• 제목/요약/키워드: FISH POPULATION

검색결과 468건 처리시간 0.02초

인구 증가에 따른 식품 수급 추이에 관한 연구-일제시대부터 1980년대까지- (The Study on the Change of Food Supply and Demand in According to Population Growth)

  • 윤애란
    • Journal of Nutrition and Health
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    • 제22권2호
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    • pp.108-117
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    • 1989
  • The purpose of this study was aimed to investigate the historical tends of population growth which has reflected direct effect of the ratio of food self sufficiency in Korea between the year of 1910 and 1980. Author divided the whole years between 1910 and 1980 into five different periods ; colonial period from 1910 to 1945, post colonial period from 1945 to 1950, Korean war period from 1950 to 1955, post Korean war period from 1955 to 1960, fast economic growing period 1960~1980. The ratio of national food self sufficiency has been profoundlly affected by dual factors ; rate of population group and increment of GNP which reflect the national economic development. Total food production never reached the level of population growth ratio in Korea. As a result food demand and supply has shown imbalaced condition which leads to import foods from outside contury to compensate food shortage. The increment of GNP sharply cut down the cereal consumption. The consumption of fish, milk, eggs and meat reflected to increase since 1970.

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METHYLMERCURY EXPOSURE IN CURRENT JAPANESE: ESTIMATION FROM HAIR ANALYSIS

  • Yasutake, Akira;Hachiya, Noriyuki
    • 한국환경보건학회:학술대회논문집
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    • 한국환경보건학회 2005년도 Proceedings of KSEH.Minamata Forum
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    • pp.4-15
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    • 2005
  • Methylmercury (MeHg) is an environmental pollutant with neurotoxic effects on the central nervous system. The major exposure route of MeHg to humans is via consumption of fish and shellfish which accumulate the chemical through the food web in an aquatic environment. Hair mercury level is an excellent marker for MeHg exposure. We have been conducting a survey on hair mercury contents among general populations from 14 districts to estimate the current Japanese MeHg exposure level. Total mercury levels of all hair samples collected (12923 in total) were analyzed by the oxygen combustion-gold amalgamation method using an atomic absorption mercury detector. Multiple regression analysis revealed that mercury levels were significantly correlated with several covariates, such as sex, age, the amount of daily intake of total fish/shellfish, a preference for certain fish such as tuna or bonito, and artificial waving. The geometric means for the population without artificial waving were 2.47 and 1.65 ${\mu}g/g$ for males (n = 5623) and females (n = 3470), respectively. Hair mercury levels varied with age, and the variations were more significant in males. Since the difference between sexes was not evident at younger ages, some hormonal control might also be involved in the mercury uptake by human hair. The average mercury levels in our hair samples varied among the sampling districts. Tuna is a major carnivorous fish with high mercury accumulations that is often consumed in Japan. The amount of fish consumption and the preference rate far tuna would appear to be responsible far the regional variation in hair mercury levels in Japan. Recently, a provisional tolerable weekly intake (PTWI) of MeHg was revised by 61st JECFA to 1.6 ${\mu}g/kg/week$, which was about half that of the Japanese standard, and corresponded to a hair level of 2.2 ppm. The distribution of hair mercury levels in Japanese populations in the present study indicated that 25% of the Japanese females of child-bearing age were estimated to be exposed to MeHg over the PTWI level. This would reflect the high Japanese consumption of marine products. However, not only mercury contamination, but also the nutritional benefit may have to be considered when discussing the risk involved in the current level of fish and shellfish consumption in Japan.

