• Title, Summary, Keyword: Catch fluctuation

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Fishing status of jack mackerel fishery in the southeastern Pacific Ocean (남동태평양의 전갱이트롤어업 현황)

  • Kim, Doo-Nam;Lee, Dong-Woo;Oh, Taeg-Yun;Choi, Young-Min
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.46 no.4
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    • pp.430-440
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    • 2010
  • To investigate the catches of jack mackerel fishery, a series of fishing experiments was conducted in the high seas of the southeastern Pacific Ocean ($30^{\circ}S-38^{\circ}S,\;82^{\circ}W-95^{\circ}W$) during the period of 9 August to 18 December, 2003 by commercial fishing vessel and research vessel. The number of 205 tows fishing was carried out in the southeastern Pacific Ocean. The total catch was 1,988 ton and CPUE was 2.4 ton/hour. CPUE showed high values in the frontal zone during the survey. Main target species caught from the experimental fishing were the jack mackerel, Trachurus murphyi (98.1%) and chub mackerel, Scomber japonicus (1.9%) as bycatch. Body length of the jack mackerel was different between female and male. The high mean catch per unit effort of jack mackerel was showed when the fishing ground of jack mackerel fishery was over the $110^{\circ}W$ in the southeastern Pacific Ocean. But the fluctuation of the catch per unit effort in the western part of fishing ground was not matched with those year. Reliable physical and oceanographical information will be useful for the efficiency of fishing activity. According to the result of monthly movement of center of fishing ground, the fishing activity of jack mackerel fishery was performed northward in the southeastern Pacific Ocean as time passes.

Abundance of Argentine shortfin squid, Illex argentinus(Castellanos) in Relation to Fluctuation of Water Temperature in the Southwestern Atlantic Ocean (수온변동에 따른 아르헨티나 짧은지느러미오징어, Illex argentinus의 풍도 변화)

  • Kim, Yeong-Seung;Kim, Doo-Nam
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.40 no.4
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    • pp.282-294
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    • 2004
  • Catches of Argentine shortfin squid Illex argentinus showed a sharp decrease, reaching 99,000ton in 1993 and 56,700ton in 1994, and then increased again reaching 130,300ton in 1997 from 78,600 ton in 1996. The Korean squid jigging fishery around Falkland for Illex argentinus commences usually its operation in January and lasts August and peak in catch was showed from March to May. To elucidate possible environmental effects on their abundance during the main fishing season in 1993-1994 and 1996-1997, sea surface temperatures were used as an indicator of the position and strength of the oceanographic structures in the Southwestern Atlantic Ocean. The high catch and catch per unit effort of Illex argentinus was showed when the Faliland Current was not affected in the fishing area in 1993 and 1997. But they were sharply decreased from the middle of April 1994 and the late of April 1996 when the Faliland Current directly affects the fishing ground.

Yearly Fluctuation in the Fish Species Composition of Shrimp Beam Trawls off Maemuldo, Korea, during 2007-2009 (2007-2009년 매물도에서 새우조망에 의한 어류 종조성의 연변동)

  • Park, Jung-Youn;Kang, Hyun-Sook;Kang, Jung-Ha;Kim, Jin-Koo;Ryu, Jung-Hwa;Kim, Dong-Sun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.46 no.5
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    • pp.619-625
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    • 2013
  • We investigated yearly fluctuation of the fish species composition of beam trawls off Maemuldo in the east southern sea of Korea, from March 2007 to November 2009. A total of 75 fish species were collected during the period. The number of fish species accumulated amounted to 54, 64 and 75 species in 2007, 2008 and 2009, respectively. The number of newly occurring species increased with time. The number of expected resident species in Maemuldo was estimated as 9 species including Conger myrister, Okamejei kenojei and Pholis nebulosa, each of which appeared more than 14 out of a total 27 times. Cluster analysis showed that the years 2007 and 2008 were closely clustered, while the year 2009 was distantly clustered with 2007 and 2008. This may be due to the high catch ratio of Clidoderma asperrimum in 2009 alone, when a low water temperature phenomenon was observed unlike the situation in 2007 and 2008.

The Characteristics of a Fishing Ground at Yeosu Bay - Pound Net Fishing Ground - (여수해만의 어장학적 특성 - 정치망 어장을 중심으로 -)

