• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.1
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• pp.6-12
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• 1998

The moving behaviour of Yellowtail Seriola quinqueradiata schools in the main-net of a large scale set-net was investigated in relation to the catching function of the funnel-net by a scanning sonar. The investigation was took place in the Kishihata set-net fishing ground located in Nanao city Ishigawa prefecture, Japan from Nov. 9 to Nov. 13, 1992. The obtained results are summarized as follows; 1. Fish schools showed the greatest number at the playground in the morning and at the bag-net in the afternoon. The fish schools remained long time in the main-net. 2. The rate of fish school through the funnel-net was smaller than that of fish school which is though the playground and bag-net. Because the Yellowtail school changed the shape of school in passing the funnel-net. 3. The rate of entering the bag-net was 24%, among the fish school heading to the outer funnel-net. But, the rate of escaping to the playground was 27%, among the fish school heading to the inner funnel-net. It seems that the structure of the outer funnel-net was not enough to lead the fish to the bag-net. However, the structure of the inner funnel-net was very effective at preventing escape. 4. It is appropriate to haul the net in the morning in considering the number of accumulated fish in the bag-net during the survey.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.1
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• pp.13-20
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• 1998

The moving behaviour of Yellowtail Seriola quinqueradiata schools in the main-net of a large scale set-net was investigated in relation to the catching function of the funnel-net by a scanning sonar. The investigation was took place in the Kishihata set-net fishing ground located in Nanao city Ishigawa prefecture, Japan from Nov. 9 to Nov. 13, 1992. The obtained results are summarized as follows; 1. Fish schools showed the greatest number at the playground in the morning and at the bag-net in the afternoon. The fish schools remained long time in the main-net. 2. The rate of fish school through the funnel-net was smaller than that of fish school which is though the playground and bag-net. Because the Yellowtail school changed the shape of school in passing the funnel-net. 3. The rate of entering the bag-net was 24%, among the fish school heading to the outer funnel-net. But, the rate of escaping to the playground was 27%, among the fish school heading to the inner funnel-net. It seems that the structure of the outer funnel-net was not enough to lead the fish to the bag-net. However, the structure of the inner funnel-net was very effective at preventing escape. 4. It is appropriate to haul the net in the morning in considering the number of accumulated fish in the bag-net during the survey.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.1
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• pp.1-8
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• 2005

In order to find out the environmental factors influencing movement of common grey mullet, Mugil cephalus in funnel net fishing ground of the Dolsan-do, Yeosu southern sea area, the oceanographic factor such as the water temperature, isobath and tidal current were observed respectively, the water temperature was compared with the amount of common grey mullet caught by funnel net. Also, to investigate the movement direction of common grey mullet in same sea area, 160 common grey mullets of body length 22 to 51cm caught at funnel nets of the Dolsan-do southern sea area were marked and then released at 5 positions in 5 times. The results obtained are summarized as follows : 1. The water temperature at the funnel net fishing ground of Dolsan-do in 2002 was ranged from 6.9 to 27.4$^{\circ}C$. The water temperature was displayed a maximum value in August to increase from March and a minimum value in February of the ensuing year to decrease from September. The catches of gray mullet caught by funnel net were generally abundant from March to September, but decreased sharply from October. The optimum range of water temperature for the funnel nets fishing was situated between 15.0 to 25.0$^{\circ}C$. 2. The isobath from 6m to 13m in coast sea set up funnel nets were densely distributed and the depth more than 14m of isobath were widely spreaded to the open sea at Dolsan-do southern sea area. 3. The tidal current of the coast sea set up funnel nets flowed southward and northward along the coast ato ebb and flood tide respectively. The direction of tidal current to the open sea was southeast at ebb tide with the mean speed 43cm/sec, but northwest at flood with the mean speed 25cm/sec. 4. The recapture rate through the experiment duration showed 9.4%. The recapture rate in Gyedong area was very high value with 33.3% as compared with others. The movement of common grey mullet in Dolsan-do southern sea area trended toward a inner bay and north bound mainly.

