I. Biological Description
Swordfish (Xiphias gladius), also known as broadbill, broadbill swordfish or shutome in Hawaii, are the most widely distributed of all billfish in the Pacific Ocean. Swordfish are caught in association with frontal zones where ocean currents or water masses meet to create turbulence and sharp gradients of temperature and salinity. Swordfish make vertical migrations through the water column, rising near to the surface at night from deep waters. Swordfish caught around the Hawaiian Islands are from stocks which migrate throughout the North Pacific.
II. Of Special Interest For Buying/Distributing
Availability And Seasonality: Exploratory fishing in 1989 demonstrated the existence of commercial concentrations of swordfish within the range of Hawaii's longline fleet. Concentrations of large swordfish around the Hawaiian Islands north of Oahu produce catches from April through July. Commercial catches are possible for several months preceding this period, usually at farther distances north of the Hawaiian Archipelago. Swordfish availability in this region may be related to the migration patterns of squid, known to be a major component of the swordfish diet. While searching for concentrations of swordfish, longliners often set gear along temperature gradients ("breaks") indicative of intersecting water masses.
Distribution: All of Hawaii's swordfish are landed and marketed fresh. Much of the catch is exported to the U.S. east coast, where domestic-quality swordfish can bring a premium price. Hawaii can already claim a major share of the U.S. market for domestic swordfish. Hawaii swordfish is superior in quality and is preferred over foreign imports by customers who have high standards.
Much of the landings are sold at the Honolulu fish auction, where most primary processors acquire their fish for export. Alternatively, some boats market and export their catch directly from dockside.
Most east coast buyers order entire airline containers (LD-#) of swordfish (2,500-3,000 pounds per shipment). The containers are well-insulated, and bagged swordfish are arranged carefully in layers with larger fish on the bottom and smaller fish on th e top. Swordfish shipped in this manner can be sent only to cities which are served by widebody aircraft capable of carrying containerized cargo.
Substitution: Consumers intent on purchasing swordfish are not likely to be satisfied by substitute species. Unscrupulous fish dealers may attempt to substitute mako shark, whose flesh bears a slight resemblance to that of swordfish, but this is fraudulent.
Blue marlin (kajiki) and striped marlin (nairagi) are sometimes incorrectly retailed in Hawaii supermarkets under the name "Hawaiian swordfish." Swordfish and marlin have the same general biological attributes and habitats, but they are not alike as seafood. Marlin has a more fibrous flesh than swordfish and tends to become firm and dry if overcooked. Swordfish tends to have a higher oil content, a richer flavor and has a texture similar to that of premium cuts of beef.
Fishing Methods: Swordfish are targeted by longline boats when they swim near the surface at night. Monofilament longlines baited with squid and illuminated with chemical lightsticks are set overnight. The gear is set near the surface, in contrast to tuna longline gear, which is typically much deeper. Adoption of these techniques has developed an entirely new Hawaii longline fishery capable of landing at least 2 million pounds of swordfish annually.
Swordfish are occasionally caught at night by small-boat fishermen who are handlining or trolling with lights. Swordfish are also taken as a by-catch in tuna fisheries throughout the island chain.
III. Of Special Interest For Preparation/Quality Control
Shelf Life And Quality Control: Swordfish has an excellent shelf life as a fresh product, lasting up to 3 weeks after capture with proper handling. To ensure good quality and prices for their catch, most Hawa ii swordfish longliners take extra precautions. These include dressing the fish, removing the kidneys, cleaning the belly cavity, and storing the fish in ice. After this initial processing, the fish is often bagged before being stored in ice. Saltwater ice is used by some boats. If swordfish is stored on its back in ice, it will retain a firmer body and will have a better overall appearance. If the fish's head is removed just behind the eye, enough head area will remain for gaffing, resulting in less damage to the body.
The highest quality dressed swordfish is firm and retains rough, grooved skin (sandpaper texture) and metallic silver in its skin color. Flesh exposed along the collar and tail will have red blood lines. The body is undamaged from handling but may show natural marks originating from several causes. For example, longitudinal scratches along the body may be left by sea lampreys, or very shallow oval wounds ("cookie cuts") may be caused by a species of small shark. These marks do not usually penetrate to the flesh. Swordfish caught by longlines can be attacked by larger sharks, which tend to mutilate large portions of flesh. Occasionally, parasites occur that render the adjacent flesh unusable for aesthetic reasons. Simple trimming can correct this problem.
Product Forms And Yields: All sizes of swordfish (10 to 600 pounds) are captured on longline gear. The predominance of 100-300 pound fish in current landings is not surprising because the stock had never been effectively targeted previously.
Most of the Hawaii swordfish catch is exported to secondary processors as a fresh, dressed product without tails (known as "Boston cut"). Although it is common for longliners to market their entire catch at one price, domestic swordfish marketers recognize price differentials for three size classes:
100-250 pounds, or more, dressed weight (known as "markers") -- this size is strongly preferred by restaurants because uniform-sized dinner portions can be cut with a minimum of offcuts and odd-sized portions -- the center sections of large loins are the premium cuts;
50-99 pounds dressed weight ("pups") -- this size is less expensive than markers and the yield of uniformly-sized portions is smaller;
25-49 pounds dressed weight ("rats") -- this size is the least expensive but is generally not used by foodservice or retail buyers who require large portions of uniform size.
Secondary processors provide restaurants and foodservice distributors with loins or "wheels" (large bone-in sections cut through the swordfish body). They also custom-pack loin sections for retail and foodservice chains. "Wheels" have a longer shelf life than loins.
Due to high water content, dressed swordfish can lose a significant amount of weight through drip loss (up to 3% of initial weight for markers, 2% for pups, and 1% for rats).
IV. Of Special Interest To Consumers/Foodservice Personnel
Color, Taste, Texture: The flesh of swordfish may vary from pale to pinkish, probably depending on diet prior to capture. In either case, good quality is indicated by red blood lines (i.e., blood meat) bordering the loin or fillet. Swordfish has a firm texture. When cooked, the flesh is tender and very mild in taste, except for the rind area just under the skin. Swordfish can vary greatly in fat content: fish landed in Hawaii are considered to be comparable in fat content to swordfish from the middle Atlantic region of the U.S.A., where much of the domestic supply originates. Fat content is a more important determinant of swordfish quality and market value in Japan than in the U.S.A.
Preparations: Ideal for grilling, swordfish is in great demand in restaurants and retail markets across the U.S.A., especially along the east coast. Swordfish is one of many species prepared as sashimi in Japan, and its use in raw fish dishes is increasing in Hawaii.
V. Historical Note
Because of the long, distinctive bills which they use to slash prey, swordfish have a well-deserved reputation for ferocity. Several Hawaii fishermen bear scars from landing struggling swordfish. The ancient Hawaiians feared swordfish because they would strike and sometimes pierce fishing canoes.