SWORDFISH OPPORTUNITY FOR PACIFIC ISLAND COUNTRIES AND TERRITORIES: HOW TO DRESS SWORDFISH FOR THE US MARKET

by Steve Beverly,
Fisheries Development Officer,
SPC, Noumea, New Caledonia

Longline fishing for broadbill swordfish (Xiphias gladius) can be very lucrative but can also be very risky. Swordfish are generally not as high valued as sashimi tuna but, although there is more labour involved, they are easier to handle onboard and during shipping as they are more "durable" than tuna.

They are, however, more expensive to catch. The cost of squid bait and chemical light sticks, both necessary for swordfish longlining, makes operating expenses high for a swordfish trip. Because of these costs, few Pacific Island longline fisheries pursued swordfish in the past.

Costs, however, have come down recently. Chemical light sticks, which used to be priced at around USD 2.00 each, are now about USD 0.30 each. Market opportunities have also improved. A recent court decision in Hawai’i has closed the fishery for all Hawai’i-based longline boats from the equator to the north pole. The Hawai’i longline fleet was a major supplier to the US mainland market. The US market is still very hungry for swordfish, however. What this means to the rest of the Pacific is that this could be a good time to be getting into this fishery.

Stocks of swordfish have been identified in or near numerous Pacific Island fisheries, including those of Fiji Islands, Tonga, French Polynesia, and New Caledonia. Longline boats in the region can easily be converted to make the switch from tuna longlining to swordfish longlining. All that is needed, besides squid bait and light sticks (chemical or electric) and different hooks (9.0 swordfish hooks), is a switch in fishing strategy and knowledge of how to process and market swordfish.

The biggest difference in fishing strategy is that swordfish gear is set at night, nearer the surface than tuna gear, and is hauled in the morning. This is just the opposite of tuna longline gear, which is generally set in the morning and hauled in the evening.

Fishing is also done around the full moon, and swordfish boats are usually back in port during the new moon. Additionally, more attention is paid to sea surface temperature and boats search for temperature breaks, or places where the temperature rises or falls one or more degrees (Celsius) in a short distance.

The main marketing concern is access. In the past, swordfish have been suspected of having unacceptable levels of methyl mercury in their flesh, usually in larger fish only. Different countries have different acceptable levels, but generally, any amount above 0.5 to 1.0 parts per million (ppm) is too high. To enter the US market a certain number of fish must pass mandatory testing, after which the exporting company will be issued a "Green Card" and all further shipments will be allowed entry but still be subject to spot testing. The best way to get a Green Card is make contact with a fish wholesaler in the US who deals in swordfish and has had overseas importing experience.

Generally, about 500 kg of fish weighing between 30 and 100 kg each and sent in three separate shipments need to pass the mercury tests before a Green Card is issued. Aside from passing the test for mercury, one of the most important concerns for overseas markets is proper on-board handling of the catch.

US markets have certain guidelines for dressing swordfish. Fresh swordfish are marketed as fully dressed trunks, that is, all fish are headed and gutted and finned. The main focus of this article is to outline the proper procedures for on-board dressing of swordfish for the US market.

As with other pelagic longline species, swordfish should be gaffed in the head, not the body. After the fish has been gaffed and landed, it should be clubbed or spiked if it is alive, although swordfish usually come up dead on the hook.

Bleeding is not necessary. The hook should be removed and the fish should be laid out on a padded surface such as a carpet for dressing. Swordfish do not bruise easily like tuna but care should still be given not to damage the flesh or mark the skin unnecessarily by rough handling. The necessary tools for dressing the fish and a sea water hose should be nearby. Tools include: a saw for cutting the head and fins, a sharp knife for cutting the gill membranes and anal opening, and a stiff brush or large spoon for scraping away blood and slime. Gloves should be worn at all times when handling swordfish.

The first step is to remove the head. This is done by cutting straight through the head at a 90 degree angle to the body exactly on the line formed by the second gill cover (Fig 1). This cut removes the head but leaves the pectoral girdle intact. This is important for preserving the overall shape of the dressed fish. It is also important not to remove too much flesh from the dressed fish. A cut farther back would waste several kgs of good meat. A cut farther forward would result in a higher air-freight bill.

The next step is to remove all fins (Fig 2). This is usually done with a meat saw but can also be done with a heavy chopping knife. The tail is cut off in one piece just behind the caudal keel (Fig 3). There is an indentation on both sides of the fish between the caudal keel and the tail. This indentation should be used as a line to guide the cutting. The result is what some buyers call the "Boston cut". After this cut is made, the fully dressed trunk can still be lifted by a tail rope as the caudal keel will hold the rope in place.

The gill covers are cut off next (Fig 4) and the gill membranes are cut all the way around (Fig 5).

Then the fish is turned so it is facing belly up and a circle, or "donut hole", is cut around the anal opening without cutting through the intestine (Fig 6). A cut is then made from the donut hole forward along the belly and ending just behind the pectoral girdle (Fig 7). Care should be taken not to cut through the pectoral girdle, as the fish will lose its shape if this is cut. The gills and guts can then be pulled out in one piece through the front opening to the body cavity (Fig 8). All loose bits of gill membrane tissue should then be cut away.

The next procedure is to thoroughly clean the inside of the body cavity. This is accomplished by first cutting away the bloodline from the backbone (Fig 9). Parallel cuts can be made on either side of the bloodline and the tissue can be pulled away in one piece. Care should be taken not to cut into the flesh on either side of the backbone. All remaining tissue and blood needs to be brushed or scraped away from the backbone and the gut cavity lining using a brush or large spoon and lots of seawater for rinsing (Fig 10).

The gut lining should be free of slime, and clean white bone should be showing along the backbone (Fig 11). The entire trunk should be rinsed but the outside does not need to be scrubbed. The result is a fully dressed trunk ready for icing and ready for the US fresh swordfish market (Fig 12). Dressed trunks are usually placed in polyethylene "body bags" before being iced. The body bag prevents melt water from the ice from seeping into the flesh and also helps to preserve skin color.

Figure 1: Cut head on line of 2nd gill cover	Figure 2: Remove all fins	Figure 3: Cut tail behind caudal keel	Figure 4: Cut gill covers
Figure 5: Cut gill membranes	Figure 6: Cut circle around anal opening	Figure 7: Slit belly up to pectoral girdle	Figure 8: Remove gills and guts
Figure 9: Cut bloodline from backbone	Figure 10: Brush, rinse, removing all slime	Figure 11: White bone should show	Figure 12: Fully dressed trunk ready for icing

Fresh swordfish trunks can be shipped in the same "wet lock" cartons that are used for tuna, or they can be packed directly into an LD-3 airline container, as long as the container is lined with waterproof insulation. Requirements may differ so airlines and freight forwarders should be consulted on specific shipping instructions. The US market labels fully dressed swordfish trunks according to their weights. Fish over 100 lbs (45 kg) are called "markers". Fish between 30 and 100 lbs (14 to 45 kg) are called "pups" and fish under thirty lbs (14 kg) are called "puppies" or "rats". The most desired fish are markers.

Note: all photos were taken during two swordfish trips on the Navimon (New Caledonia) longliner, F/V Iaai Pêche. Many thanks to the captain and crew.

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