• Title/Summary/Keyword: beam trawl

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Species composition and community structure of fish by shrimp beam trawl between Sacheon Bay and coastal waters off Namhae, Korea (사천만과 남해연안에서 새우조망에 어획된 어류의 종조성 및 군집구조)

  • SONG, Se Hyun;JEONG, Jae Mook;LEE, Seung Hwan;KIM, Do Hoon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.55 no.3
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    • pp.217-232
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    • 2019
  • It was turned out by shrimp beam trawl monthly survey from March, 2015 to February, 2016 that different species composition and abundance of the fish assemblages in Sacheon Bay and coastal waters off Namhae, Korea were compared. As a result of monthly measured sea temperature and salinity of Sacheon Bay and coastal waters off Namhae, sea temperature of both areas was changed seasonally; however, differences in sea temperature occurred during certain periods depending on the region. Salinity was generally low in Sacheon Bay affected by fresh water, and both areas was low in summer and high in winter. A total of 73 species representing 37 families were collected in Sacheon Bay. The dominant fish species in terms of numbers and biomass were Liparis tanakae, $23,077inds./km^2$, $332.1kg/km^2$. A total of 91 fish species representing 49 families were collected in coastal waters off Namhae. The dominant fish species in terms of numbers were Leiognathus nuchalis, $139,683inds./km^2$ and biomass were Chelidonichthys spinosus, $1,078.6kg/km^2$. Analysis of dendrogram of the clustering showed that Sacheon Bay and coastal waters off Namhae were distinctive featured (global R = 0.691, p = 0.017). And except of summer season (July-October), there was a distinctive feature seasonally (global R = 0.844, p = 0.001). The fish species that appeared in common in both areas, where fish species caught in Sacheon Bay, an important inner bay,were smaller than those caught in coastal waters off Namhae appeared. It presented that Sacheon Bay plays a more important role in spawning and nursery ground for fisheries resource than coastal waters off Namhae, Korea.

Classification of Fishing Gear (어구의 분류)

  • 김대안
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.32 no.1
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    • pp.33-41
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    • 1996
  • In order to obtain the most favourable classification system for fishing gears, the problems in the existing systems were investigated and a new system in which the fishing method was adopted as the criterion of classification and the kinds of fishing gears were obtained by exchanging the word method into gear in the fishing methods classified newly for eliminating the problems was established. The new system to which the actual gears are arranged is as follows ; (1)Harvesting gear \circled1Plucking gears : Clamp, Tong, Wrench, etc. \circled2Sweeping gears : Push net, Coral sweep net, etc. \circled3Dredging gears : Hand dredge net, Boat dredge net, etc. (2)Sticking gears \circled1Shot sticking gears : Spear, Sharp plummet, Harpoon, etc. \circled2Pulled sticking gears : Gaff, Comb, Rake, Hook harrow, Jerking hook, etc. \circled3Left sticking gears : Rip - hook set line. (3)Angling gears \circled1Jerky angling gears (a)Single - jerky angling gears : Hand line, Pole line, etc. (b)Multiple - jerky angling gears : squid hook. \circled2Idly angling gears (a)Set angling gears : Set long line. (b)Drifted angling gears : Drift long line, Drift vertical line, etc. \circled3Dragged angling gears : Troll line. (4)Shelter gears : Eel tube, Webfoot - octopus pot, Octopus pot, etc. (5)Attracting gears : Fishing basket. (6)Cutoff gears : Wall, Screen net, Window net, etc. (7)Guiding gears \circled1Horizontally guiding gears : Triangular set net, Elliptic set net, Rectangular set net, Fish weir, etc. \circled2Vertically guiding gears : Pound net. \circled3Deeply guiding gears : Funnel net. (8)Receiving gears \circled1Jumping - fish receiving gears : Fish - receiving scoop net, Fish - receiving raft, etc. \circled2Drifting - fish receiving gears (a)Set drifting - fish receiving gears : Bamboo screen, Pillar stow net, Long stow net, etc. (b)Movable drifting - fish receiving gears : Stow net. (9)Bagging gears \circled1Drag - bagging gears (a)Bottom - drag bagging gears : Bottom otter trawl, Bottom beam trawl, Bottom pair trawl, etc. (b)Midwater - drag gagging gears : Midwater otter trawl, Midwater pair trawl, etc. (c)Surface - drag gagging gears : Anchovy drag net. \circled2Seine - bagging gears (a)Beach - seine bagging gears : Skimming scoop net, Beach seine, etc. (b)Boat - seine bagging gears : Boat seine, Danish seine, etc. \circled3Drive - bagging gears : Drive - in dustpan net, Inner drive - in net, etc. (10)Surrounding gears \circled1Incomplete surrounding gears : Lampara net, Ring net, etc. \circled2Complete surrounding gears : Purse seine, Round haul net, etc. (11)Covering gears \circled1Drop - type covering gears : Wooden cover, Lantern net, etc. \circled2Spread - type covering gears : Cast net. (12)Lifting gears \circled1Wait - lifting gears : Scoop net, Scrape net, etc. \circled2Gatherable lifting gears : Saury lift net, Anchovy lift net, etc. (13)Adherent gears \circled1Gilling gears (a)Set gilling gears : Bottom gill net, Floating gill net. (b)Drifted gilling gears : Drift gill net. (c)Encircled gilling gears : Encircled gill net. (d)Seine - gilling gears : Seining gill net. (e)Dragged gilling gears : Dragged gill net. \circled2Tangling gears (a)Set tangling gears : Double trammel net, Triple trammel net, etc. (b)Encircled tangling gears : Encircled tangle net. (c)Dragged tangling gears : Dragged tangle net. \circled3Restrainting gears (a)Drifted restrainting gears : Pocket net(Gen - type net). (b)Dragged restrainting gears : Dragged pocket net. (14)Sucking gears : Fish pumps.