• Nuclear Engineering and Technology
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• v.52 no.8
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• pp.1724-1731
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• 2020

Low cycle fatigue tests on the hydrogenated welding seam of Zr-Sn-Nb alloy at room temperature and 360 ℃ had been carried out by using the funnel-shaped flat specimens. The relationships between nominal stress & strain directly measured across the funnel and local stress & strain at the root of the funnel are given by considering cyclic plasticity correction. The results show that the fatigue resistance of welding seam at room temperature is only slightly better than that at 360 ℃. Probabilistic fatigue life curves are obtained by using a two-parameter power function.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.42 no.3
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• pp.158-168
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• 2006

A study on the species composition and seasonal variations of fishery creatures caught by a funnel net was carried out in the coastal water off Dolsan Island, Yeosu from 2002 to 2003. During the study period, a total of 23 fishery creatures species were caught. Seabream(Acanthopagrus schlegeli), sea bass(Lateolabrax japonicus), mullet(Mugil cephalus), puffer(Takifugu niphobles) and rockfish(Sebastes inermis) predominated. These five species accounted for 85.1% of the total number of fishery creatures caught. Seasonal peaks of number of species occurred in summer, while those of number of individuals occurred in autumn. The lowest number of species and individuals were observed in winter. The large annual variation of diversity indices were observed from May to August. These large annual variation of diversity indices were mainly due to predominance of seabream, sea bass and mullet which accounted for most of all fishery creatures caught. The seasonal variations of fishery creatures showed that sea bass and mullet were caught mainly from spring to summer, seabream and puffer were caught mainly in autumn, and rockfish and brotula(Hoplobrotula armata) were caught mainly in winter.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.1
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• pp.37-46
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• 2004

In order to increase fishing efficiencies of the fyke net used in the coast of Jeju Island, water tank experiment was caried out entering and escaping behavior using nets that were reduced to 1/20 of the size of the full scale fyke net and were improved to have antrance structure, and mackerel Scomber japonicus as experimental fish. The results of measurement are as follows : 1. Fish school behavior in the main net was showed two different patterns : swimming in a circle in the right space of the main net and swimming back and forth in ellipse in the right and left space. 2. The swimming speed of mackerel school was 23.9. 12.6 and 32.0cm/sec in the center space, right space of main net and in the mouth 3. The entering rate of fish school was 40% in net with 35cm length of the upper and funnel net in the mouth of fyke model net and 49% in conventional type fyke model net. 4. The escaping rate of fish school was 10% in net with 35cm length of the upper and funnel net in the mouth of fyke model net and 69% in conventional type fyke model net. 5. The remain rate of fish school was 90% in net with 35cm length of the upper and funnel net in the mouth of fyke model net and 31% in conventional type fyke model net.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.4
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• pp.324-334
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• 2010

This investigation was carried out to research on the actual states for bycatch and discards of catches caught by funnel net from December, 2007 to June, 2010. Fishing grounds were Manheung-dong and Ocheon-dong in the coastal waters of Yeosu. The number of the investigation was 21 in Manheung-dong and 7 in Ocheon-dong fishing ground. In Manheung-dong, the species of catches were 26 of fish, 6 of cephalopod and 5 of crustacean. In Ocheon-dong, the species of catches were 25 of fish, 6 of cephalopod and 4 of crustacean. In the two all fishing grounds, the largest amount of species was revealed as gray mullet. Among these catches, the number of non marketable species that were classified and discarded ones, were 9 in Manheung-dong and 7 in Ocheon-dong. Also, among the marketable species which were small entity or too tiny catches to commercialize and not fresh ones were discarded. The proportion that they dominate in the whole catches was 37.1% in the number of catches and 5.4% in the weight of catches in Manheung-dong, and 6.9% in the number of catches and 0.3% in the weight of catches in Ocheon-dong. In case of Manheung-dong, the monthly discarding proportion was the highest with 59.4% in the number of catches in may and 17.6% in the weight of catches in November, and in case of Ocheon-dong, the both of them were the highest in February, with 28.0% in the number of catches and 5.1% in the weight of catches.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.1
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• pp.1-11
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• 2017

