Hawaii’s surrounding waters are a vibrant habitat for several tuna species, which hold significant cultural and economic value for the islands. Tuna, known locally as “ahi” for some species, are not only a staple in Hawaiian cuisine but also support a considerable fishing industry. The abundance of these powerful pelagic fish in the region contributes to both the local diet and the broader marine ecosystem.
Yellowfin Tuna (Ahi)
Yellowfin tuna, or Thunnus albacares, is known as Ahi in Hawaii. This species has a streamlined body and distinctive bright yellow dorsal and anal fins, which can lengthen significantly with age. Smaller yellowfin tuna are sometimes referred to as “shibi” in Hawaii. These fish can range to over 200 pounds, with larger specimens typically found in deeper open ocean waters.
Yellowfin tuna thrive in warm, clear tropical and subtropical oceans, and are abundant in Hawaiian waters year-round, with peak availability from May to September. They often school with other tuna species, including skipjack, and sometimes associate with marine mammals or drifting objects. Yellowfin tuna flesh ranges from pink to deep red, and its firm texture and mild flavor make it popular for various culinary preparations, including sashimi, grilling, searing, and poke.
Bigeye Tuna (Ahi)
Bigeye tuna, Thunnus obesus, also shares the Hawaiian name Ahi, often causing confusion with yellowfin. Bigeye have a more robust, plump body, larger head, and noticeably larger eyes. Unlike yellowfin, bigeye tuna typically have darker, more reddish flesh. Bigeye tuna usually range from 20 to over 200 pounds in Hawaii.
Bigeye tuna inhabit deeper, cooler waters compared to yellowfin, typically spending their days around 200 to 400 meters (650 to 1300 feet) where temperatures are between 10-17°C, and ascending to shallower, warmer waters at night. This species is valued for its higher fat content and richer flavor, making it a preferred choice for sashimi and sushi. Bigeye tuna is a significant catch for Hawaii’s longline fleet, with peak landings in the winter season from October to April.
Skipjack Tuna (Aku)
Skipjack tuna, Katsuwonus pelamis, is known as Aku in Hawaii. This species has a torpedo-shaped body and prominent dark stripes on its silvery belly. Skipjack are generally smaller than Ahi species, commonly weighing between 4 and 15 pounds, though larger fish up to 30 pounds can be found in Hawaiian waters during summer.
Skipjack tuna are schooling fish, often found near the surface and sometimes under drifting objects or marine mammals. In Hawaii, skipjack tuna is frequently used for poke and dried fish products like katsuobushi due to its stronger, oilier flavor. Historically, Aku was the most important commercial fish species in Hawaii by landed weight and value.
Albacore Tuna (Tombo)
Albacore tuna, Thunnus alalunga, is called Tombo in Hawaii, a name derived from the Japanese word for dragonfly, referencing its exceptionally long pectoral fins. These fins can extend to as much as 30% of the fish’s body length. Albacore have a metallic dark blue back and silvery-white undersides. Fish caught near Hawaii are typically large adults, weighing 40 to 80 pounds.
Albacore tuna are widely distributed in temperate, subtropical, and tropical waters, often found in cooler, deeper oceanic environments. It is known as “white meat” tuna due to its lighter flesh color when cooked, and its mild flavor makes it popular for canning. While it can be eaten raw, its softer texture makes it less ideal for sashimi compared to other tuna species. Albacore is mostly sold fresh in Hawaii, with peak harvests occurring from April through October.