• Title/Summary/Keyword: fish scale

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Changes in Marine Ecosystem according to Climate Change and Fishery (기후변화에 따른 해양생태계 변화와 어업)

  • Hong, Sun-Kee
    • Korean Journal of Ecology and Environment
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    • v.47 no.4
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    • pp.302-311
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    • 2014
  • Global climate change is significant issue in marine ecosystem and fishery market. According to rising of both seawater temperature and sea-level, global fishery environment and marine ecosystem are changing drastically. Moreover, over-exploitation in fishery areas is the most important issue in the marine ecosystem conservation. In analysis and statistics of global network, major fish populations are decreasing very fastly, but fish catch are increasing annually. It means balance between product and consume is not appropriate in the global market. China as emerging new fish consumer in the world is strongly developing fishery industry and technology. In this paper, I try to review a relationship between marine ecosystem and climate change in global scale according to references. I also suggested possibility of sustainable global fishery in changing marine ecosystem by analysis of some related reports of international global fishery.

Ichthyofaunistic Biogeography of the East Sea: Comparison between Benthic and Pelagic Zonalities

  • Kafanov, Alexander I.;Volvenko, Igor V.;Pitruk, Dmitry L.
    • Ocean and Polar Research
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    • v.23 no.1
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    • pp.35-49
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    • 2001
  • An ichthyofauna analysis of the East Sea using quantitative investigation procedures for latitudinal variations of the species richness and clustering of the species list is presented to illustrate the application of the adopted geographical scaling (less than 1:10,000,000) which provides a principal opportunity for common benthic and pelagic biogeographical zonation. The distribution of both pelagic and benthic marine fish biota at a scale of biosphere (or its major sections) was highly influenced by spatial nonuniformity of hydrological structure associated with the various water circulations and frontal zones. Following zoogeographical zonations were established for the East Sea: Osaka, East Korea, Primorye, North Primorye, Northern East Sea, Uetsu, Tsugaru, Soya and West Sakhalin.

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Fisheries Resources -A Brief Introduction of the Republic of Senegal

  • Mbengue, Modou
    • Journal of Marine Bioscience and Biotechnology
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    • v.3 no.1
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    • pp.38-41
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    • 2008
  • Fish is a major source of protein for the Senegalese population. Fishing plays a dominant role in the Government's policy towards generating employment. It currently generates about 100,000 direct jobs (fishermen) for nationals, of which more than 90% are in small-scale fishing. The fishing industry also contributes to Government revenue through different agreements. In addition to associated dues, fishing agreements imply a series of economic, trade and technical counterparts. Under the latest fishing agreement concluded by Senegal and the European Union (1997-2001), direct financial compensation amounts to about CFAF 32 billion. Despite its economic and social importance, the sector has to face serious disequilibria both in resource exploitation and market supply: the coastal demersal (deep lying fish) stocks with high market value (mostly exported) are fully and even over-exploited, with a serious risk of local market supply shortages looming ahead as the fishing effort shifts from locally consumed species to export-oriented ones.

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Research of the impact of material and flow properties on fluid-structure interaction in cage systems

  • Mehmet Emin Ozdemir;Murat Yaylaci
    • Wind and Structures
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    • v.36 no.1
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    • pp.31-40
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    • 2023
  • This paper investigates the mechanical behavior of full-scale offshore fish cages under hydrodynamic loads. To simulate different cases, different materials were used in the fish cage and analyzed under different flow velocities. The cage system is studied in two parts: net cage and floating collar. Analyses were performed with the ANSYS Workbench program, which allows the Finite Element Method (FEM) and Computational Fluid Dynamics (CFD) method to be used together. Firstly, the fish cage was designed, and adjusted for FSI: Fluid (Fluent) analysis. Secondly, mesh structures were created, and hydrodynamic loads acting on the cage elements were calculated. Finally, the hydrodynamic loads were transferred to the mechanical model and applied as a pressure on the geometry. In this study, the equivalent (von Mises) stress, equivalent strain, and total deformation values of cage elements under hydrodynamic loads were investigated. The data obtained from the analyses were presented as figures and tables. As a result, it has been shown that it is appropriate to use all the materials examined for the net cage and the floating collar.

Species Composition of Fish Assemblage in a Small Scale Eelgrass Bed of Tongyeong, Korea (경남 통영의 소규모 잘피밭 어류군집에 관한 연구)

  • Kim, Jun-Sop;Gwak, Woo-Seok
    • Korean Journal of Ichthyology
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    • v.24 no.3
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    • pp.191-200
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    • 2012
  • Fish species composition in eelgrass bed of Punghwa-ri in Tongyeong, Korea was determined using monthly samples collected by a surf net from November 2010 to October 2011. During the study period, a total of 30 species, 5,511 individuals and 6,933.4 g of fishes were collected. The dominant fish species were Pholis nebulosa, Syngnathus schlegeli, Rudarius ercodes, Pseudoblennius cottoides, Sebastes inermis, and Aulichthys japonicus which accounted for 93.4% of total number of individuals collected. Most fishes collected in the eelgrass bed belong mainly to small fish species or juveniles of large fish species. Eelgrass shoot density reached a peak in April 2011, and then decreased to a minimum in January 2011. The seasonal variation of fish assemblage in an eelgrass bed of Punghwa-ri was correlated to the variations in the water temperature, eelgrass density and biomass, and abundances of major prey organisms.