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A selective effect of grid and window net in the shrimp beam trawl fishery (새우조망 어업에서 그리드와 윈도우 네트의 선택효과)

  • JANG, Choong-Sik;CHO, Youn-Hyoung;AN, Young-Su
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.51 no.3
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    • pp.375-386
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    • 2015
  • The study aims at a selective effect of the Grid and Window net in the shrimp beam trawl. The experimental trawling of the Proto type, Grid type and Grid and Window net type was performed in a sea area of Geo-je and Tong-yeong from Mar, 2006 to Apr, 2010. The obtained results are as follows; Catch per unit area (Number) of the Proto type net and Grid type net were $0.18/m^2$, $0.23/m^2$, respectively. The Grid type demonstrated 2.4% lower bycatch rate than the proto type (6.6% vs 4.2%, respectively). In addition, in terms of total weight, the bycatch rate of Grid type was 7.6% lower than the proto type (50.2% vs 42.6%, respectively). In the comparison of shrimp catch, the Proto type demonstrated better haul outcome ($0.02case/m^2$) than the Grid & Window type ($0.02case/m^2$). The Grid & Window net type demonstrated 16.4% lower bycatch rate than the Proto type (32.2% vs 48.6%, respectively). In addition, in terms of total weight, the bycatch rate of Grid & Window net type was 8.3% lower than the Proto type (85.9% vs 94.2% respectively).

Estimation of Early Growth and Spawning Period of Marbled Flounder (Pseudopleuronectes yokohamae) in the Water off Namhae of Korea as Indicated from Daily Growth Increments in Otoliths (문치가자미(Pseudopleuronectes yokohamae) 치어의 이석 일륜을 이용한 성장 및 산란시기 추정)

  • Joo, Hyeong-Woon;Gwak, Woo-Seok
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.19 no.1
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    • pp.35-40
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    • 2014
  • Hatching date, main spawning period and growth of juvenile marbled flounder (Pseudopleuronectes yokohamae) were determined by analysis of microstructure in otoliths. Marbled flounders were collected by a small beam trawl in Namhae from February 2011 to January 2012. The length (L, mm) was related to body weight (W, g); $W=9.76^*10^{-8}L^{4.39}$ ($r^2=0.93$). The length was also related to otolith radius (R, ${\mu}m$); L=0.0795R+0.2249 ($r^2=0.92$). The growth in length was represented by Gompertz growth curve; $L_t=135{\exp}\{-{\exp}[0.0103(t-116)]\}$ ($r^2=0.83$). The hatching date calculated from the number of daily growth increments in otoliths was between mid-December and mid-February.

