• Title, Summary, Keyword: CPUE

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The Analysis of Fishery Buy-back Programs of Offshore Fisheries Concerning Fishery Production (근해어선 감척사업의 생산량에 관한 효과분석)

  • PARK, Byung-Soo;LEE, Myeong-Kyu
    • Journal of Fisheries and Marine Sciences Education
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    • v.17 no.1
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    • pp.115-131
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    • 2005
  • The fishery buy-back programs were studied to analyze fishery production and CPUE. The results from this study during the concerned period can be derived as follows: 1. In total offshore fisheries, CPUE for each boat increased 8.7%, and 8 fishing categories were increased in CPUE for each boat. CPUE for tonnage increased 4.2% in total offshore fisheries field, and 7 fishing categories increased in CPUE for tonnage. In total offshore fisheries, CPUE for HP increased 6.8%, and 8 fishing categories increased in CPUE for HP. 2. The correlation coefficient of the number of fishing boats vs. production and that of the tonnage vs. production were 0.91. This means that there is a strong relation between them. The correlation coefficient of the number of fishing boats vs. CPUE for each boat and that of the tonnage vs. CPUE for tonnage were -0.73 and -0.88 respectively. This reveals that there is a relatively strong reverse relation between them.

Standardization of Catch per Unit Effort (CPUE) for Bigeye Tuna (Thunnus obesus) by the Korean Longline Fishery in the Pacific Ocean (한국 다랑어 연승어업에 의한 태평양해역 눈다랑어 자원의 단위노력당어획량 (CPUE)의 표준화)

  • Yoo, Joon-Taek;Hwang, Seon-Jae;An, Doo-Hae;Kim, Jong-Bin;Kim, Zang-Geun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.43 no.6
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    • pp.740-746
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    • 2010
  • This study standardized the catch per unit effort (CPUE) of bigeye tuna (Thunnus obesus) caught by the Korean longline fishery in the Pacific Ocean. The study used a general linear model (GLM) to standardize the CPUE using catch and effort data aggregated by year, month, and $5{\times}5$ degrees of latitude and longitude in the tropical Pacific Ocean from 1982 to 2008 (except for 1988 and 1989). Explanatory variables in the GLM analysis included year, month, subtropical area, and number of hooks between floats (HBF). The study area and HBF were subdivided into three subtropical areas and six classes, respectively. During the study period, the standardized CPUE was significantly related to the nominal CPUE. The standardized CPUE declined sharply, as compared to the nominal CPUE, after the mid 1990s. In particular, the decline in the standardized CPUE in all subtropical areas in the 2000s was clearer than that of the nominal CPUE.

Species composition and abundance of fishery resources collected by gill net, trap net, and longline near Oenarodo, Go-heung Peninsula, Korea (고흥 외나로도 연안에서 자망, 통발, 주낙에 어획된 어족생물의 종조성 및 어획량 변동)

  • YOON, Eun-A;HWANG, Doo-Jin;MIN, Eunbi;CHO, Nam-Kyung;HAN, Yeoung-Min
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.53 no.3
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    • pp.246-255
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    • 2017
  • The species composition and variation in abundance of fishery resources near Oenarodo, Go-heung Peninsula, Korea, were investigated by gill net, trap net, and longline in May, July, and October 2015 and 2016. During the study period, the total catch included 14 species in the gill net, 11 species in the trap net, and 4 species in the longline. The dominant species were Portunus trituberculatus and Raja pulchrain the gill net, Charybdis japonicaand and Octopus vulgarisin in the trap net, and Muraenesox cinereusin in the longline. The Catch Per Unit Effort (CPUE) per individual and per weight in the gill net were similar in May and July of 2015 and 2016. In October 2015, the CPUE per individual was 2.1 ind./h and the CPUE per weight was 505 g/h higher than the results in 2016, but there was no significant difference in the total CPUE between 2015 and 2016. In the trap net, the CPUE per weight was similar in both 2015 and 2016, but the CPUE per individual was 2.7 ind./h higher in October 2015 than in October 2016 and the total CPUE was not significantly different from 2015 to 2016. The CPUE per individual and weight in the longline were significantly higher in July and October 2015 than in the same months of 2016, but the total CPUE in 2015 and 2016 did not show a significant difference.

Standardization of Catch per Unit Effort (CPUE) for Yellow Croaker (Larimichthys polyactis) in the East China Sea (동중국해 참조기자원에 대한 단위노력당어획량(CPUE)의 표준화)

  • Lee, Dong-Woo;Lee, Jae-Bong;Kim, Yeong-Hye;Jung, Suk-Geun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.41 no.5
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    • pp.346-352
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    • 2008
  • Yellow croaker (Larimichthys polyactis) is a major target species of large pair trawl fishery in the East China Sea. To standardize catch per unit effort (CPUE) of yellow croaker for the large pair trawl fishery, generalized linear model (GLM) was applied to evaluate and eliminate the influence of the explanatory factors (year, month, horse power and gross tonnage of vessel) on daily catches per boat collected and compiled by National Fisheries Research and Development Institute (NFRDI) from 1990 to 2007 at the fishery auction places of Busan, Masan and Incheon in Korea. Results of GLM showed that all of the factors significantly influenced on CPUE, explaining 36% of the total deviance. The standardized CPUE indicated that the abundance of yellow croaker in 2000's was 1.7 times higher than the CPUE in 1990's.

