• Title/Summary/Keyword: Catch variation

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Seasonal Variation of Fish Catch Using a Fence Net in the Shallow Tidal Flat off Ganghwado, Korea (강화도 갯벌 천해의 건간망 어획 어류의 계절 변동)

  • HWANG Sun Wan;KIM Chong Kwan;LEE Tae Won
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.36 no.6
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    • pp.676-685
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    • 2003
  • Seasonal variation of the fishery resource in the shallow waters of Ganghwado tidal flat was investigated using monthly collected samples with a fence net from June 1998 to May 1999. Thirty-six species were found including 27 fish species, 6 crustaceans, and 3 molluscs. Of the fish, Konosirus punctatus, Sardinella zunasi Liza haematocheila and Synechogobius hasta dominated in the number of individuals $(92.1\%)$ and in biomass $(94.5\%).$ A few number of resident species, such as L. haematocheila and S. hasta, were collected only during the cold months. As the water temperature increased in the spring, the adult migratory fish such as K. punctatus and S. zunasi, were collected. In the summer, the juvenile fish recruited in the shallow water showing a peak in fish abundance. The data suggested that they grew until late autumn before moving to deeper waters for over-wintering. The principal component analysis showed that the seasonal variation in species composition was principally determined by water temperature and/or water temperature related factors. The species composition of the fish assemblage in the study area suggested that these species are highly adapted to extreme seasonal temperature variation and high water turbidity.

The Sliding Window Gene-Shaving Algorithm for Microarray Data Analysis

  • 이혜선;최대우;전치혁
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2002.06a
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    • pp.139-152
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    • 2002
  • Gene-shaving(Hastie et al, 2000) is a very useful method to identify a meaningful group of genes when the variation of expression is large. By shaving off the low-correlated genes with the leading principal component, the primary genes with the coherent expression pattern can be identified. Gene-shaving method works well If expression levels are varied enough, but it may not catch the meaningful cluster in low expression level or different expression time even with coherent patterns. The sliding window gene-shaving method which is to apply gene-shaving in each sliding window after hierarchical clustering is to compensate losing a meaningful set of genes whose variation is not large but distinct. The performance to identify expression patterns is compared for the simulated profile data by the different variance and expression level.

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A Variation of Fishes Catched by the Bottom Trawl in the Boundary Zone between Busan and Tsushima (부산-대마도 경계수역에서 저층트롤 어획물의 변동)

  • Kim, Min-Seok;Kim, Dong-Su;Kim, Min-Son;Lee, Jong-Gun
    • Journal of Fisheries and Marine Sciences Education
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    • v.22 no.3
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    • pp.341-353
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    • 2010
  • Authors investigated the species composition of fishes for about 13months in the boundary sea water between Busan and Tsushima. We caught 81 species, 1,603 individuals and 437.7kg in biomass. The first dominant species by seasons were common squid, angler, angler and Psenopsis anomala respectively. Angler was also the first dominant species in biomass for four seasons. Catch per unit effort (kg/hr) was the highest in winter and the lowest in summer. But there was a little difference in accordance with station compared with season. There was big difference by season in the diversity index, the evenness index and the dominant index. But there was little difference between above indexes. The total length of common squid was the tallest in autumn and winter, that of blackthroat seaperch was the tallest in autumn and the lowest in winter. But angler's total length was almost same all through the year.

Seasonal Species Composition and Fluctuation of Fishes by Beam Trawl in Yeoja Bay (빔트롤을 이용한 여자만 어류의 계절별 종조성과 변동)

  • Lee, Sun-Kil;Seo, Young-Il;Kim, Joo-Il;Kim, Hee-Yong;Choi, Mun-Sung
    • Korean Journal of Ichthyology
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    • v.23 no.3
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    • pp.206-216
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    • 2011
  • To investigate seasonal and yearly variation of fishes composition in Yeoja Bay of Korea, fisheries survey were carried out using beam trawl from 2006 to 2009. A total of 44 fish species were collected. The major dominant species were Pennahia argentatus, Thryssa adelae, Thryssa kammalensis and Cynoglossus joyneri, which were occupied over 63% total individuals, and 50% of wet weight. The diversity index (H') was about 1.62 (1.46~1.77) by seasons, and seasons of similarity by fishes were divided into two groups, which were March with December and June with September. ANOVA test showed that there were not significant difference between individuals and catch weight (kg) per unit area (km$^2$) by year and season, except for catch weight per unit area by season.

