|Hand lines boats operate all over the world, some in shallow waters and some in seas of up to 300 meters deep. |
|OverviewHandlining is just as its name implies, holding a line in the hand while waiting either actively or passively for a fish to take the bait. If there is a bite and a fish takes the hook, it can then be hauled in by hand or by mechanized reel.Fish Technique StructTuna handlining with FADsTuna handlining on free schoolsSpecies EnvironmentThis method is widely varied in the scale and targets. Some handline fishery target large pelagic fish having high individual value, and where high quality is necessary. Major tuna species caught are bluefin, yellowfin, bigeye and albacore. Contrary to this, small tuna and tuna like fish such as skipjack, frigate tuna, bonito, little tuna, black skipjack and spanish mackerels are caught locally near coast but nor for the international trade. The tuna which are normally caught with handlines are not small juveniles schooling near surface but large fish feeding in a small school or individually near surface or at a depth to several hundred of meter. Those are either bluefin or bigeye tuna but also yellowfin and albacore are caught. In small scale coastal handline fishery for local supply catches small tunas and tuna-like fish (e.g. skipjack, bonito, Spanish mackerel) are targeted at the depth above the thermocline.Fishing GearTuna handline is a fishing gear composed of a single vertical line with one barbed hook at the distal point. If several barbed hooks are used, branchlines are connected along the mainline at regular intervals. Specification of the gear varies according to the ideas and traditions of fishermen in different areas of the world. Most fishermen use nylon (polyamide) for their handlines. Line must be strong enough to hold the fish and withstand the combined force of its weight, swimming power and determination to escape. Handlines can be set and hauled either manually or by mechanized reel. It is operated by simply dropping the baited hook into the level of the sea where tuna are found abundant. Handliners generally use natural baits such as squid, chopped pieces of scad mackerel, hairtail and tuna. Natural bait may be replaced by artificial bait or lures but the last ones are less effectives than previous ones.Vessel Overview Handline and pole-lines (hand operated) are, in general, operated from boats, canoes and other small decked or undecked vessels, without any special features for gear handling with the exception of hand or mechanized reel.Handling ModeWet-fish. Careful attention is paid to the high-value capture: when on the deck, fish are kept in the shadow, preferably cover sprayed with sea water to lessen dehydration; when possible, fishermen brought boxes with ice to preserve their catch (there might even be on board individual boxes for large fish).Fishery Production SystemsThe main exploitation form using tuna handlining is artisanal fisheries.Fishing EnvironmentThis fishing technique is used either for catching surface swimming schools of tuna (generally juveniles of large tuna or small tuna-like fish species) or bigger individuals which are usually found swimming in sub-surface or deep waters.Fishing OperationsA line with a hook, usually baited, is lowered into the water from a drifting, anchored or moving boat. Fishing operation can be divided into the following main sequences:|
|1. Baiting hooksNatural bait can be caught in most coastal areas, mostly with Surrounding nets, using frequently, at night, light attraction for squids and other small fish. It is important to keep the bait as fresh as possible; in cases, frozen bait is also used but, in general, its effectiveness proved to be less than with fresh fish. The size of the bait must be adjusted to the hook that will be used and to the target fish; it can be either an entire small fish (or squid) or a slice of it.|
|2. School locatingTuna schools can be located by using acoustic instruments (echosounder, etc.) or by checking FADs.|
|3. Setting handlinesOnce reached fishing grounds, all available means of detection of fish are used, with finally tests of fishing at different depths. After adjustment of the lines to the optimum level, fishing operations begin by jerking constantly the lines to let the fish bite the bait. If there is a bite, the fisherman jerks the line and feeling the fish had been caught, the fisherman pulls the line continuously with care. If there is hard struggle or resistance from the fish, the fisherman must let loose some lengths of the line while simultaneously pulling it if resistance is reduced.|
Fishery OverviewHandlines used mainly by small-scale fishery, can be set either in areas when the experience give chances to meet fish passing by, on free schooling or near-by something aggregating fish such as offshore bank or natural drifting fish aggregating element or artificial FAD (Fish Aggregating Devices).Fishery OverviewThe greatest catches of handline-caught fish are taken by vessels of Indonesia and the Philippines in the Indian Ocean, fishing with FADs. Handling lines are used to catch different species of tunas all around the Pacific Ocean, Indian Ocean, Red Sea, Mediterranean and Atlantic Ocean (Caribbean Sea and off west Africa, Cape Verde, in particular).SeasonalityTuna handlining is a seasonal fishing technique following the migration patterns of target species.IssuesDiscard The type and size of the hooks and, as bait, fish species, conservation status and size, can, to a certain extent, be adjusted to target certain species or sizes of fish. The area and time of fishing, depth of the hooks, type and size of the hooks and sort of bait can be adjusted to the target species; this method is rather selective. However, in certain areas, some incidental catch, in particular sharks, may occure.
|4. Landing catchWhen the tuna arrive on the deck of the boat the hook is removed from the fish mouth. In some cases the fish is immediately gilled, gutted and cleaned with the sea water. Anyway, on the deck, fish are kept in the shadow, preferably with cover sprayed with sea water to lessen dehydration; for conservation of the fish over several hours, boxes with ice are used (even individual boxes for large fish). The hooks are again baited for the next operation.|