A Comparative Study on Limno-biological Aspects of the Dammed Lakes in the Youngsan River in Korea - Centering on Fish Fauna - (영산강 수계 댐호의 육수생물학적 비교연구 ( 1 ) - 어류상을 중심으로 -)

  • Nah, Chang-Soo
    • The Korean Journal of Ecology
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    • v.12 no.1
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    • pp.51-65
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    • 1989
  • Some aspects of limno-biology of the five dammed lakes such as Tamyang, Changsong, Kwangju, Naju, and Youngsan Lake along the Yongsan River were investigated from June 1986 to July 1988 for the comparison on the lentic ecosystems in relation to the fish fauna. Sixty four fish species representing 48 genera and 21 families of fishes were collected in these dammed areas, which included 29 species of the family Cyprinidea and 40 speaies of the primary fresh-water fishes. Among, these, 12 species such as Rhodeus Acheilognothus yamatsutae, A canathorhodeus gracilis, Sarcocheilichthys nigripinis morii, S. variegatus wakiyae, Gnathopogon strigatus, Squalidus gracilis majimae, Microphysogobio yaluensis, Cobitis longicorpus sp, Liobagrus mediadiposalis and Odontobutis platycephala are enddmic to Korea. Leiocassis nitidus and Gasterosteus aculeatus which occur in these water areas take note of the zooge rographic study of Korea. The fish species in each of the dammed lakes is in proportion of the scale of the lakes such as 32 species in Thamyang, 40 species in Changsong, 24 species in Kwangju, 35 species in Jaju, and 52 species in Yongsan Lake. The dominant fish species of the 4 upper dammed lakes of Thamyang, Changsong, Kwangju and Naju Lake are Zacco platypus and Rhodeus uyekii, while those of Youngsan Lake are Hemiculter eigenmanni and Carassius auratus. This difference of fish species of those areas suggests that the upper damed lake differ from the lower dammed lakes in the habitable condition of fishes. The migratory fish species have significantly declined and will continue to decline in both population size and number of species in the dammed lakes in near future as a result of the dam construction barriers in the river estuary. The major migratory fishes of this water area are as follows; Anguilla japonica, Plecoglossus altivelis, Hypomesus olidus, Gasterosteus aculeatus, Konosirus Punctatus, Coilia ectens, Hemirhampus sajori, Mugil cephalus. Acanthogobius flavimanus, and Takifugu ocellatus.

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Fish Fauna and Community Structure in Lake Paldang and its Inflows (팔당호의 어류상과 군집동태)

  • Byeon, Myeong-Seop;Park, Hae-Kyung;Lee, Wan-Ok;Kong, Dongsoo
    • Journal of Korean Society on Water Environment
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    • v.24 no.2
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    • pp.206-213
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    • 2008
  • Fish fauna and community structure were investigated at 2003, 2004 and 2006 in Lake Paldang and its inflows. In this survey, we collected 54 species belong to 14 families. Family Cyprinidae take 51.9% (28 species), Cobitidae and Gobiidae occupied 7.4% (each 4 species), respectively. E. erythropterus (11.8%) was dominant species and L. macrochirus (10.2%), designated as an ecosystem-invasive alien fish species by Ministry of Environment, M. yaluensis (9.1%), Z. platypus (7.7%) and R. brunneus (6.7%) were dominated in turn. H. molitrix, C. lutheri, P. altivelis, S. microdorsalis, L. costata. S. gracilis majimae, A. rivularis, P. koreanus. S. scherzeri and O. platycephala were rare species (less than 0.1% in relative abundance). In-lake area, 36 species of fishes belonging to 11 families were collected, and 48 species of 13 families were from inflows. The number of Korean endemic species were 19 species (35.2%), and 4 kinds of exotic species (7.4%), that is, C. cuvieri, H. molitrix, L. macrochirus and M. salmoides were found at this survey area. It was revealed by the analysis of fish community that diversity and richness indices were prominent at tributaries, and dominance index was high at the main body of Lake Paldang. Fish fauna showed rapid decline after dam construction which make the mid-Han river systems to lentic ecosystem, so many of meander-riffle fishes were disappeared dramatically. But after 1990s when installation of small scale wastewater treatment plants started in watershed, the water quality of small tributaries was improved. And also, expansion of the natural macrophytic vegetation of littoral zone should contribute to the development of diverse fish fauna in Lake Paldang.