Relationship between Squid (Todarodes pacificus) Catch by Sea Block and Marine Environment in the East Sea during 1980s and 1990s (1980-1990년대 동해에서 해구별 오징어(Todarodes pacificus) 어획량과 해양환경의 관계)

  • Kim, Yoon-Ha;Moon, Chang-Ho;Choi, Kwang-Ho;Lee, Chung-Il
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.16 no.3
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    • pp.259-268
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    • 2010
  • Data on squid catches by the Korean jig fishery in sea blocks ($30'{\times}30'$), water temperatures at depth(30m, 50m and 100m) and zooplankton biomass in the East Sea from 1980 to 1999 were analyzed to examine the mechanism of formation of the high density stock area. Japanese common squid (Todarodes pacificus) catch in the East Sea was low in 1980s, while the catch was high in 1990s. The five sea blocks (No. 76, 82, 83, 87, 88) of the southern part in the eastern coastal waters of Korea showed high levels of percentage of total catch (35.1%), whereas the four sea blocks (No. 65, 71, 72, 78) of the coastal waters of Uleung Island showed high levels of percentage of CPUE (61.2%) for 20 years. Squid catches showed monthly fluctuations according to the vertical distribution of optimum water temperature for fishing ($14^{\circ}C{\sim}19^{\circ}C$). High total catch and high CPUE area matched well with $10^{\circ}C$ isothermal lines at 100m depth indicating northern limiting of Tsushima Warm Current, and temporal and spatial change in $10^{\circ}C$ isothermal line caused the change in total catch and CPUE. Horizontal distribution of zooplankton biomass by sea block was not matched well with those of total catch and CPUE, however pattern of time-series change in total zooplankton biomass was similar to that in total squid catch.

CPUE standardization of Pacific bluefin tuna caught by Korean offshore large purse seine fishery (2003-2016) (우리나라 대형선망어업에서 어획된 태평양참다랑어의 CPUE 표준화(2003-2016))

  • LEE, Sung Il;KIM, Doo-Nam;LEE, Mi-Kyung;JO, Heon-Ju;KU, Jeong-Eun;KIM, Jung-Jin
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.54 no.2
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    • pp.116-123
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    • 2018
  • Pacific bluefin tuna (Thunnus orientalis) has been mostly caught by the Korean offshore large purse seine fishery in Korean waters. The annual catch of Pacific bluefin tuna caught by the offshore large purse seine fishery in Korean waters showed less than 1,000 mt until the 1990s except for 1997. The catch sharply increased to 2,401 mt in 2000 and recorded the highest of 2,601 mt in 2003, but the catch has generally decreased with a fluctuation thereafter. The main fishing ground of Pacific bluefin tuna of this fishery is formed around Jeju Island. However, it expanded to the Yellow Sea, the coastal of Busan, and the East Sea, which depends on the migration patterns of Pacific bluefin tuna by season. The CPUE standardization of Pacific bluefin tuna was conducted using Generalized Linear Model (GLM) to assess the proxy of the abundance index. The data used for the GLM were catch (weight), effort (number of hauls), catch ratio of Pacific bluefin tuna, moon phase by year, quarter and area. The standardized CPUE from 2004 to 2011, except for 2003 and 2010, showed a steady trend, and then increased until 2014. The CPUE in 2015 decreased, and in 2016 was higher than that in 2015. The result of GLM suggests that the effect of the catch ratio of Pacific bluefin tuna is the largest factor affecting the nominal CPUE.

Standardization of CPUE for bigeye(Thunnus obesus) and yellowfin(Thunnus albacares) tunas by the Korean longline fishery in the Indian Ocean (우리나라 다랑어연승어업에 의한 인도양해역 눈다랑어(Thunnus obesus) 및 황다랑어(Thunnus albacares)의 CPUE 표준화)

  • Kwon, You-Jung;An, Doo-Hae;Lee, Jae-Bong;Zhang, Chang-Ik;Moon, Dae-Yeon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.44 no.3
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    • pp.194-206
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    • 2008
  • This study standardized catch per unit effort(CPUE) of the Korean longline fishery, which has been used to assess the status of stock as an index of abundance, for bigeye and yellowfin tunas in the Indian Ocean. The Generalized Linear Model(GLM) was used to analyze the fishery data, which were catch in number and effort data collected each month from 1971 to 2007 by $5\;{\times}\;5$ degree of latitude and longitude. Explanatory variables for the GLM analysis were year, month, fishing area, number of hooks between floats(HBF), and environment factors. The HBF was divided into three classes while the area was divided into eight subareas. Although sea surface temperature(SST) and southern oscillation index(SOI) were considered as environmental factors, only SST was used to build a model based on statistical significance. Standardized CPUE for yellowfin tuna showed a declining trend, while nominal CPUE for the species showed an increasing trend.

