• 제목/요약/키워드: Spawning ground

검색결과 85건 처리시간 0.024초

사천만과 남해연안에서 새우조망에 어획된 어류의 종조성 및 군집구조 (Species composition and community structure of fish by shrimp beam trawl between Sacheon Bay and coastal waters off Namhae, Korea)

  • 송세현;정재묵;이승환;김도훈
    • 수산해양기술연구
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    • 제55권3호
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    • pp.217-232
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    • 2019
  • It was turned out by shrimp beam trawl monthly survey from March, 2015 to February, 2016 that different species composition and abundance of the fish assemblages in Sacheon Bay and coastal waters off Namhae, Korea were compared. As a result of monthly measured sea temperature and salinity of Sacheon Bay and coastal waters off Namhae, sea temperature of both areas was changed seasonally; however, differences in sea temperature occurred during certain periods depending on the region. Salinity was generally low in Sacheon Bay affected by fresh water, and both areas was low in summer and high in winter. A total of 73 species representing 37 families were collected in Sacheon Bay. The dominant fish species in terms of numbers and biomass were Liparis tanakae, $23,077inds./km^2$, $332.1kg/km^2$. A total of 91 fish species representing 49 families were collected in coastal waters off Namhae. The dominant fish species in terms of numbers were Leiognathus nuchalis, $139,683inds./km^2$ and biomass were Chelidonichthys spinosus, $1,078.6kg/km^2$. Analysis of dendrogram of the clustering showed that Sacheon Bay and coastal waters off Namhae were distinctive featured (global R = 0.691, p = 0.017). And except of summer season (July-October), there was a distinctive feature seasonally (global R = 0.844, p = 0.001). The fish species that appeared in common in both areas, where fish species caught in Sacheon Bay, an important inner bay,were smaller than those caught in coastal waters off Namhae appeared. It presented that Sacheon Bay plays a more important role in spawning and nursery ground for fisheries resource than coastal waters off Namhae, Korea.

연어(Oncorhynchus keta)의 밀양강 분포 및 소상 한계선 파악 (The Distribution and Migration Boundary Lines of Oncorhynchus keta in the Milyang River)

  • 홍동현;성기백;고의정;정은송;조현빈;주기재
    • 생태와환경
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    • 제53권4호
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    • pp.445-452
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    • 2020
  • 본 연구는 낙동강지류인 밀양강에 소상한 연어를 대상으로 소상, 산란 분포를 최초로 파악하고 소상 한계선을 확인하였다. 2020년 10월 25일부터 11월 28일까지 확인된 개체들 중, 사체는 전장을 측정하고 암-수 구별을 하였다. 조사 결과 총 40개체의 연어를 발견하였으며 이 중 사체는 25마리, 살아있는 개체는 15마리였다. 대부분 산란장으로 판단되는 지점 인근 수변부에서 살아있는 개체와 사체가 발견되었다. 연어의 소상 한계선 파악의 경우 연어가 소상할 수 없는 형태의 보가 등장할 때까지 상류방향으로 이동하여 확인하였으며, 밀양강 본류의 경우 예림교 기준 상류 13 km, 지천인 단장천의 경우 밀양강 합류부에서부터 12 km까지 연어의 소상이 가능할 것으로 확인하였다. 따라서 연어가 소상하기 위한 보의 철거 및 어도설치와 같은 하천연결성 확보가 필요한 것으로 판단되며, 연어의 치어생존률을 높이기 위한 산란장 및 미소서식처 자연성 확보 방안이 필요할 것으로 판단된다.

Detection of frog and aquatic insects by environmental DNA in paddy water ecology

  • Keonhee Kim;Sera Kwon;Alongsaemi Noh
    • 농업과학연구
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    • 제50권2호
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    • pp.257-270
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    • 2023
  • 논(paddy) 환경은 습지로 분류되며 담수환경에서 매우 많은 비율을 차지하고 있다. 또한 많은 수서곤충류 및 양서파충류 유생의 서식지 및 산란 장소로써 생태학적으로 매우 중요하다. 하지만 기후변화 및 무분별한 농약 살포 등으로 인해 논 생태계는 지속적으로 위협받고 있다. 따라서 향후 훼손된 논 생태계를 복원하기 위해서는 복원 기준이 될 수 있는 논 생태계 서식 생물들의 정보가 필요하다. 환경유전자 metabarcoding 분석법은 성체 생활시기가 다르거나 성충으로 우화하여 대상 생태계에서 더 이상 발견할 수 없는 분류군까지 존재 여부를 간접적으로 파악할 수 있기 때문에 논 생태계에 서식하는 많은 생물들의 정보를 축적하는데 매우 효과적이다. 본 연구에서도 4종의 개구리와 9종의 수서곤충 유전자가 발견되었으며, 일부 분류군은 현장에서 개체가 직접 발견되었다. 많은 수의 분류군이 DNA 탐색에서만 발견되었으며, 전통적인 조사방법은 매우 제한적인 분류군만을 확인할 수 있었다. 이러한 eDNA 기반의 논 생물탐색은 강력한 분석 해상도 때문에 농업 생태계 생물다양성 조사에서 활용가치가 매우 높을 것으로 판단된다.

