Chapter 6 preface: Tuna longline fishing



Before fishing operations started each day the deck had to be laid out properly. This included stringing the mainline from the reel back aft to the line shooter where the baiting took place, and arranging all buoys, floatlines, radio buoys and branchline bins in their proper places. The right number of bait boxes had already been taken out of the fish hold. After the vessel was under way in the setting zone on the desired course and speed, the first radio buoy was thrown over. As the mainline went out over the stern through the line shooter, floatlines and baited branchlines were clipped on at appropriate intervals. The spacing used was usually about 40 hooks per mile (20 hooks per kilometre), and 20 hooks per basket. At 40 hooks per mile, the interval between hooks is about 25 fathoms (50 m).

The branchlines need to be far enough apart so that they cannot tangle with each other, and so that during hauling, one can be coiled before the next one comes up. The line was deployed just to the starboard side of centre (Figure 12 shows the position of the line shooter), the baited hooks were thrown off the port side (Figure 12), while the floatlines were thrown off the starboard side (Figure 13). The branchline bins were positioned between two crewmen at the stern. One man, the baiter, removed a hook from its snap, baited it by piercing the hook down into the body of the baitfish just in front of the dorsal fin going from the left to right side, and then threw the baited hook at the proper interval. The species of bait used during the fishing operations were Maro Aji (Decapterus spp.) and Iwashi (Sardinops melanosticta).

The baiter set the pace. The other man, the snapper, then snapped the clip, which he had removed from the rack, onto the mainline. It was important for the snapper to snap just the clip as the baiter threw the bait. To avoid tangles, branchlines were thrown so that they would lie perpendicular to the mainline. When the desired number of the hooks had been thrown, the last radio buoy was attached and thrown over. The boat was stopped for this and a loop was tied into the mainline. Positions at the start and finish of the set were taken from the GPS, and were written down or marked on the chart. In addition, current, boat drift and wind direction were always noted. This helped in locating the line after 6–7 hours of soaking. The signal from the radio buoys was always checked.


After a soak of 6–7 hours the line was recovered. The deck had to be rearranged somewhat  and tools laid out before hauling commenced. The first radio buoy was then recovered and the end of the mainline detached and passed through the blocks and secured to the reel. If the mainline was cut at the end of the set, a blood knot was used to re-attach the two ends. Blood knots were also used if any bad tangles or shark-damaged sections of the mainline needed to be cut out. Once the line was secured to the drum, hauling commenced.

The main man on the deck was the roller man, who operated the control valve for the reel, engine controls, and steered the vessel. His job was to control the speed at which the line was recovered and to unsnap all branchlines and floatlines as they came up. Another crewman, the coiler, stood directly behind the roller man. His job was to take each snap from the roller man and coil the branchlines into the branchline bin in front of him.

Other crew stood behind the coiler. Their job was to assist the coiler with branchlines, or pull in floatlines, coil and stow the lines, and stow the floats. This whole process was done without stopping (until a branchline holding a fish was reached) as the snaps could be removed from the mainline while it was still moving. The roller man kept one hand on the line (this also allowed him to feel if a fish was on the line) and the other hand on the control valve. Another man tended to all fish; spiking, bleeding, cleaning and icing.

When a fish was encountered, the roller man yelled ‘fish!’, stopped the vessel and turned to port (so the vessel would not go over the line). The coiler usually stood by with a gaff as the roller man pulled the fish in by hand. The snap was not removed from the mainline until the fish had been gaffed and was on board, unless a lazyline, or playline, had been used, as was necessary with a very active, large fish. After the fish was on the deck, hauling resumed. It was better to keep the vessel and line moving once hauling had started, as stopping the vessel for any length of time could have put enough tension on the line to break it or to twist the mainline, thus tangling the branchlines. After the final radio buoy had been hauled in, the end of the line was secured onto the reel.

As a tuna was pulled up to the surface near the rail, one or two men gaffed it and lifted it on board (Figure 17), taking care not to gaff the body or to injure the heart. The first gaff (if the fish was alive) would necessarily be somewhere in the head, while the second gaff could then be stuck into the open mouth. Tuna should not be gaffed in the lower jaw, as this tend, to destroy the isthmus connecting the gills to the lower jaw, which gives the iced fish a distorted shape, and could damage the heart. As the gaffed fish was hauled aboard, a third man would grab the tail to enable the fish to be lowered gently to a waiting rubber pad. If the landed fish was thrashing, two things could be done. If the thrashing was violent and likely to damage the fish or injure the fishermen, the quickest way to settle it down was to hit it with a firm blow to the top of the head with a wooden club or ‘fish bat’. This blow only stuns the fish and does not kill it. If the fish was only moving slightly, covering the eye with a gloved hand would usually calm it down. The same club was then used to remove the hook. This was done by grabbing the branchline near the hook and pulling it tight, and then striking the ring end of the hook with the club.

After the hook was removed, the fish was spiked with a stainless steel ‘tee spike’. A long screw driver would work just as well. The spiker straddled the fish with one foot on either side just behind the pectoral fins, with the fish on its belly, held firmly in place with the spiker’s legs. The spike was inserted in the soft spot between the eyes and pushed back at about a 45 degree angle into the skull. The brain was then destroyed by stirring the spike around. If spiking was done properly, the fish shuddered violently and then went limp, with its mouth agape and its eyes not responding to touch. The skin colour changed from blue to grey.

The fish were bled by making cuts on either side of the fish in the pectoral fin recess. The cut has to be perpendicular to the body axis of the fish or the blood vessels are likely to be missed. After the blood vessels were seen to be bleeding a cut was made in the gill membrane on one side of the fish, at about the mid-line (Figure 18). Further cuts were made during bleeding, on either side of the tail between the third and fourth tail scutes.

After bleeding was finished, the gills and guts were removed. This was done by first cutting a ‘doughnut’ cut around the anal opening and then making a slit from this cut forward about 15 cm (6 in) along the belly. A cut was made on each gill cover at the top going forward to the skull. This allowed the gill covers to be opened more widely for easier removal of gills and guts. Next, all gill membranes were cut loose from the pectoral girdle and the gills were cut loose from the head by carefully cutting the membranes connecting the gills to the skull and to the lower jaw. It was important not to cut the isthmus at the throat during this operation because the fish would become distorted during icing, as the back would shrink more than the underside.

After the gills and guts had been removed, all loose tissue was cut away from the inside of the gill cavity and all membranes were cut away from the gill collar. Then the inside of the cavity was scrubbed with a stiff brush made from monofilament and flushed with plenty of seawater. The kidneys, along with any coagulated blood, were scrubbed away from the base of the skull. At this point, the backbone could be seen where the kidneys used to be. Lastly, the entire fish was rinsed one final time to remove any debris or blood. During the whole process, sea water was constantly being used to flush and rinse the fish. Once the fish was clean, it was packed in ice so that the fish was straight with its belly down.

By-catch species were handled and cleaned in a similar way, with marlin having their head removed as well (headed and gutted). Small fish were not cleaned, but iced in the round or whole. Live sharks were released by cutting the trace, while dead sharks had their fins removed and retained.

It was important to keep everything that came into contact with fish clean at all times. After each fish had been handled, all tools, including the gaff heads, spikes, knives, and mats, were rinsed with seawater. At the completion of each fishing trip, the fish hold was emptied and scrubbed with seawater and a mixture of soap and bleach. The soap and bleach were rinsed completely away after washing.