Seasonal variation of fisheries resources composition in the coastal ecosystem of the middle Yellow Sea of Korea (서해 중부 연안생태계 수산자원의 종조성과 계절변동)

  • Lee, Jae-Bong;Lee, Jong-Hee;Shin, Young-Jae;Zhang, Chang-Ik;Cha, Hyung-Kee
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.46 no.2
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    • pp.126-138
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    • 2010
  • To investigate seasonal variation of fisheries resources composition and their correlationships with environmental factors in the coastal ecosystem of the middle Yellow Sea of Korea, shrimp beam trawl were carried out for the fisheries survey. Fisheries resources of 81 species, 57 families, and 6 taxa totally were collected by shrimp beam trawl in the middle coastal ecosystem of Yellow Sea of Korea. Species were included 6 species in Bivalvia, 6 in Cephalopoda, 22 in Crustacea, 2 in Echinodermata, 5 in Gastropoda, and 40 in Pisces. Diversity indices (Shannon index, H') showed seasonal variation with low value of 2.14 in winter, and high value of 2.67 in spring. Main dominant species were Oratosquilla oratoria, Octopus ocellatus, Acanthogobius lactipes, Cynoglossus joyneri, Rapana venosa venosa, Loligo beka, Chaeturichthys stigmatias, Raja kenojei, Microstomus achne and Paralichthys olivaceus, that were occupied over 58% of total individuals, and 55% of wet weight. Fisheries organism made four coordinative seasonal groups by the principal component analysis (PCA), showing stronger seasonal variation than spatial variation. PC from PCA showed statistically significant cross-correlationships with seawater temperature, $NH_4$-N, TP and chlorophyll a (P < 0.05).

On the motion characteristics of small trawler in trawling job and sailing (소형 트롤 어선의 예망과 항해중의 동요특성)

  • Kang, Il-Kwon;Kim, Hyung-Seok;Kim, Jung-Chang;Kim, Min-Seok;Jo, Hyo-Jae;Lee, Chun-Ki
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.40 no.4
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    • pp.311-318
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    • 2004
  • It is very important for the safe navigation and fishing operation to ensure the hull response of a fishing vessel in rough seas. This is an experimental study on the dynamical characteristics of ship's motion during operating job and sailing in the real sea. The experiments were carried out on the small stern trawler in operating job and sailing, and then the ship's roll and pitch motion were simultaneously recorded by P/C according to the wave directions. From these data, the statistical properties and power spectra were obtained and the analysis of ship's motions in the both case were made. The results obtained are summarized follows : (1) The amplitudes of pitch motion don't appear a big different between trawl job and sailing, but at bow seas, its in sailing have a tendency to increase more than in trawl job. The amplitudes of roll motion appear a bog different between trawl job and sailing, but at beam sea, that slightly decreasing tendency. (2) The peak period of pitch motion in trawl job and sailing change, but that of roll motion don't change according to the direction of waves. (3) The warp tention cause the motion of hull to be reduce, if the tention of each side have a ballance.

Seasonal Variation in Shrimp Communities in the Southern Coast of Korea (한국 남해안 새우류 군집의 계절변이)

  • Kim, Jong-Bin;Cnoi, Jung-Hwa
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.40 no.1
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    • pp.53-57
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    • 2007
  • We examined seasonal variation In the abundance and species composition of shrimp communities in Doam Bay and around Naro-do, Korea. Samples were collected monthly from March 2001 to February 2002 (Doam Bay) and from December 2000 to November 2001 (Naro-do) usinga beam trawl. A total of 19 shrimp species representing eight families were collected from Doam Bay. The dominant species were Exopalaemon carinicauda, Trachysalambria curvirostris, Parapenaeopsis tenella and Crangon hakodatei, which accounted for 92.6% of individuals and 92.8% of biomass. In the Naro-do area, a total of 18 shrimp species representing eight families were collected. The dominant species were C. hakodatei and P. tenella, which accounted for 78.6% of individuals. Exopalaemon carinicauda, T. curvirostris, P. tenella, C. hakodatei and Metapenaeus joyneri accounted for 89.6% of biomass. In each season, the pattern of species appearances differed in the two areas.

