I. Biological Description
Tombo ahi (Thunnus alalunga) is commonly known as albacore tuna. Other names for this species include Pacific albacore, tombo, and “white meat” tuna. The tombo ahi caught in the vicinity of the Hawaiian Islands are large (over 40 pounds in round weight) adult fish. Smaller, immature tombo migrate extensively throughout the North Pacific far north of the Hawaiian Islands.
II. Of Special Interest For Buying/Distributing
Availability And Seasonality: Commercial landings of tombo ahi have increased in Hawaii. Tombo ahi is seasonally available in significant quantities, but is scarce in the off-season. The peak in landings usually occurs from May through September. There are also wide fluctuations in the annual catch of tombo ahi. Availability is greatly influenced by oceanographic conditions. Tombo ahi is believed to migrate along ocean temperature “edges” rich in food, hence, disruption of ocean-wide current systems, such as brought about by “El Nino” weather, may affect catch rates in Hawaii.
Fishing Methods: Most of the tombo ahi catch in Hawaii is landed by commercial longline boats which set hooks at the swimming depths of the large tombo (75-150 fathoms). A small portion of the catch is made by the small-boat handline (ika-shibi) fishery based on the island of Hawaii.
Distribution: The longline catch and much of the handline (ika-shibi) catch of tombo ahi is marketed through the Honolulu fish auction. The remainder of the handline catch is sold through the fish auction in Hilo and through intermediary buyers on that island. Most of the albacore caught in Hawaiian waters consist of mature fish, 40 to 80 pounds in round weight. Most of this fish is sold fresh, but surpluses caught during the peak summer season are sometimes smoked.
Substitution: Despite having a pinkish rather than reddish flesh, tombo ahi occasionally substitutes for other species of ahi or for aku in raw fish preparations. It is completely interchangeable with other ahi or a‘u species in broiled or sauted forms, although it may be more susceptible to overcooking than the other species. Tombo is also interchangeable with other tuna and marlin (a‘u) for dried and smoked products.
III. Of Special Interest For Preparation/Quality Control
Shelf Life And Quality Control: Some longline boats which catch tombo ahi are at sea for up to 10-12 days, but with proper care, the fish will retain a high quality for three weeks after capture (see Table 3). Although not as old when landed, the quality of handline-caught tombo is more variable because of differences in handling by the small-boat tuna fleet.
Product Forms And Yields: The preferred market size of tombo ahi for use in fresh or processed products is greater than 50 pounds in the round. The larger fishes have several advantages: (1) greater yield of finished product — 60-65%, (see Table 5); (2) pinker flesh coloration; and, (3) greater fat content than smaller tombo. Fresh albacore is also marketed as loins, loin sections, or steaks at fish markets or supermarkets with fish counter service or self-service counters. Tombo is one of the preferred species for gourmet smoked fish products.
IV. Of Special Interest To Consumers/Food Service Personnel
Color, Taste, Texture: Tombo ahi has flesh that varies from whitish-pink in smaller fish to deep pink in larger fish. Larger tombo ahi have a greater fat content than smaller fish, and this is a desirable attribute for raw fish products, as well as for broiling.As raw fish, tombo is softer than other ahi or aku and, hence, more difficult to slice into sashimi. The flesh becomes much firmer when cooked than when in the raw state.
Preparations: Restaurants usually grill tombo ahi, but other cooking methods will work as well. Tombo has a tendency to dry out quickly, so it is important to avoid overcooking.
V. Historical Note
Albacore is the only tuna species which can be canned as “white meat” in the U.S. The west coast albacore fishery began in the early 20th century as canning techniques were perfected. However, it was twenty years before albacore became recognized as a premium canned product. With recent cannery closures on the U.S. west coast and wide fluctuations in cannery prices for tombo ahi, an increasing quantity is entering the fresh and fresh frozen restaurant market.