• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.3
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• pp.202-212
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• 2020

In order to replace sardine baits for octopus pot, an efficacy experiment to lure with alternative bait (fermented skate or chicken skin in artificial crab or northern clam) pots and sardine pot were conducted in a circular water tank. The soaking time of the sardine bait was divided into two categories: six days or less and seven days or more. The behavioral response of octopus to the artificial bait pots and sardine pot were investigated. In the comparison of the luring effects between pots with fermented skate inside artificial crab or northern clam and sardine pot, the pot with artificial crab + fermented skate had better results than the other pots in the section distribution (31.6%) and the number of times the pot was entered into (20.0%) (p > 0.05). In the comparison of the luring effects between pots with chicken skin inside artificial crab or northern clam and sardine pot, the pot with northern clam + chicken skin had better results than the other pots in the section distribution (22.6%) and number of times the pot was entered into (55.6%) (p < 0.05). The results were also better compared to those of pot with artificial crab + fermented skate. From these results, it seems that in the luring effect aspect, sardine bait can be replaced with artificial bait consisting of chicken skin inside northern clam.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.3
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• pp.190-197
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• 2019

This study investigated the luring effect of the sardine bait, which is used to catch octopus with pot, as the preliminary study for the development of alternative bait for octopus pot. The soaking time for bait was divided into "5 days or less" and "11 days or longer" The number of times octopus entered the pot with bait and the empty pot was investigated under dark adaptation and light adaptation processes and the distribution of tank section was investigated under light adaptation process. The case of "11 days or longer" sardine soaking time showed higher rate of distribution in the section of pot with bait compared to the case of "5 days or less" In the case of "5 days or less" soaking time, the number of times the octopus entered the pot with bait was similar to that it entered the pot without it even during dark adaptation and light adaptation. However, in the case of "11 days or longer", the octopus entered the pot with bait more quickly than the pot without bait and more frequently during dark adaptation hours. There were cases where the octopus did not enter any pot. In the case of "5 days or less", with less decomposition of baits, the octopus entered the empty pot more during light adaptation process, and it appeared that the pot was used as a hideout.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.43 no.4
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• pp.301-309
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• 2007

In order to develop the artificial bait of trap for swimming crabs, the attracting effect was analyzed in the duration time of attracting effect, preference and shape recognition to the bait in the water tank and field experiments. According to the result which investigated the mean entrapped number of swimming crabs into the trap for each bait(mackerel, sardine and anchovy) in water tank experiments, the mean entrapped number was found to be higher in the trap with mackerel(6.9 ind.; 23.0%) than in other traps with sardine(5.2 ind.; 17.3%) and anchovy(3.4 ind.; 11.3%). In addition, the mean entrapped ratios of swimming crabs into the traps for 3 kinds of baits were estimated to be over 80% all in 5 hours after soaked in the water tank. For preference of swimming crabs to 3 kinds of baits, the trap with mackerel(6.9 ind.; 23.0%) was evaluated to be higher than the traps with sardine(2.8 ind.; 9.3%) and anchovy(0.2 ind.; 0.7%). In the field experiments, the mean entrapped number of swimming crabs into the trap with mackerel and sardine were found to be similar as 120 and 118 ind., but the trap with anchovy was only 85 ind.. According to the result which investigated the shape regnition of swimming crabs to the bait used mackerel, divided into 8 pieces, 16 pieces and grinded mass in water tank experiments, the mean entrapped number of swimming crabs into the traps that includes the mackerel divided into several pieces was significantly decreased. Moreover, by the presence of skin of mackerel for bait, there was a great difference in the entrapped number of swimming crabs. Therefore, it was thought that the swimming crab was attracted to the bait and entrapped into the trap would indicate that not only the chemical stimuli such as the attactant, but also the visual stimuli such as the shape recognition to the bait might be closely related.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.2
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• pp.185-190
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• 1998