New Occurrences of Two Penaeid Species (Crustacea: Decapoda: Dendrobranchiata) in Korean Waters

  • Kim, Jung Nyun;Choi, Jung Hwa;Lee, Jeong-Hoon;Kim, Joo Il
    • Fisheries and Aquatic Sciences
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    • v.16 no.4
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    • pp.325-329
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    • 2013
  • New occurrences in Korean waters were recorded for two penaeid species: Atypopenaeus stenodactylus (Stimpson, 1860) and Metapenaeopsis toloensis Hall, 1962, which were previously known from the Indo-West Pacific up to southern Japan. The specimens were collected from the southeastern coast of Korea by a shrimp beam trawl. The former is the only known member of the genus Atypopenaeus and the latter is the sixth species of the genus Metapenaeopsis reported in Korea. Morphological descriptions and illustrations with color photographs of the specimens are given. At present, the Korean Penaeidae consist of 20 species in 11 genera. A key to the Korean genera of family Penaeidae is also presented.

Possibility of Fishery in Offshore Wind Farms (해상풍력발전단지 내 어업 가능성에 관한 고찰)

  • Jung, Cho-Young;Hwang, Bo-Kyu;Kim, Sung-Cheol
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.5
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    • pp.535-541
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    • 2019
  • The purpose of this study was to investigate the possibility of fishery in offshore wind farms and evaluate the risk linked to the presence of turbines and submarine cables in these areas. With this objective, we studied an offshore wind farm in the Southwest Sea and the current state of vessels in the surrounding National Fishing Port. The risk assessment criteria for 22 fishing gears and methods were set by referring to the fishing boats; thereafter, the risk was assessed by experts. The fishing gears and methods that could be safely operated (i.e., associated with low risk) in the offshore wind farm were: single-line fishing, jigging, and the anchovy lift net. The risk was normal so that it is possible to operate, but the fishing gears and methods that need attention are: the set long line, drifting long line, troll line, squid rip hook, octopus pot, webfoot octopus pot, coastal fish pot, stow net on stake, winged stow net, stationary gill net, and drift gill net. Moreover, the fishing gears and methods difficult to operate in the of shore wind farm (i.e., associated with high risk) were: the dredge, beam trawl, and purse seine. Finally, those associated with very high risk and that should not be allowed in offshore wind farms were: the stow net, anchovy drag net, otter trawl, Danish seine, and bottom pair trawl.

Seasonal Variation in Species Composition of Fish with Depth in Asan Bay (아산만 천해역 수심에 따른 어류 종 조성의 계절 변동)

  • Hwang, Hak-Bin;Lee, Tae-Won
    • Korean Journal of Ichthyology
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    • v.11 no.1
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    • pp.52-61
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    • 1999
  • Seasonal variation in species composition of fish with depth was determined by analysis of bimonthly samples collected by a beach seine at the shallow water (St. 1 < 1.5m) and by beam trawl at the two stations (St. 2, 5~7m and St. 3 > 15 m) from October 1997 to August 1998 off Ippa-do in Asan Bay. Of forty species identified, 13 species at St. 1,28 species at the St. 2 and 30 species at the St. 3 were collected. The fish density was also increased with depth. Favonigobius gymnauchen occupied 55.7% at St. 1 and 38.9% of the number of individuals at St. 2. Almost of fish collected at these two stations were juveniles, and they were principally collected in August and in November. At St. 3, relatively large fishes were collected. Among them Pholis fangi and Chaeturichthys stigmatias predominated in the number of individuals. Abundance was low, but a large number of species were collected in winter. Principal component analysis revealed that the species composition at the shallower stations was different from that at the deeper station. The number of species and abundance of fish in Asan Bay was lower than in the other western coastal waters of Korea. Species composition in the study area of sandy bottom was different from that in the inner Asan Bay of mud bottom.

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