• Journal of Fisheries and Marine Sciences Education
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• v.8 no.1
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• pp.41-47
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• 1996

The fishing experiment was carried out in order to analyses the mesh selectivity for trawl cod - end in the Southern Korean Sea and East China Sea from June,1991 through December, 1992. The mesh selectivity was examined for the five kinds with opening mesh size, of which having mesh s izes 51.2mm, 70.2mm, 77.6mm, 88.0mm and 111.2mm. In this report, mesh selectivity were taken analyses trawl cod - end for Priacanthus macracanthus. The main results obtained were as follows : 1. The relation equations between total length(TL) and body height(BH), body girth(BG) and body weight(BW) were BH=0.256 TL+2.963, BG=0.620 TL+8.650 and $BW=7.34{\times}10^{-5}TL^{2.6956}$, respectively. 2. 50% selection length and selection factor of trial cod - end with opening mesh size having 51.2mm, 70.2mm, 77.6mm, 88.0mm were 94.8mm, 1.85 ; 159mm, 2.27 ; 204mm, 2.09 ; 217.3mm, 2.18, respectively. 3. Range of opening mesh size from 51.2mm to 88.0mm, parameters of master curve were slope 2.70, intercept - 5.7 and selection factor 2.11.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.1
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• pp.86-94
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• 2004

This study was conducted to mesh selectivity of Beam trawl for shrimps fishing experiment in the coastal waters around Geomundo, South sea of Korea, during from Oct. to Nov. 2002. The selectivity parameters of big head shrimp (Solenocera melantho) have been studied on the covered con-end method. with mesh of 8, 38, 51 and 61 mm. Selection curves and selection parameters were calculated by using a logistic function S=1/(1+exp-(aCL+b)). The mesh selection master curves were estimated by S=1/(1+exp$^{({\alpha}(CL/M)+{\beta}}$), and the optimum mesh size were calculated with (L/M)50 of master curve. Optimum mesh size and selectivity master curves for the southern rough shrimp (Yrachysalambria curvirostris) and smoothshell shrimp (Parapenaeopsis tenella) optimum mesh size and selectivity master curves were estimated by big head shrimp master curves. The results obtained are summarized as follows : Selection parameters '${\alpha}$' and '${\beta}$' of the master curve for big head shrimp were 8.84 and -5.89, and The selection factor of the master curve (L/M)$_{50}$ was 0.67. The optimum mesh size of minimum length for sexual maturity for big head shrimp was 30.7 mm. Estimated (L/M)$_{50}$ for southern rough shrimp and smoothshell shrimp by using the master curve of big head shrimp was 0.73 and the optimum mesh sizes were 25.5 mm for southern rough shrimp and 16.9 mm for smoothshell shrimp, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.4
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• pp.390-396
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• 2011

Southern rough shrimp Trachysalambria curvirostris is exploited mainly by small shrimp beam trawl in coastal regions of Korea. To determine the size selectivity of a shrimp beam trawl for this species, a series of comparative fishing experiments was conducted in the sea adjacent to Geoje Island off the southern cost of Korea in June and November, 2010, using codends with four different mesh sizes(14.2, 17.8, 25.5, and 35.3 mm). The extended Share Each Length's Catch Total(SELECT) analysis method, based on a multinomial distribution, was applied to the fishing data to obtain a master selection curve. The model with the estimated split parameters fit the catch data best. The master selection curve was estimated to be: s(R)=exp(15.183R-7.872)/[1+exp(15.183R-7.872)], where the relative carapace length, R, is the ratio of carapace length to mesh size. The relative carapace length for 50% retention was 0.518, and the selection range was 0.145. The results suggest that codends with a larger mesh size allow more small-sized shrimps to escape.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.1
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• pp.78-82
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• 2009

We describe a catch experiment and the size selectivity of gill nets for male Japanese sandfish (Arctoscopus japonicus) caught near Gosung, Korea. The experiment, which was conducted between October and December 2007, examined six different mesh sizes: 36.4, 39.4, 45.5, 51.5, 53.0, and 57.6 mm. The catch was mostly Japanese sandfish (91.3%) and some others (8.7%). More male Japanese sandfish were caught with smaller mesh sizes and more females with larger mesh sizes. Relationships between the weight and fork length of the male and female Japanese sandfish were obtained. The relationship between the catch (Y) and mesh size of the gill net (X) was $Y=0.1773X^3-5.3753X^2+40.042X+26.846$ ($R^2=0.99$). The selection curve for male Japanese sandfish caught in the experiment was fit, via Kitahara's method, to a polynomial equation, which was $s(R={\exp}\{(-2.1391\;R^3+24.294\;R^2-88.289\;R+105.5)-5.180\}$, where R=l/m, and l and m are the fork length and mesh size, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.28 no.4
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• pp.371-379
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• 1992