Analysis on the national catch, CPUE and monthly fishing grounds of walleye pollock, Theragra chalcogramma by the trawl fishery in the high seas of the Bering Sea (베링공해 명태 트롤어업의 국가별 어획량, CPUE 및 월별 어장)

  • JO, Hyun-Su
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.52 no.2
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    • pp.141-148
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    • 2016
  • Annual and monthly pollock catches, CPUE and fishing grounds in the high seas of Bering Sea between 1984 and 1992 were analyzed for centroid distribution and bivariate ellipses of trawlers of South Korea, Japan, Poland and China. The catch amount differed by country as 56.1%, 21.7%, 20.4% and 1.8% were caught by Japan, Korea, Poland and China respectively. Japan recorded the highest mean CPUE at 5.7 ton/hour while it was 4.3 ton/hour for Poland, 3.9 ton/hour for Korea and 2.4 ton/hour for China. Cumulative catch varied by month, with the minimum of 137,000 ton in March and the maximum of 848,000 ton in December. Monthly mean of CPUE was the lowest in February (2.0 ton/hour) and the highest in November (6.3 ton/hour). The centroid distribution of monthly fishing ground was located at a southern spot ($56^{\circ}$ 05'N, $178^{\circ}$ 55'E) in January, and it moved anti-clockwise toward $56^{\circ}$ 37'N, $178^{\circ}$ 24'E in December. Fishing grounds were scattered more by the east-west direction than by the south-north direction. The fishing grounds were similar for Korean, Japanese and Polish trawlers, but Chinese trawlers that fished only from July to December showed distinctively different fishing grounds from the others.

Studies on the Mackerel Pures Seine Operating in the Sea Area of Cheju Island - 4 . The Characteristics of Catch and Ability in Purse Seine - (제주도 주변해역 고등어 건착망의 연구 - 4 . 어획량의 특성과 어구의 성능 -)

  • 박정식
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.27 no.4
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    • pp.247-254
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    • 1991
  • Mackerel purse seine fishery is one of the most important fisheries in Korea and its annual mean catch from 1982 to 1988 is 350 thousand tons. Between 1982 and 1988, the characteristics of catch at 5 sectors of the sea area was analyzed according to operating sea block and the catch by fishes based on the data obtained from daily report of fishing condition that had been made out by 48 Korean fishing boats engaged in the fishery of purse seine. In these 5 sectors of the sea area, catch per net hauling in the coastal area of Cheju Island is less than that in the other sectors. Accordingly, the shape of fishing gear during operation has been measured to analyzed the deformation of net shape caused by the bottom current. (The lunar calender is used in the paper) The results obtained are as follows; The average CPUE of purse seines is 31.6 tons and it is higher from October to April than that from May to September. In the 5 purse seine fishing grounds, the ratio of net haul in the coastal sea area of cheju Island is 42.4% and it is the highest level, but the CPUE is 25.7 tons which is relatively low level. Each CPUE in the sea areas is significant differences with 1% level. Index of seasonal variation of mackerel CPUE from May to October is lower than the standard value, whereas index from November to January is higher. The diameter of circle by net shooting becomes shorter to the minimum caused by the bottom current during loose set, becomes narrower and the efficiency of fish encirclement becomes lower. The shape of leadline by bottom current becomes long oval type along with current direction in the tight set, while it becomes long oval type in the direction of a right angle to the current direction and the enclosed area is reduced hurriedly, and the deformation of net is most serious in the loose set.

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Trawl Fishing of Alaska Pollack in the Northwestern Pacific (북서태평양 트로올 어장의 명태어항)

  • Sung, Byung-Oun;chang, sun-duck
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.11 no.1
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    • pp.15-20
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    • 1975
  • The catch per unit effort and the migration of Alaska pollack Theragra chalcogramma were deduced from the catch data of 1, 208 hauls of a stern trawler operated on and around the continental shelf east of the Kamchatka Peninsula and Kurile Islands from October 1974 to December 1975. Alaska pollack occupied more than ninety per cent of the total catch of approximately 17, 760 metric tons, while the cuttle and flat fishes occupied less than five percent. Beside those fishes, approximately 131 metric tons of Alaska pollack roe were produced during the voyage from February to April 1975. The mean catch per unit effort in each sub-area of fishing ground was approximately 15.5 metric tons and the peak of the CPUE occured in January and August. The CPUE in the continental shelf east of Kamchatka Peninsula ($50^{\circ}- 52^{\circ} N$ Lat) showed the maximum of 25-34 metric tons in August. The main fish school is thought to migrate southward speedily in August-September along the continental shelf from the Kamchatka Peninsula to the east of Kurile Islands. The CPUE on the continental shelf east of Kamchatka Peninsula was higher than that on the steeper continental slope. However, the CPUE on the steeper flank of the bank east of Paramushiru Island and Onekotan Island was remarkably higher than that on the relatively flat top of the bank. The small-sized fishes of less than thirty centimeter in fork length began to recruit in the fishing ground since August 1965.

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