Fishing pots are one of the important fishing gears in our coastal and offshore fisheries. In terms of a sustainable use of marine resources, there are concerns about the ghost fishing by lost pots. It is reported that 10 to 70% of the pots are abandoned or lost annually. This study is to compare the catching efficiency of drum type whelk pots that are made of biodegradable nets to those made of the ordinary nets, in the eastern coast of Korea. Five types of drum pots were used with combination of biodegradable nets and ordinary (PA, PE) nets applied to the main and funnel parts of the pots: pots with biodegradable nets (Bio+Bio); pots with PE net (PE+PE); pots with body and funnel made of biodegradable nets and PE nets respectively (Bio+PE); pots with body and funnel made of PE nets and PA nets respectively (PE+PA); pots with body and funnel made of PE nets and biodegradable net respectively (PE+Bio). Field experiments were conducted from June $18^{th}$, 2015 to August $7^{th}$, 2015 using a commercial fishing vessel in the Uljin waters on the eastern coast of Korea. Two fleets of pots with one hundred in each, 20 pots of each type, were casted for 8 to 15 days to analyze their catching efficiency. The catch of target species, whelks, was 202,563.0 g with catch rate of 38.7% of the total catch, while the bycatch was 320,709.7 g with the rate of 61.3% of the total catch. The catch of whelks was the highest in the Bio+PE pots (46,020.3 g), followed by the Bio+Bio pots (42,027.5 g), the PE+Bio pots (41,849.9 g) and the lowest being PE+PE pots (38,054.2 g). Compared to the conventional pots, the pots with biodegradable nets on the body or entrance part had slightly higher catch rate for both the target species and the bycatch. The PE+PE had the lowest catch rate. There is no significant difference in catch between the pots with biodegradable nets and the ordinary nets for the target species such as Buccinum opisthoplectum, Neptunea eulimata, Buccinum striatissimum. Consequently, using biodegradable nets for the conventional whelk pots can reduce ghost fishing by lost gears while keeping the performance of the pots.

• Korean Journal of Environmental Biology
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• v.36 no.2
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• pp.99-106
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• 2018

Extensive monitoring of aquatic organisms in rice paddy fields has been difficult due to laborious sampling methods such as quadrat sampling using a hand net. This study aimed to analyze temporal and regional community compositions of aquatic organisms collected with a less time-consuming sampling method. This method involved using submerged funnel traps in rice paddy fields. Submerged funnel traps were useful for capturing taxa containing species that are indicative of environmental changes and highly mobile species that feed on waterbirds. Fifteen taxa including Ampullariidae, Cobitidae, Chironomidae, Hydrophilidae and Dytiscidae determined the community compositions. Among the major taxa, only Chironomidae resistant to environmental disturbances represented temporal variations of aquatic organism communities in rice paddy fields. Ampullariidae, Dytiscidae, and Hydrophilidae, which are prone to be affected by anthropogenic activities, differed among regions.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.2
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• pp.71-77
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• 2001

In order to find out the environmental factors influencing the catch of fyke nets in the coastal waters Yosu, the oceanographic factors, i.e., the waters temperature and the salinity were observed respectively from April to November in 1999, and each of them was compared with the catch of common mullet, Mugil cephalus by fyke net. The results obtained are summerized as follows : 1. The water temperature was ranged from 13.0 to $25^\circ$C and water temperature increased from April to August and decreased on September to November. 2. The range salinity in the fishing grounds was from 28.6 to 33.8$\textperthousand$, and salinity was high from April to June. From July, however, the salinity decreased to continue a low value still september. 3. The catches of common mullet caught by funnel net were the highest in may and the smallest in November. The ranges of optimum water temperature for the funnel nets fishing was 15.0 to $16.0^\circ$C, the ranges of optimum salinity for fishing varied between from 32.6 to 33.8$\textperthousand$.