Availability & Seasonality
The supply of locally-caught mahimahi is extremely limited and seasonal considering the high demand for this species. Although available most of the year, mahimahi catches usually peak in March-May and September-November. Most of the fish are between 8 and 25 pounds, but larger fish are caught by trollers and smaller fish by the pole-and-line skipjack tuna fleet.
Product Forms & Yields
Local fishermen market their mahimahi as fresh, whole fish. Most are purchased by up-scale restaurants in Hawaii and on the mainland. Some restaurants buy fillets from intermediary suppliers, but others prefer to receive the fish whole or grilled and gutted to retain good quality. Mahimahi over 15 pounds in body weight is the preferred market size. The average yield of fillet from whole fish ranges from 40-45%. A better yield can be recovered from large fish and from females than from small fish or males (which have bigger heads).
Shelf Life & Quality Control
Fresh mahimahi has a shelf life of 10 days if properly cared for (see Table 3). The fish caught by trolling (or incidentally by the pole-and-line aku boats) are only one or two days old and, hence, are typically fresher than the mahimahi caught by longline boats on extended trips. The first external evidence of deterioration in a whole mahimahi is softening and fading of bright skin colors. In a dressed fish, discoloration of the flesh exposed around the collar bone would indicate a loss of quality. Mahimahi retains better quality if it is not filleted until shortly before use. Imported mahimahi fillets of low quality may have high levels of histamines. Naturally-occurring spoilage bacteria probably act on the plentiful amount of histamine in mahimahi to produce biologically active histamines. When ingested in sufficient quantities, histamines give rise to an allergic-type reaction. Histamine problems can be avoided by properly chilling pelagic species from the time of capture to processing and consumption.