  • 김동수
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.25 no.2
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    • pp.44-53
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    • 1989
  • In order to grasp the characteristics of a fishing ground at yeosu bay, the fluctuation in condition of the coast and that in catch by pound nets in the coast were investigated respectively. The results obtained are summarized as follows: 1. The water temperature in spring and summer was higher at the coast side than off shore, but in autumn and winter took the reverse. 2. The salinity was higher in spring and winter than in summer and autumn. A lower salinity zone was found at the Dolsan Do coast and higher ones were made off shore. 3. A eddy current was found at the Dolsan Do coast and a thermocline were made at the depth of 30 to 40 m in summer. But in autumn and winter the water became homogeneous. 4. The annual catch by the pound net was highest in 1984 and then decreased gradually. The monthly catch was highest in June and then decreased gradually. 5. The catches seemed to increase with the sea water temperature and salinity, and great catch was shown in 21$^{\circ}C$ to 27$^{\circ}C$ and 33.80% to 34.00%. 6. The component rate of fishes was 28.4% in spanish mackerel, 17.9% in anchovy, 19.5% in horse mackerel, 21.0% in sardine, 7.2% in hairtail, and 1% in common mackerel. 7. The fishes appeared continuously on way of fishing operation were spanish mackerel, hairtail, Yellow talil, crab, etc. An anchovy and sardine were caught mainly from March to July or August, horese mackerel and common mackerel from May to November. but puffer, swell fish, saury and filefish were caught mainly from April to October. 8. The sum of catch was largest in June, at which the wind direction was NE to SSW, the speed below 3.2m/sec, the atmospheric pressure below 1008mb, and precipitation beyond 154mm.

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Relationships between Fishing Condition and Sea Surface Temperature for Skipjack(Euthynnus pelamis) Caught by Small Fishing Boats (소형어선에 의한 가다랑어 (Euthynnus pelamis)의 어황과 수온)

  • Jeong, Dong-Gun;Rho, Hong-Kil
    • Journal of Fisheries and Marine Sciences Education
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    • v.10 no.1
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    • pp.15-30
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    • 1998
  • The variation of the catches of Skipjack(Euthynnus pelamis) and the relationships between the SST and the fishing ground is examined using the catches data of skipjack obtained by Iwawada Fisheries Cooperative of Chiba Prefecture in Japan from 1982 to 1988. The annual mean catch for Skipjack was 151,375.1kg. the annual fluctuation of catch was that the catch in 1984 was increasing, but it was decreased less than 50% in 1985, and was repeated after being a little recovered in 1986, and it was recovered with the level of 1984 in 1988. The fluctuation of catch for Skipjack in every fishing term is that daily mean catch of the primary fishing term (January, February and March) is 894.6kg, but the middle fishing term(April and May) more than four times of the primary fishing term is 3,666.0kg, the last fishing term(June and July) was decreasing at 767.9kg and the fishing ground gradually becomes extinct. The annual mean SST in fishing ground was an extent of from $19.0^{\circ}C$ to $20.2^{\circ}C$, the mean SST of every year except 1983 was from $19.0^{\circ}C$ to $19.9^{\circ}C$. It is said that the optimum SST of Skipjack in Sotobo sea area is the degree of $19.0^{\circ}C$. Therfore, the thing which will guess the time and the location appeared the optimum SST is the very important factor to operate efficiently. About the extent of SST in fishing ground, it was from $17.0^{\circ}C$ to $19.0^{\circ}C$ on March, from $17.5^{\circ}C$ to $20.5^{\circ}C$ on April and from $17.5^{\circ}C$ to $23.5^{\circ}C$ on May, which the extent of SST was gradually larger and larger, on June from $21.0^{\circ}C$ to $23.5^{\circ}C$, fishing ground was formed only the degree of SST more than $21.0^{\circ}C$.

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The Distribution of Catch of Anchovy by the Gill Net Fishery and Oceanographic Condition (멸치 자망 어획양의 분포와 해황)

  • SOHN Tae-Jun;KIM Jin-Kun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.16 no.4
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    • pp.341-348
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    • 1983
  • The Relationship between the distribution of the fishing grounds of anchovy and the oceanographic conditions in the Korean Waters are investigated by using the data of the catch of anchovy by the gill net fishery (Fisheries Research and Development Agency, 1969-1982) and the oceanographic observation data (Fisheries Research and Development Agency, 1979). The main fishing ground of anchovy by the gill net fishery was five fishing areas located in the adjacent seas of Sockcho, Kuryong-po, Kijang, Keoje island and Chungmu, the area of which occupies no more than $20\%$ of all fishing grounds, and it appeared that about $80\%$ of mean catches of fourteen years was concentrated in this area. The main fishing periods were from April to June and October to November. The coefficient of variation of the catch for the main fishing ground were from 0.3 to 0.6 and the condition of all fishing ground was generally stable. The mean CPUE was 81.2 kg/set at the main fishing ground. The annual mean catch of anchovy by the gill net was the smallest in February and the largest in May through a year. It was found that the fluctuation is related to the expansion and reduction of the isothermal line of $10^{\circ}C$.