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한강수계 댐호의 블루길, Lepomis macrochirus 개체군 구조 (Population Structure of Bluegill, Lepomis macrochirus in Lakes of the Han River System, Korea)

  • 송호복;변명섭;강동원;장창열;문정숙;박혜경
    • 한국어류학회지
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    • 제24권4호
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    • pp.278-286
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    • 2012
  • 본 연구는 국내 수계에 심각한 위해를 가하고 있는 블루길의 효과적인 관리방안을 위한 기초 자료를 제공하고자 하였으며, 한강수계에 서식하는 개체군을 대상으로 2009년부터 2012년 사이에 연구를 실시하였다. 한강수계에 위치한 대부분의 댐호에는 불루길이 출현하였으며 하천의 경우 하류역에 국한되어 서식하였다. 각 댐호의 개체수 상대풍부도는 0.2~18.2%의 범위였으며 대부분의 댐호에서 아우점종이거나 우세종에 속하였다. 생체량 상대풍부도는 0.2~40.0%였다. 개체군 동태는 소양호와 팔당호는 r-전략형, 의암호와 청평호는 K-전략형, 충주호는 K-전략형에서 r-전략형으로 이행하는 단계로 판단되었다. 비만도와 체중-전장의 관계는 모두 양호한 상태를 나타내었다. 산란장은 집단을 형성하여 조성하였으며 산란둥지의 직경은 평균 42.4 cm, 깊이는 평균 9.7 cm였고, 둥지가 위치한 평균 수심은 56.3 cm, 수변으로부터의 거리는 평균 191.9 cm이었다. 본 연구 결과는 향후 블루길의 개체군 동향 예측과 번식생태 등을 파악하는데 유용한 자료가 될 것으로 본다.

Variations in Species Composition, Biomass, and Density in Shrimp Trawl Bycatch Across Seasons and Tidal Phases in Southern Korean Waters: Developing a Fisheries Risk Management Approach

  • Oh, Chul-Woong;Kim, Sung-Tae;Na, Jong-Hun
    • Fisheries and Aquatic Sciences
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    • 제12권2호
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    • pp.138-151
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    • 2009
  • We quantitatively investigated compositions of fish and invertebrate bycatch in Korean shrimp fisheries. We sampled shrimp trawl bycatch from 48 commercial trawls over 1 year. These samples contained 108 taxa from 50 families, with 60 fish taxa contributing 51.2% of the total biomass and 48 invertebrate taxa 48.8%. However, 86.32% of the total individual organism density comprised invertebrates, while individual fishes made up the remainder. Within the bycatch, two fish species varied in population size structure by season, suggesting recruitment is seasonal in these taxa. Overall general catch characteristics (total bycatch biomass and organism density) varied significantly by season and tide, and a significant interaction effect was observed (season$\times$tide) on total density, but not on total biomass. The data collected will be used in designing a program of long-term bycatch monitoring.

Fisheries Resources -A Brief Introduction of the Republic of Senegal

  • Mbengue, Modou
    • 한국해양바이오학회지
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    • 제3권1호
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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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한국에서 발생한 시구아테라: 증례보고 (Ciguatera fish poisoning in Korea: a case report)

  • 강정호;이성근
    • 대한임상독성학회지
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    • 제19권1호
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    • pp.55-58
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    • 2021
  • Ciguatera is the commonest syndrome of marine poisoning that is caused by the ingestion of ciguatoxins that accumulate in certain tropical and subtropical finfish. It is endemic throughout the subtropical and tropical regions of the Indo-Pacific and Caribbean and has been rarely reported in Korea. With the expansion of travel, tourism, and the import of fish from the tropics, ciguatera poisoning now affects a diverse population. We report a case of ciguatera in a 70-year-old woman, presenting with general paralysis and coma, which developed after consuming codfish and mackerel in Korea.

Otolith microchemistry reveals the migration patterns of the flathead grey mullet Mugil cephalus (Pisces: Mugilidae) in Korean waters