한국 서해 남부해역에서 채집된 도화뱅어, Neosalanx anderssoni (뱅어과) 자치어의 분자 동정 및 첫 형태기재 (Molecular Identification and First Morphological Description of Larvae and Juveniles of Neosalanx anderssoni (Salangidae) Collected from the Southwestern Sea of Korea)

  • 구서연;명세훈;김진구
    • 한국어류학회지
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    • 제36권1호
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    • pp.94-100
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    • 2024
  • 본 연구는 2023년 4~5월 전라남도 영광군 칠산도 주변 해역에서 채집된 뱅어과(Salangidae) 자치어 총 6개체를 대상으로 분자 동정과 발달단계별 형태특징을 상세히 기재하였다. MtDNA COI 또는 16S 영역을 대상으로 분자 분석을 진행한 결과, 자치어 6개체는 도화뱅어(Neosalanx anderssoni) 성어와 유전거리 0~0.2%의 차이를 보여 도화뱅어로 동정되었다. 도화뱅어 자치어 6개체는 모두 측편형의 가늘고 긴 체형을 보였다. 전기자어~중기자어(10.24 mm NL, 13.37 mm SL) 시기에는 복강의 배쪽에 타원형의 흑색소포가, 복강 등쪽에는 옅은 점 모양의 흑색소포가 열을 이루었다. 반면 후기자어~치어 시기(22.12 mm SL, 28.43 mm SL)에는 복강 배쪽의 흑색소포가 사라지고 복강 등쪽의 흑색소포가 수적으로 증가하여 1열로 나타났다. 또한, 후기자어 시기부터는 꼬리지느러미에 크고 짙은 검은 반점 2개가 대칭적으로 나타났다. 본 연구 결과는 이전의 연구 결과(Kim and Park, 2002)와 달리 도화뱅어가 연안을 산란 또는 성육장으로 이용할 수 있음을 시사한다.

북한수산업(北韓水產業)의 현황(現況)과 전망(展望) (Present Status and Future Prospect on Fishing Industry in North Korea)

  • 이병기;김진건;최종하
    • 수산해양교육연구
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    • 제3권2호
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    • pp.73-82
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    • 1991
  • In recent years, the communication and the trade between the Republic of Korea(South Korea) and the Communist bloc has been activated. The simultaneous entrance of South Korea and North Korea to the United Nations will accelerate the political dialogue and also the trade which is indirectly carried out through a third country at present will be turned into direct way. Fisheries products are also treated as one of the important trade goods and there is a hopeful prospect that the amount of trade will be steeply increased in the near future. Furthermore, there is a great possibility of development up to the joint utilization of fishing grounds or the joint investment in fisheries projects. Concerning such points, since it is very much important to understand the present status of fisheries in North Korea, the author made a study on this field as requested by the Board of Unification, and report a part of the study here. The prominent character of North Korea's ruling sea area is that the sea is completely separated into two regions-the East Sea Region and the West Sea Region-and no continuity exists between them. The East Sea Region locates in the fringe of the biggest fishing ground of the world-the North Pacific Ocean-and very rich in resources not only warm water fishes but also cold water fishes. Especially alaska pollack, Theragra chalcogramma, is caught abundantly in this region. Contrary to that, fishing activity in the West Sea Region seems to be interrupted in winter. Even though some valuable warm water fishes-yellow corvenia, Pseudosciaena manchurica, and hair tail, Trichiurus lepturus, and so forth-come to this region from spring to summer along the coast line of this region for spawning, and vigorous fishing activity is carried out. But the most of them migrate southward to the neighboring waters of Cheju Island for wintering from autumn to winter, and so the fishing activity in this region seems to be interrupted greatly during winter. The total number of fishing boats in North Korea is estimated at 36 thousand and the rate of mechnization at about 70% compared with 99 thousand and 78% in South Korea. North Korea proclaimed an exclusive economic zone of 200 nautical miles in 1977. Specific character of this zone is setting of military boundary zone, up to 50 miles from the base line in the East Sea Region and also it covers whole region of the economic zone in the West Sea Region. Especially in the East Sea Region she set up a straight base line which can not be permissible by the international law. North Korea's statistics on fisheries product has not been announced officially on account of her unique isolationism, but it can be estimated through several data procured. At the first, the amount of fisheries products in the North Korea is reported as about 1.7 million ${\frac{M}{T}}$ by Fisheries Statistics which issued by the FAO in 1987, but a North Korea's trade organization announced the amount as 3.5 million ${\frac{M}{T}}$ in 1988. The former seems to be underestimated and the latter must be an exaggeration. According to Chikuni, who is a Japanese worker for FAO, prepared the unofficial statistics based on the evidence which he collected through the fineries development plan of the FAO/UNDP, and estimated the mean amount between 1982 and 1984 was 2.4 million ${\frac{M}{T}}$ or so. The Board of Unification estimated on the basis of various factors that the amount was 2.2 million ${\frac{M}{T}}$ or so in 1987 and in 1988. This seems to be the most reasonable. To solve the chronic lack of foreign currency, North Korea makes effort on the development of fisheries, and has even aimed fisheries product at 11 million ${\frac{M}{T}}$ by 1993, but this target looks unrealistic under the present circumstances. Somehow, we can exploit her extreme policy which has gone so far as to establish such an excessive and impractical target. Nevertheless this will be helpful to promote the joint development of the fishery activity between South Korea and North Korea.

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