In order to analyse the mesh selectivity for the trawl net, the fishing experiment was carried out by the training ship Saebada in the southern Korea Sea and the East China Sea from June 1991 to August 1992. The trawl net used in experiment has the trouser type of cod-end with cover net, and the mesh selectivity was examined for the five kinds of the opening mesh size in its cod-end part. The selection curves and the selection parameters were calculated by using a logistic function, S=1/(1+exp super(-(aL+b))), and in this case, a and b are the selection parameters and L is the body length of the target species of fishes. In this report, the four species of aquatic animals were analysed because the catch data were enough to calculate normally the selection curves and the selection parameters, and the results obtained are summarized as follows: 1. Trachurus japonicus; Selection parameters a and b in each cases of the opening mesh size of 51.2mm, 70.2mm, 77.6mm, 88.0mm and 111.3mm were respectively 0.5050 and -5.4283, 0.3018 and -4.9590, 0.3816 and -7.3659, 0.2695 and -5.7958, 0.2170 and -5.1226. 2. Photololigo edulis ; Selection Parameters a and b in each cases of the former mesh sizes were respectively 0.7394 and -6.1433, 0.3389 and -4.2366, 0.3286 and -5.1002, 0.2543 and -5.0049, 0.1795 and -4.8040. 3. Trichirus lepturus; Selection curves in the opening mesh size of 111.3mm was calculated unnormally. The selection parameters in the other opening mesh sizes were respectively 0.3790 and -5.2891, 0.2071 and -4.9164, 0.1292 and -3.1733, 0.1153 and -3.8497 in the order of former mesh sizes except 111.3mm. 4. Todarodes pacificus ; Selection curve in case of the opening mesh sizes, 70.2mm and 111.3mm were calculated unnormally. In the order cases of the opening mesh sizes, the selection parameters were respectively were 0.5766 and -6.0169, 0.3735 and -5.4633, 0.2771 and -5.7718 in the order of former mesh sizes except 70.2mm and 111.3mm.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.30 no.3
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• pp.172-181
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• 1994

The mesh selectivity of diamond and suare mesh cod-ends at the Southern Korean Sea and the East China Sea were compared for Pampus argenteus, Trachurus japonicus, Trichiurus lepturus. Selection trials were carried out using diamond and square mesh cod-end by trouser type cod-end with cover net. of which the mesh cod-end has four types : A(51.2mm), B(70.2mm), C(77.6mm), D(88.0mm). Selection curves and selection parameters were calculated using a logistic model. The results obained are summarized as follows : 1. Harvest fish : In B. C and D type selection range and fifty percent selection length of the square mesh were about 21mm, 11mm : 12mm, 18mm and 34mm, 5mm higher than those of the diamond mesh, respectively. Selection factor of master curve for the diamond mesh was 1.54 and for the square mesh was 1.68. The optimum mesh size for the diamond mesh was 97.4mm and for the square mesh was 89.3mm, the difference was 8.1mm. 2. Horse mackerel : In A type, selection range was nearly the same for the diamond and the square mesh, but fifty percent selection length of the square mesh was 43mm higher than the diamond mesh. In B. C and D type, selection range and fifty percent selection length of the square mesh were about 6mm, 3mm : 24mm, 21mm and 11mm, 42mm higher than those of the diamond mesh, respectively. Selection factor of master curve for the diamond mesh was 2.37, for the square mesh was 2.77. The optimum mesh size for the diamond mesh was 78.1mm and for the square mesh was 66.8mm, the difference was 11.3mm. 3. Hair tail : In A, B and C type, selection range of the square mesh was about 34mm, 8mm, 60mm higher than those of the diamond mesh. Fifty percent selection length for the diamond mesh was about 5mm, 7mm, 8mm higher than that of the square mesh. Selection factor of master curve for the diamond mesh was 3.11, for the square mesh was 3.48. The optimum mesh size for the diamond mesh was 64.3mm and for the square mesh was 57.5mm, the difference was 6.8mm.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.4
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• pp.281-291
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• 2010