Oily Fish Consumption Modifies the Association between CD36 rs6969989 Polymorphism and Lipid Profiles in Korean Women

  • Shin, Yoonjin;Kim, Yangha
    • Preventive Nutrition and Food Science
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    • v.21 no.3
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    • pp.202-207
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    • 2016
  • The aim of this study was to investigate the association of CD36, a class B scavenger receptor, rs6969989 polymorphism with the serum lipid profiles in Korean women, together with their modulation by oily fish consumption. Subjects were participants from the Korean Genome Epidemiology Study (KoGES), which was initiated in 2001 as a large-scale. A total of 4,210 women aged 39 to 70 were included in this study. Data were collected using self-administered questionnaires, anthropometric measurements, and blood chemical analysis. Dietary intake was analyzed using a semi-quantitative food frequency questionnaire. The minor allele frequency for rs6969989 was found in 12% of this population. Homozygotes minor G allele at the rs6868989 exhibited significantly higher high density lipoprotein cholesterol (HDLC) concentrations (P-trend=0.043) and lower fasting glucose (P-trend=0.013) than major allele A carriers. The risk of low HDL-C was significantly lower in homozygotes for the G allele than the A allele carriers (P-trend=0.032). Gene-diet interaction effects between rs6969989 and oily fish intake were significantly associated with the risk of dyslipidemia (P-interaction=0.004). Subjects with homozygotes minor G allele and high oily fish intake generally had a lower risk of dyslipidemia than did those with major allele homozygotes and low oily fish intake. These findings supported that oily fish consumption may modulate the contributions of CD36 rs6969989 on genetic predisposition to the risk of dyslipidemia.

Effect of Lowering the pH with Citric Acid on Histamine Formated in Salt-fermented Anchovy Engraulis japonicus Fish Sauce During the Initial Fermentation Stage (Citric Acid에 의한 원료 멸치(Engraulis japonicus) pH가 발효초기 멸치 액젓의 히스타민 생성에 미치는 영향)

  • Kil Bo Shim;Woo Jin Lee;Byoung Kyu An;Jung Jin In;Hyeong Gu Han;Seung Ah Son
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.56 no.2
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    • pp.253-258
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    • 2023
  • This study was conducted to inhibit histamine formation in salt-fermented anchovy Engraulis japonicus fish sauce, by lowering the pH using 1% citric acid as food additive during the initial fermentation stage. The fish sauce samples were prepared with fresh anchovies used immediately after being caught (F), and left at ambient temperature for 4 h, and 24 h with 25% salt, 1% citric acid, and without citric acid for a 6-month fermentation period. The content of ammonia nitrogen, total nitrogen, and glutamic acid in fish sauce was unaffected by the addition of citric acid during the fermentation period. The histamine content of F and 4 h samples were 20.5-30.6 and 77.4-119.3 mg/kg, respectively. The histamine content of F and 4 h samples with 1% citric acid was 4.1-8.7 and 50.4-56.1 mg/kg, respectively. Furthermore, addition of citric acid did not inhibit histamine formation in 24 h sample that had lower freshness quality. Additionally, effective inhibition of histamine is observed during manufacturing of salt-fermented anchovy fish sauce on an industrial scale, suggesting that lowering the initial pH using 1% citric acid does not alter the taste and flavor of the fish sauce.

Effects of the Extruded Pellets and Raw Fish-Based Moist Pellet on Growth and Body Composition of Flounder, Paralichthys olivaceus L. for 10 Months (상업용 부상사료와 어분기초생사료가 넙치의 성장과 체조성에 미치는 영향)

  • Cho Sung Hwoan;Lee Sang-Min;Lee Jong Ha
    • Journal of Aquaculture
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    • v.18 no.1
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    • pp.60-65
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    • 2005
  • Effects of the commercially available or formulated extruded pellets (EP) and raw fish-based moist pellet (MP) on growth and body composition of flounder Paralichthys olivaceus L. were evaluated on commercial scale for 10 months. Survivals of flounder fed the MP, EP 1 and EP3 were not significantly different from those of fish fed the EP2 or EP5, but significantly (P<0.05) higher than that of fish fed the EP4. Weight gain of fish fed the MP was not significantly different from that of fish fed the EP3 and EP5, but significantly (P<0.05) higher than that of fish fed the EP1, EP2 or EP4. Improvement in weight gain of flounder fed the high lipid diets (EP1, EP2, EP3) compared to low lipid diet (EP4) in the $55\%$ protein level, and weight gain of fish fed the high lipid diet (MP) compared to low lipid diet (EP5) in the $61\%$ protein level indicated protein-sparing effect of lipid. FER for flounder fed the EP3. which was not significantly different from that for fish fed the EP1 or EP5 was significantly (P<0.05) higher thar. that for fish fed the EP2, EP4 and MP. FER significantly (P<0.05) changed over time. CF of flounder fed the MP was significantly (P<0.05) higher than that of fish fed EP1 or EP4. Moisture content of dorsal muscle in flounder fed the EP2 was significantly (P<0.05) higher than that in fish fed the EP1 or EP4. Crude protein content of dorsal. muscle in flounder fed the EP1, EP4 and EP5 was significantly (P<0.05) higher than that in fish fed the EP2. How- ever, crude lipid content of dorsal muscle, and moisture, crude protein and crude lipid content of liver in flounder was not significantly different among the diets. In considering performance of flounder, it can be concluded that the use of EP3 and EP5 is more recommendable than the MP, which commonly used in flounder farm.