The aim of this study was to develop the artificial trap baits being able to replace the natural anchovy or sardine baits. The fishing trials for evaluating the fishing efficiencies of the artificial baits were conducted with commercial traps at coastal areas near Tongyoung, southern Korea. The preferable artificial baits which were made of minced anchovy, sardine, mackerel, or fish surplus products mixed with wheat flour into dry or wet pelleted or crumbled types, were showed some merits as the following. \circled1 Fishing efficiencies of the artificial baits were same or little higher level than that of the natural bait anchovy; \circled2 bait cost were same or little lower level; \circled3 dry artificial baits stocked in the room condition showed good fishing efficiencies; \circled4 making of artificial baits were very simple; \circled5 there were no harm to the fish and little pollution to the environment; \circled6 the releasing rate of attractants in the artificial or natural bait showed similar patterns. The artificial baits using the fish by-products which were vacuum freeze-drying extract of boiled anchovy or tunas extract, showed lower catches in the conger eel, Coner miriaster, but similar catches in the crabs, mainly Charybdis japonica, to the those of natural anchovy bait.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.4
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• pp.317-325
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• 1990

The attraction activity of the natural baits for sea eels(Astroconger myriaster) was surveyed by using fishing traps in the 3 different fishing ground of southern coastal waters of Korea. Twenty four different baits were experimented and weight for each bait was 50g, the optimal minimum weight owing to our preliminary test. Among the above 24 baits, anchovy(Engraulis japonica), sardine(Sardinops melanosticta), or marine worms(Neanthes japonica)were most effective. In case of sardine bait, the body showed higher attraction activity than the head or viscera and the builded juice of anchovy or sardine showed higher attraction activity than spoiled one.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.1
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• pp.1-8
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• 2004

The single line hook fishery for giant pacific octopus, Parotopus dofleini is one of the important in coastal Kangwon-do of Korea, where was caught an average of 4,000 ton during the period of 1996~2000. The fishing gear is consisted of a single buoy line, a buoy and a hook. In this study, the responses of giant pacific octopus to single line hook gear were examined in an experimental tank using a video camera in order to know hooking mechanism and improve hook. Giant pacific octopus tend to envelop the bait with their arms by rush or slowly swimming towards it. When they rush to the bait, they show much feeding behaviour as withdrawing after enveloping the bait using two arms. But when they approach with slowly swimming to bait, they show feeding behaviour as stopping after enveloping the bait using one arm. and then, the highly hooking rate appeared more often in the case of latter then former. The average feeding time on a sardine, giant pacific octopus and pork fat showed the range of 1 to 30 min, 10 to 50 min, and 50 min to over 1 hour, respectively. This indicates that it takes longer time for giant pacific octopus to eat the tough meat than the soft meat. The performance concerned with hooking showed that the 'B' type hook with a short shank was more favorable than the 'A' type hook with a long shank. However, the 'A' type hook has the advantage of easy dropping out caught octopus, compared to the 'B' type.

• Korean Journal of Ichthyology
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• v.20 no.2
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• pp.105-111
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• 2008

A pelagic tuna longline research cruise in the eastern and central Pacific Ocean from September to October of 2006 was conducted to compare catch rates with the use of different hook type and bait combinations. Traditional tuna hooks (J 4) and three circle hook types (C15, C16, C18), along with five bait types (chub mackerel (CM), jack mackerel (JM), milkfish (MF), sardine (SD), and squid (SQ)) and hook number as a proxy for hook depth were evaluated for their effect on bigeye tuna catch rates (fish per 1,000 hooks) using Generalized Linear Models (GLMs). Results from 28 sets indicated significant differences in bigeye catch rates between individual longline sets and hook number. The GLM explained 33% of the deviance in bigeye catch rates with these two factors. An alternative model formulation included bait type which had a small effect (explaining 2.7% of the deviance) on catch rates. Hook type had a negligible and non-significant effect in the GLMs. These results indicate that all of the hooks and baits tested are equally effective at catching bigeye tuna and that hook number (depth) was the paramount operational factor in explaining bigeye tuna catch rates.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.4
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• pp.157-162
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• 1987

The basic experiments on the plastic sea eel pots used in fishing were carried out in order to investigate the elasticity of the funnel ribs, hydrodynamic resistance, sinking time and diffusion of the bait from June to October, 1987. The elasticity of the bamboo funnel ribs was higher than that of the polypropylene ribs up to the load 150g. The hydrodynamic resistance R (kg) of the pots towing to the head direction horizontally in relation to towing velocity V (m/sec) was expressed as following formula; R=0.36V super(2.01) and coefficient of drag C sub(D) was 0.52. The sinking times of the covered pots by tape fully or partially were late 1-2 second than the typical pots within the water depth 7.5m. The diffusion tendency through the covered pots using dye and sardine extracts solution was concentrated to the entrance more than the typical pots. However, fishing efficiency as number and weight of fish per pots for nine times fishing operation was revealed no difference between the covered pots and the typical pots.