Hawaii's pelagic fisheries

Marine Fisheries Review, Spring, 1993 by Christofer H. Boggs, Rusell Y. Ito

All handline catches were sold on the Island of Hawaii where the fishery was primarily located until 1971 when the rising price for tuna and reduced shipping costs made air shipment to Honolulu economically feasible. The increasing market for fresh fish boosted the development of Hawaii's fisheries in the mid-1970's (Pooley, 1993a). Annual commercial handline landings reported to HDAR increased from 45 t to almost 1,000 t between 1970 and 198 1. Since 1981 commercial handline landings have ranged between 500 and 1,000 t (1.1-2.2 million pounds) with major peaks in 1981, 1983, 1986, and 1991 (Fig. 3). The magnitude of the recreational-subsistence sector of the handline fishery is unquantified, but important (Pooley, 1993a).

The composition of the handline catch is almost exclusively tuna; yellowfin tuna is the predominant species (Fig.. 3). Mahimahi and other nontuna species make up less than 10% of the catch. Bigeye tuna are an important component of the handline catch (Yuen, 1979) that is not reflected in HDAR statistics. The ika-shibi catch of bigeye tuna ranged from 63 to 120 t (139-265 thousand lb) in 1973-75 (Yuen, 1979), but HDAR records indicate <23 t of tuna other than yellowfin landed by all handline fishing gears in 1973-75 (Fig. 3). This may represent a lack of reporting, but it is also likely that handline fishermen are lumping both bigeye and yellowfin catches as ahi in their catch reports since these species have the same Hawaiian name.

Most handline vessels are 6-9 m in length and are often crewed by 1-2 persons. Surveys by Yuen (1979) and Ikehara(15) indicate that the ika-shibi fishery grew from 30-40 boats in 1976 to at least 230 boats by 1980. In recent years some of the smaller longline vessels and larger commercial troll vessels have also done some handline fishing.

Day-handline fishing was concentrated around the Island of Hawaii and ika-shibi fishing was concentrated off the Hilo coast of Hawaii in the mids. 1980's. Traditionally, handline fishing was conducted within a few km of the coast at locations called "ahi koas" where yellowfin and bigeye tuna were especially available. The State (HDAR) encouraged expansion into new areas in the late 1980's. Handline fishing techniques have spread and are now practiced on Kauai and Maui. Some of the largest handline vessels have extended their range to fish around seamounts and weather buoys 100-200 n.mi. from the coast. This new expansion of the fishery may have contributed substantially to the peak in catch reported in 199 1, which followed four years of continuous decline (1987-90, Fig. 3). Some fishermen feel that there may soon be too many participants in the handline fishery, and the WPRFMC has been asked to institute a control date for this fishery in anticipation of possible limited-entry management.

The increasing cost of insurance has been a problem for small-vessel commercial fishermen. Many operators could not afford to keep up with rising insurance costs in the late 1980's and some, who weren't willing to risk their assets, stopped fishing. Another economic problem for the commercial troll and handline fisheries is a condition called burnt tuna syndrome (BTS) which discolors and gives a bad taste to sashimi as well as reduces its shelf life (Nakamura et al., 1987). BTS is prevalent in troll and handline-caught fish over 35 kg and uncommon in longline-caught fish. Proper handling can ameliorate BTS (Nakamura et al., 1987) and research is under way to find means to prevent it (Watson et al., 1988).