  • Bae, Seung Eun;Kim, Jin-Koo
    • Journal of Ecology and Environment
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    • 제44권3호
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    • pp.185-195
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    • 2020
  • Background: The flathead grey mullet Mugil cephalus has the widest distribution among mugilid species. Recent studies based on mitochondrial DNA sequences showed that the species comprises at least 14 different groups, three of which occur in the northwest Pacific. We analyzed the otolith microchemistry of M. cephalus at several locations in Korea to improve understanding of migration pattern and population origin. Results: We collected 123 sagittal otoliths from seven locations and determined their concentrations of eight elements (7Li, 24Mg, 55Mn, 57Fe, 60Ni, 63Cu, 88Sr, and 138Ba) using laser ablation inductively coupled plasma mass spectrometry. Mean otolith elemental ratios differed significantly among the locations. The Sr:Ca, Fe:Ca, and Ba:Ca ratios were significantly higher than others, and useful chemical signatures for investigating the habitat use of M. cephalus populations. We identified five diverse and complicated migration patterns using the otolith data that we collected: estuarine resident (type I), freshwater migrant (type II), estuarine migrant (type III), seawater resident (type IV), and seawater migrant (type V). A canonical discriminant analysis plot revealed separation of two groups (type II in the Yellow Sea vs. other types in remaining locations). Two locations on Jeju Island, despite their close proximity, had fish with quite different migration patterns, corroborating previous molecular studies that distinguished two groups of fishes. Conclusion: We successfully showed that the migration patterns of the Korean mullet varied by location. Only fish from the western sector of Jeju had a unique migration pattern, which is likely confined population in this area. Among the eight otolith elements measured, the Sr:Ca ratio was found to be the best indicator of migration pattern and population origin.

황금색 넙치(Paralichthys olivaceus)의 발현을 예측할 수 있는 Microsatellite Marker 개발 (Identification of Genetic Markers Distinguishing Golden Flounders from Normal Olive Flounders Paralichthys olivaceus Using Microsatellite Markers)

  • 김민성;곽주리;김태환;한재용;박지빈;조현경;서종표;이우재
    • 한국수산과학회지
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    • 제53권4호
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    • pp.492-498
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    • 2020
  • Despite its economic importance, olive flounder Paralichthys olivaceus aquaculture industry is facing a crisis with a continuous production decline. There have been many solutions to overcome the complicate predicament proposed. Increasing genetic diversity and discovering new commercial value through selective breeding are among them. The aims of the present study are to increase the selection power of the golden flounders. We examined the genetic diversity of the breeder population of golden flounders and developed selective markers for the golden flounder population. The 6 microsatellite (MS) markers were selected from melanogenesis-related genes, which are believed to be involved in the pigmentation of fish. All markers were polymorphic (except PO4) and 5 of them had PIC value of 0.6 or above. All makers had distinctive alleles indicating either normal or golden individuals. For examples, from PO4 marker, the frequency of an allele (316) in the golden population was 100% and in normal population was 0% (P<0.001). Although some more studies with more samples at the later generations should be performed to confirm this result, the 316 allele from PO4 marker could be a distinctive tool for decision of the colors in olive flounders at an early stage of the life cycle.

Genetic Diversity of Thread-sail Filefish Stephanolepis cirrhifer Populations in Korean Coastal Waters Inferred from Mitochondrial DNA Sequence Analysis

  • Yoon, Moon-Geun;Jung, Ju-Yeon;Nam, Yoon-Kwon;Kim, Dong-Soo
    • Fisheries and Aquatic Sciences
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    • 제14권1호
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    • pp.16-21
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    • 2011
  • The genetic diversity and population genetic structure of thread-sail filefish, Stephanolepis cirrhifer (Temminck & Schlegel), were examined with a nucleotide sequence analysis of a 495bp fragment of the 5'-end of the cytochrome b gene in 113 fish collected from five populations from the south and east coasts of the Korean Peninsula. Seventeen variable nucleotide sites and 16 haplotypes were defined. The observed haplotypes had a shallow haplotype genealogy and no geographical association. Most of the populations had high haplotype diversity and low nucleotide diversity, and significant negative values for Fu's $F_S$, suggesting rapid, recent population growth from an ancestral population and sudden population expansion. The estimated pairwise fixation indices ($F_{ST}$) indicate that substantial gene flow occurs among these populations. Thread-sail filefish in the South Sea of Korea and East Sea Korean populations forms a single panmictic population. Thus, thread-sail filefish in these areas should be treated as one management unit.

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

  • Nah, Chang-Soo
    • The Korean Journal of Ecology
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    • 제12권1호
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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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