Most used size tuna hook?

How to Catch Yellowfin Tuna - Tips for Fishing for Yellowfin Tuna

Tuna Fishing: all you need to know about this legendary fish - Tom's Catch Blog

Mid-range Trolling: Perfecting the Spread - The Fisherman

Bridling Live Tuna for Billfish

The Most Complete Guide to Tuna Fishing

How to Catch Longtail Tuna on Lures – Tackle Tactics

Choose the Right Hook for the Job – Salmon University

If You Eat Tuna, You Should Know These Five Fish - Greenpeace USA

Bluefin tuna hooks

CA Marine Species Portal

Bluefin Tuna on The Fly: An Attainable Pipe Dream - Flylords Mag