The following portions of the Introduction provide summary information useful in buying and prepar-
ing Hawaii’s major fish species. The approximate shelf life of these species from the time of capture
is estimated in Table 3.
It should be remembered that variations in handling and in ocean and weather conditions will cause
individual fish to vary in shelf life from the generalized estimates. Table 4 reviews the most readily
available product forms for the major fish species. Table 5 summarizes the typical landed size of
these species and the approximate yield (as percentage of round weight of the most readily avail-
able product forms). Table 6 provides general advice on appropriate quantities of fish to buy depend-
ing on intended use.
Most of Hawaii’s fish products may be used in a variety of ways. Table 7 indicates the most common
methods of preparation for the major products included in the Guide. Table 8 provides nutritional and
dietary information about selected species.
Four species of tuna are landed in substantial quantities in Hawaii:
• Albacore tuna (Thunnus alalunga) or tombo ahi;
• Bigeye tuna (Thunnus obesus) or ahi;
• Skipjack tuna (Katsuwonus pelamis) or aku; and,
• Yellowfin tuna (Thunnus albacares) or ahi.
Tuna caught off the Hawaiian Islands belong to stocks which migrate long distances across the
Pacific Ocean, and their availability in Hawaiian waters is seasonal. In Hawaii, the peak season for
most tuna species is summer (April-September), but in contrast, the heaviest landings of bigeye tuna
occur in winter (October-March).
The major quality factors over which fishermen have control include: freshness (which varies with
length of fishing trips and initial handling of the catch); initial handling (rough handling, dragging,
bending or dropping will ruin the general appearance of the fish, as well as cause the flesh to lose its
firm consistency or to crack); and, time the fish is left in the water after capture (too long a time will
bleach out the original bright body colors and cause a loss of flesh color).
The initial quality of the tuna when hooked is not under the control of the fisherman. Many natural
factors influence initial quality. One of the most important is spawning. Prior to the spawning, tunas
(and most other fish species) feed voraciously and increase their body fat content substantially. After
spawning, their fat content is very low and the water content of the muscle is high, rendering the
quality of the fish inferior. Shelf life is relatively lower, even under ideal storage conditions, in tuna
and other fishes having red muscle tissue. Pigmented muscle is rich in iron and copper, two minerals
that promote oxidative rancidity. Removal of blood with its iron containing pigments that foster
oxidation will extend the keeping time of fresh tuna. Therefore, if tunas are landed while still alive,
they should be bled. After bleeding, they should be submerged in an ice-seater brine to bring down
the core temperature of the fish. After the core temperature is reduced or if the fish is landed dead
(as is often the case in longlining), the catch should be individually packed on ice. As with all seafood
products, conscientious handling and proper icing of tuna are prerequisites for a high quality product.