Lessons from Korean Innovation Model for ASEAN Countries Towards a Knowledge Economy

  • Ocon, Joey D.;Phihusut, Doungkamon;del Rosario, Julie Anne D.;Tuan, Trinh Ngoc;Lee, Jaeyoung
    • STI Policy Review
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    • v.4 no.2
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    • pp.19-40
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    • 2013
  • The Association of Southeast Asian Nations (ASEAN) achieved relatively rapid economic growth over the past decade. Sustainable growth among member states, however, is put into question due to macroeconomic challenges, political risk, and vulnerability to external shocks. Developed countries, in contrast, have turned into less labor-intensive technologies to further expand their economies. In this paper, we review the science, technology, and innovation (STI) policies and statuses of the scientific and technological capabilities of the ASEAN member countries. Empirical results based on STI indicators (R&D spending, publications, patents, and knowledge economy indices) reveal considerable variation between the science and technology (S&T) competence and effectiveness of STI policies of ASEAN members. We have categorized nations into clusters according their situations in their S&T productivity. Under the Korean Innovation Model, Cambodia, Laos, Myanmar, and Brunei are classified as being in the institutional-building stage, while Malaysia, Thailand, Indonesia, the Philippines, and Vietnam in the catch up stage, and Singapore in the post-catch up stage. Finally, policy prescriptions on how to enhance the S&T capabilities of the developing ASEAN countries, based on the South Korea development experience, are presented.

The Relationship between Coastal Cold Water and Catch Conditions of Common Squid(Todarodes Pacificus STEENSTRUP) in the East Sea of Korea in Summer (여름철 동해안 연안 냉수와 오징어 어황과의 관계)

  • Park, Jong-Hwa;Park, Kwang-Ho;Lee, Ju-Hee
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.34 no.2
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    • pp.105-116
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    • 1998
  • This paper, examines the relationship between water temperatures and fishing conditions of common squid by the squid angling fishery from June to September in 1993-1995. The condition of the common squid fishing largely depended on the fluctuation of water temperature in the coastal area of Gampo. Monthly mean water temperatures during June m September in 1993 and 1994 were relatively higher than those in 1995 in Gampo area. But the values between July and August in 1995 were about 5$^{\circ}C$ lower than those in 1993 and 1995. Coefficients of variation (CV) of water temperature showed the lowest value during July ~ September in 1993, however, the highest value was observed in July and August in 1994. Catch per unit effort (CPUE ; kg/angling) showed a peak with 73.7kg in 1993 when the CV was low. On the other hand, the lowest CPUE of 39.6kg was observed in 1994 when the CV was high. It was concluded that the high stability of water temperatures and the weak strength of cold water have caused the good fishing conditions of common squid.

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The Relationship between Oceanographic Condition and Fishing Ground Distribution of Yellow Croaker in the East China Sea and the Yellow Sea (동지나해, 황해의 참조기 어장분포와 해황과의 관계)