To estimate the mesh selectivity of monofilament and multifilament gill net for Marbled sole, Pleuronectes yokohamae, the field testes were carried out 12 times with five different mesh sizes (86.6, 101.0, 121.2, 137.7, 151.5mm) in the western sea of Korea, 2007-2009. The master curve of selectivity was estimated by the extended Kitahara's method. In the field testes, the total number of species and catch were 26 and 987, respectively. The catch number of marbled sole was 728 and occupied 73.8% in total catch. The optimum values of l/m for 1.0 of retention probability in monofilament and multifilament gill net were estimated 0.288 and 0.307, respectively and l/m was estimated to be 0.189, 0.203, 0.213, 0.222 and 0.230 in case of monofilament gill net and 0.171, 0.191, 0.205, 0.216 and 0.227 in case of multifilament gill net when the retention probability were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively. The 0.5 selection range of multifilament gill net was wider about 1.5 times than that of monofilament gill net according as multifilament gill net was 0.216 and monofilament gill net was 0.148. So the multifilament gill net has a low selectivity than that of the monofilament gill net. To estimate the optimum mesh size on first maturity length 19.5cm of marbled sole, the retention probability value of 0.1 was adopted in consideration of using the gill net for marbled sole at present. The optimum mesh size were estimated to be 103.2mm and 114.0mm in monofilament gill net and multifilament gill net, respectively, on first maturity length 19.5cm of marbled sole.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.42 no.4
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• pp.195-202
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• 2006

To determine the relative efficiency and mesh selectivity of gill net for the Pacific saury, Cololabis saira, a series of fishing experiments was carried out in the Northwest Pacific Ocean from August 13 to October 13 in 2002, using gill nets of different mesh size(30, 33, 35, 37, 39 and 42mm) constructed from two kinds of twine material(monofilament, twisted multifilament nylon web). The relative efficiency of two material gears was expressed as the ratio obtained by dividing monofilament catch by multifilament catch in number. The master selection curve of each material gear was estimated by applying the extended Kitahara's method. The catch of experimental gears is mostly Pacific saury(98.6%), Cololabis saira. The kinds of bycatch are common squid(0.7%), Pacific mackerel(0.6%), etc. Catch comparisons in the two gears showed that monofilament nylon nets are 1.7 times more efficient. The optimum values in monofilament and multifilament gill net for Pacific saury are 8.28 and 8.23, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.4
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• pp.279-288
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• 2005

The mesh selectivity of drum net traps for Buccinum opisoplectum Dall caught in the eastern sea of Korea was described. Several experiments were conducted between July 2003 and March 2004 and the data obtained from the experiment was fitted by SELECT (Share Each Length class's Catch Total) model with unequal fishing and sampling efforts. The selection curve was determined to be 'estimated fishing efficiency' by model deviance rather than AIC. However the fishing efficiency between 20mm and 35mm mesh size did not seem to be different. The $L_{50}$ lengths of the selectivity for the 55mm and 75mm mesh size were 65.4mm and 96.0mm, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.2
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• pp.106-115
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• 2013

A series of fishing experiments were carried out in the western coastal waters of Korea from May, 2006 to September, 2007, using gill nets of different mesh sizes (m=101, 121.8, 152.5, 176.8, and 191 mm) to determine the mesh selectivity of gill net for swimming crab, Potunus trituberculatus. The catch species was composed of swimming crab (87%), Thomas's rapa whelk Rapana venosa (5%), arthritic neptune Neptunea cumingi (2%), Japanese swimming crab Charybdis japonica (2%), marbled sole Pleuronectes yokohamae (1%), pen shell Atrina pectinata, ocellate spot skate Okamejei kenojei, and so on. The carapace length (CL) of each swimming crab caught in the experimental nets was measured. Sponge crab (egg-bearing female crab) was appeared from the end of June to August in the coastal waters. The master selection curve was estimated by applying the extended Kitahara's method. The selection curve showed that the gill nets of larger mesh size allowed more crabs of small carapace size to escape. The optimum value (CL/m) was 0.645 and the CL/m was estimated to be 0.301, 0.354, 0.391, 0.422, and 0.450 when the retention probabilities were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively.