The Hawaiian name “‘ahi” is used for all species of large tunas and has the meaning of “fire.” This refers to the fiery run the fish would make as it quickly pulled the line out of the ipu (bottle gourd) and across the side of the wa’a (canoe), quickly heating both from the friction.

Ahi fishing requires great skill and knowledge of the deep sea. The early Hawaiian fishermen regarded the ahi as a great fighter and formidable foe, and the ali’i (chiefs) often went sportfishing for ahi. Every island had its deep-sea grounds for ahi and were often kept secret.

National Marine Fisheries Service experts found that yellowfin tuna have sharper eyesight than the bonito or skipjack tuna under normal daylight conditions. This phenomenon has evolved as compensation for the greater swimming speed of the yellowfin, at roughly 10 miles per hour, the largest and fastest of the tropical surface water tuna.

A fish cannot hunt at top speed if it does not have the eyesight necessary to spot its quarry at long range. Without superior visual acuity, the racing tuna would be past its food before it even knew it was there. This sharp eyesight may also account for the early Hawaiians’ careful selection of lures for different light conditions.

Even with remarkable eyesight, the yellowfin often relies on an underwater mammal to find its food. Yellowfin frequently travel and feed with porpoises because they both feed on squid, skipjack and small fish. The porpoise does not need eyes to find its supper. Their sonar system is so well-developed that they can differentiate in the dark between two different types of food fish of exactly the same size without even seeing them.

What do tuna eat around Hawaii? The easy answer is they eat baby tuna, but their diet is far more diverse than that. A lot of what they eat doesn’t consist of fish at all. Squid of every size, shape and description end up in tunas’ stomachs. This is not surprising considering that there are scores of different squid species in local waters, and some of them are highly abundant.

A major portion of the diet of tuna also consists of “bugs” — various types of crab, lobster or shrimplike animals. The open ocean, or pelagic stage, of reef crabs and mantis shrimp are very commonly eaten by tuna.

Moving into the fish category, flying fish, juvenile aku and ahi and even baby marlin or spearfish are found inside their stomachs. The ocean triggerfish, drift fish, juvenile bigeye trevally, basselet and opelu that hang around local FADs also turn up with regularity.

What should be very interesting to local fishermen is the fact that during the summer and fall months, a major food source of tuna are the larvae or young of common reef fish.

While reef fish species spawn on the reefs or outer reef slopes, their eggs and larvae drift in the open ocean, sometimes hundreds of miles from the nearest reef or island.

So, there you have it. Local tuna usually eat (1) squid, (2) “bugs,” (3) flying fish and opelu, (4) baby tuna and billfish, (5) small fish, and (6) larval and prejuvenile reef fish.