfishing is still the most sustainable form of fishing with the least bycatch. The fact is, they're not gonna kill 100 fish a day or even 20 fish a day. This is an amalgamation of clips from probably a week long trip. And none of the food is wasted or for big corporations. They're usually eaten by the spearo, his family and friends and (with big fish like these) locals in the area as this fish can't be transported back to the spearo's homeland via plane.