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A study on resource utilization and management of chub mackerel, Scomber japonicus consider to proximate composition (영양성분을 고려한 고등어, Scomber japonicus 자원 이용과 관리 방안)

  • OH, Taeg-Yun;SHIM, Kil-Bo;SEO, Young-Il;KWON, Dae-Hyun;KANG, Su-kyung;LIM, Chi-Won
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.52 no.2
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    • pp.130-140
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    • 2016
  • This study analyzed annual catch trend during 45 years and monthly catch of the least 10 years (2005~2014) for chub mackerel caught in the Korean coastal waters. To determine fishing status of chub mackerel, fork length measurements were conducted at least twice every week for 100 individuals randomly selected at the Busan Cooperative Fish Market from January of 2012 to December of 2014; and biological characteristics and proximate composition (moisture, protein, fat, ash) were analyzed by length class (I~IV) on a monthly basis from January to December of 2014. Monthly catch trend showed low level below 5,000 mt from February to July, whereas high level above 15,000 mt from October to December. For the period between 2012 and 2014, annual average catch proportion of juvenile were relatively high at 68.1%, 53.1% and 53.2% from January to April, before spawning season, while those were low at 21.5%, 20.7% and 29.12% from June to November. As for the change in the proximate composition per 100 g of muscle, protein and ash did not change much by seasons and length class, whereas fat and moisture contents showed large fluctuations and complementary relationship between the two factors. Regardless of length class, monthly average fat content, containing Omega-3, showed the lowest at 7.18 g in April and highest at 19.27 g in December, which exhibited 2.6 times difference from one another. Regardless of fishing seasons, fat content by length class were 19.06 g for the class I and 6.43 g for the class IV, which showed three times difference. Fat contents of the class I were high at 26.97 g and 27.19 g in November and December, while low at 8.37 g and 9.99 g in April and May. Especially, fat contents from January to May were 5.0 g, which was the lowest. Therefore, it is expected that consumer could indirectly contribute fisheries management through their understanding and wise consumption based on fishing status and fluctuation of proximate composition.

On the Fluctuation of Trawl Fishing Condition in the Atlantic Coast of Africa 1. On the fishing condition of cutle fish, squid and octopus. (대서양 아프리카 연안 트로올 어장의 어황변동에 관하여 1. 오징어, 살오징어, 문어 종의 어황)

  • 김진건
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.13 no.2
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    • pp.27-32
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    • 1977
  • The paper deals the fishing condition of the stern trawlers operated in the Atlantic coast of Africa. The datas are gathered from the Korean stern trawlers operated in the area from June, 1975 to May, 1976. The obtained results are summarized as follows: 1. The mean catch per haul are calculated as, cuttle fish 14.5kg, large size squid(more than :lOOg of body weight) 28.2kg, small size squid(less than 300g) 36.4kg, octopus 47.0kg. 2. Small size cuttle fish(less than5OOg of body weight) are caught much during after spring tide in July to September, yet, large size ClIttle fish(more than 500g) are caught much during neap tide in October to January. 3. Small size squid(less than 300g of body weight) are cBught much during after spring tide in October to December, yet, large size squid(more than 3OOg) are caught much during before spring tide in October to March. 4. Octopus are caught during neap tide in July to August.

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Characteristics of Catch Fluctuation and Distribution of Yellow tail, Seriola quinqueradiata, TEMMINCK et SCHLEGEL, in Korean Waters (한국 연근해 방어 어획량 변동 및 분포특성에 관한 연구)

  • 김준택;노홍길;김상현;고준철;안영화;최찬문
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.38 no.1
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    • pp.11-19
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    • 2002
  • We studied the characteristics of catch fluctuation and distribution of yellow tail resources in Korean Waters from 1991 to 2000. The obtained results are summarized as follow, The distribution of yellow tail resources in Korean Waters was showed by mooving north-ward groups from Spring to Autumn and south-ward groups from Autumn to Winter with they passed Winter and spawned from the south of Jeju Island and Tsushima current. Therefore, the fishing ground of yellow tail by handline fishing around Marado targets a school of yellow tails which migrate south-ward so as to winter and spawn.

A study on fluctuation of the fishing grounds of target fishes by the Korean large purse seine fishery (대형선망어업의 주요 목표종의 어장 변동)

  • Lee, Jong-Hee;Lee, Jae-Bong;Zhang, Chang-Ik;Kang, Su-Kyung;Choi, Young-Min;Lee, Dong-Woo
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.48 no.2
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    • pp.107-117
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    • 2012
  • Korean large purse seine fishery catches chub mackerel, sardine, jack mackerel, Spanish mackerel, etc. which are mainly pelagic fish species. The proportion of chub mackerel was 60% over in Korean large purse seine fishery. Sea surface temperature (SST) increased $0.0253^{\circ}C$ per year and total rising rate was $0.759^{\circ}C$ from 1980 to 2009 in the southern sea of Korea, where is mainly fishing grounds of Korean large purse seine. It was that p<0.01 level was statistically significant. It is northward movement that the center of fishing grounds of chub mackerel by Korean large purse seine fishery moved 4.57km/yr. It was rapidly northward movement about 7.1km/yr, 8.13km/yr to move Spanish mackerel and bluefin tuna fishing grounds. However, the fishing grounds of jack mackerel were moved further south in the 2000s than the 1980s. Catch of tunas and bluefin tuna consistently increased in Korean waters. There was a significantly positive correlation between SST and catch of bluefin tuna in the fishing grounds of Korean waters.