• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.46 no.3
• /
• pp.204-213
• /
• 2010

Test fishing was carried out using six kinds of different mesh sizes (20, 22, 24, 28, 35, 40mm) for springnet-pot to study bycatches according to the mesh size and catches survey was done for another one (mesh size : 22mm, entrance round : 350mm) in Geo-je & Tong-young waters of Korea. On the first sea experiment, it was thought that suitable mesh size of spring-net-pot catching conger-eel over 35cm with decreasing the catches of conger-eel (Conger myriaster) below 35cm was 24mm. On the second sea experiment, commercial catches were crabs (Charybdis bimaculata), octopus minor (Octopus variabilis) and others including conger-eel, and catches proportion was 60% of total catches weights. There was no big difference for the monthly catches. Self-consumption catches were 9 species including conger-eel below 35cm holding 50% of catches in the side of weights. There were 40% of bycatches for the catches weights and 63% for catches numbers in the 22mm mesh size of spring-net-pot having entrance round over 140mm. It showed that 50% of catches weights were discarded.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.42 no.1
• /
• pp.1-10
• /
• 2006

Present study was conducted to improve the spring frame net trap for conger eel, Conger myriaster which prevents by-catch and protects immature fish. A series of comparative fishing experiment was carried out in water off the south-east coast of Korea from Nov. 2004 to Jul. 2005. And analyzed the amount of catch, by-catch rate, and CPUE, etc. of experimental traps which were the spring frame net traps, sorted four types of flappers. And the compared gear was a plastic conger eel pot. The conclusions were as follows. By-catch rates of spring frame net trap with the compressed flapper bound by nylon mono-filament was about 0-3%. CPUE of spring frame net trap with the compressed flapper was about 50-60% lower than that of traditional and plastic pot. And in case of conger eel that the total length is over 350mm, CPUE was little different on each type of flapper of every mesh size.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.52 no.1
• /
• pp.9-16
• /
• 2016

This study was conducted to analyze fishing capacity and bycatch by mesh size and entrance size of spring net pot conducted by water tank and field experiment. The water tank experiments were conducted by using traps with mesh size of 22 mm and entrance size of 120 mm and 140 mm, respectively in the water tank of NIFS. The field experiment was conducted using 5 kinds of spring net pot with mesh sizes of 20 mm, 22 mm, 35 mm and entrance size of 120 mm, 130 mm, 140 mm, 360 mm by coastal trap fishery vessel operating around the area of Geoje island. In the result of water tank experiments, the catch of conger eel was 1.5 times higher when using trap with entrance size of 140 mm than that of 120 mm. In the field experiment, when using same mesh size, the larger the entrance size, the higher amount of conger eel catch, bycatch and number of bycatch species. When using the same entrance size, the larger the mesh size, the lower amount of conger eel catch and number of bycatch species, whereas the amount of bycatch showed increasing trend.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.48 no.4
• /
• pp.387-400
• /
• 2012

Species composition and seasonal variation of aquatic organism in the coastal waters off Taean, Korea were investigated using catches by commercial fishing of the pot and gill net from April 2010 to January 2011. A total of 58 species, 10,602 individuals and 547,569g of aquatic organism were collected during the study. Aquatic organism were composed of 22 species of Pisces, 20 species of Crustacea, 8 species of Gastropoda, 3 species of Echinodea, 2 species of Cephalopoda and Bivalvia, and 1 species of Holothuroidea. 41 species in 9 orders and 22 families were collected by the pot, and 28 species in 15 orders and 22 families were collected by the gill net. Volutharpa ampullacea was the most dominant in the pot, while Okamejei kenojei was the most dominant in the gill net. These two species accounted for 73.9% in the number of individuals, and 64.4% in biomass. The number of species was high in spring in the pot, and autumn in the gill net. The number of individuals and biomass were highest in winter and summer respectively in the pot, and summer in the gill net. The number of species of the consignment quantity caught by commercial fishery of the pot and gill net in Mohang was 12 and 14 respectively. Cluster analysis based on species composition of the 18 most common species showed that the species were separated into 3 different group. Group A was composed of species which were abundant in spring, group B was composed of species which were abundant in summer and autumn, and group C was composed of year-round residents.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.41 no.1
• /
• pp.27-34
• /
• 2005

This study was conducted to examine the mesh selecivity and optimum mesh size of spring frame trap for conger eel. Conger myriaster. It was carried out on 25th Sep. 2002 at the coastal sea of Nung-po, Geojedo. The experimental fishing gear was used in five kinds of different mesh size spring frame trap that were 15mm, 20mm, 25mm, 30mm and 35mm, and one plastic pot as control fishing gear that was 6.7mm hole diameter. The mesh size 15mm, 20mm are the current gears, 25mm, 30mm are used in experiment, and 35mm is the legal mesh. These were made 50 traps, respectively. The mesh selectivity curve was analysed by the Kitahara's method(1968) and the optimum mesh size was estimated by relationship between the total length and diameter of conger eel and by the mesh selectivity master curve. The results obtained are summarized follows : 1. The total number of catch by the trap for conger eel was 835, it was consisted of 537 conger eel(64.4), 225 crabs(2639%) and 73 others(8.7%). 2. The value of maximum 1/m on the mesh selectivity curve was estimated at about 23.9. 3. The optimum mesh size of spring frame trap for conger eel was estimated 34.0mm in 50% selection range of the mesh selectivity master curve.