  • YANG Seong-Ki;CHO Kyu-Dae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.15 no.1
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    • pp.26-34
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    • 1982
  • The East China Sea and the Yellow Sea are abundant in nutritions because of river inflows and are important as the nursery and spawning grounds of demersal and pelagic fishes. The remarkable thermal front between the Yellow Sea Bottom Cold Water and the Tsushima Warm Current is formed in this region, and the fluctuation of this front may affect the variation of the yellow croaker fishing ground. To investigate the mechanism of the yellow croaker fishing ground, the distribution ana seasonal change of the fishing ground are examined by using catch of stow net fishery (Fisheries Research and Development Agency, 1970-1979) and the water temperature data (Japan Hydrographic Association, 1978). The main fishing ground of yellow croaker was nine sea areas (rectangle of 30' latitude by 30' longitude) located at 40-150 nautical miles west and southwest of Jeju Island, the area of which occupies no more than $11\%$ of all fishing grounds, and it appeared that about $70\%$ of total catch of ten years was concentrated in this area. The main fishing periods were from March to May and September to October. The coefficients of variation of the catch for the main fishing ground were from 0.8 to 2.1 and the condition of all fishing grounds was generally unstable. The mean CPUE was 27kg/haul at the main fishing ground, while it was the largest on boundary area of the Yellow Sea Bottom Cold Water. It was found that the seasonal movement of fishing ground is related to the expansion and reduction of the Yellow Sea Bottom Cold Water ($10^{\circ}C$).

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Prediction of the Variation in Annual Biomass of White Croaker Argyosomus argentatus in Korean Waters using Leslie Matrix (한국 연근해 보구치, Argyrosomus argentatus의 Leslie Matrix에 의한 자원변동 예측)

  • LEE Sung Il;ZHANG Chang Ik
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.34 no.5
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    • pp.423-429
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    • 2001
  • Prediction of the variation in annual biomass was conducted for the white croaker. Argyrosomus argentatus in Korean waters using leslie Matrix, based upon fishery data for the past 21 years and biological data, We used density-independent and density-dependent Leslie Matrix models. Similar parameters were estimated from two models except that the density-dependent model was influenced by the density effect variable, q(i,t), The eigenvalue of the white croaker population for the $1984\~1995$ period was estimated to be 0.8, indicating a declining pattern of the population. The survival rate of 0-th year class was calculated to be 0.00005. Based on the schedule of the age-specific survival rate and fecundity, the future biomass and catch was predicted for various levels of fishing mortalities (F), If F was set at 0.252/yr ($F_{35x}$) or 0.368/yr ($F_{0.1}$), the biomass and catch increased, and if F was set at 0.922 ($F_{current}$), the biomass and catch decreased, The fishing mortality at equilibrium was estimated to be 0.7/yr. Finally, the management strategy of the white croaker was discussed.

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Seasonal Variation of Fish Assemblages on Jangbong Tidal Flat, Incheon, Korea (장봉도 갯벌을 이용하는 어류군집의 계절 변화)

  • Seo, In-Soo;Hong, Jae-Sang
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.43 no.5
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    • pp.510-520
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    • 2010
  • This study investigated the community structure and seasonal variation of the fish assemblages on Jangbong tidal flat, Incheon, Korea. Fish were collected monthly using a small otter trawl from November 1999 to January 2001. Thirty-six fish species were recorded, with a mean density of 185 individuals and biomass of 2,594.3 gWWt. The most abundant species by number were Johnius grypotus (23.7%), Acanthogobius hasta (17.8%), and Cynoglossus joyneri (10.7%), while the dominant species by catch weight were Acanthogobius hasta (21.2%), Sebastes schlegeli (16.2%), J. grypotus (14.0%), and C. joyneri (10.8%). Cluster analysis and non-metric multi-dimensional scaling (nMDS) were applied to assess the seasonal fluctuation in the fish assemblages. Based on the result of the cluster analysis and nMDS ordination, the faunal group could be divided into cold- and warm-water specialist groups. The cold-water specialists included A. hasta, Acanthogobius luridus, Triaenopogon barbatus, Tridentiger trigonocephalus, and Liza haematocheila. The warm-water specialists were J. grypotus, C. joyneri, S. schlegeli, and Hexagrammos otakii. In conclusion, the community structure showed a distinct seasonal trend, which seemed to be related to the seasonal fluctuations in water temperature.

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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