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. 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. 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. 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.