• Title/Summary/Keyword: Dokdo

Search Result 348, Processing Time 0.043 seconds

First Description of the Adult Scolecenchelys aoki (Ophichthidae, Anguilliformes) Collected from the South Sea of Korea, with Comments on the Synonym Scolecenchelys borealis (한국 남해에서 채집된 동해물뱀(Scolecenchelys aoki) 성어의 첫기재 및 Scolecenchelys borealis의 동종이명에 관한 검토)

  • Ji, Hwan-Sung;Kim, Maeng Jin;Kim, Jin-Koo
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.46 no.5
    • /
    • pp.589-593
    • /
    • 2013
  • Scolecenchelys borealis was first added to the Korean fish fauna based on one leptocephalus specimen (total length (TL) 59.2 mm) collected from Dokdo, in the East Sea. Recently, however, Scolecenchelys borealis has been treated as a junior synonym of Scolecenchelys aoki, necessitating review of the scientific name S. borealis. This study describes the morphological characteristics of S. aoki based on an adult specimen (TL 230.0 mm) collected from the sea south of Korea and compares its mitochondrial DNA 12S rRNA sequence with that of the S. borealis leptocephalus. The adult S. aoki is characterized by several morphological features: vertebral formula 59-55-135; preanal lateral pores 55; infraorbital pores two; teeth on upper jaw visible externally when the mouth is closed; the dorsal fin originates just behind the anus; both jaws and vomerine teeth are conical, arranged in two rows. An analysis of an 886-base paire sequence of the 12S rRNA showed that adult S. aoki was concordant with the S. borealis leptocephalus (sensu Ji et al., 2012), indicating that both are the same species.

Natural hatching-induced and management for Pacific herring Clupea pallasii eggs attached to the gill net (그물에 부착한 청어 (Clupea pallasii) 어란의 자연 부화유도 및 관리방안)

  • JI, Hwan-Sung;LEE, Dong Woo;CHOI, Jung Hwa;CHOI, Kwang Ho
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.51 no.3
    • /
    • pp.370-374
    • /
    • 2015
  • Pacific herring Clupea pallasii eggs were attached to the gill net in Korean coastal waters off Busan. To conservation and management the eggs attached to the gill net, we followed the natural hatching in coastal waters from five days after fertilization to the hatching finished, where the temperature was $9^{\circ}C$. The diameter of fertilized eggs was 1.24-1.55 mm (n= 50), and had a segmented pale yellow yolk, no oil globule. Natural hatching had started by 10 days after fertilization. Mass hatching occurred around 11-12 days after fertilization, most of eggs separated from the gill net. Therefore, when the Pacific herring eggs attached in gill net, should be natural hatching-induced in coastal waters during 12-14 days.

Age and Growth of Jack Mackerel Trachurus japonicus off Jeju Island, Korea (제주 인근해역에 서식하는 전갱이(Trachurus japonicus Temminck et Schlegel)의 연령과 성장)

  • Lee, Dong Jin;Kang, Sukyung;Jung, Kyung-Mi;Cha, Hyung Kee
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.49 no.5
    • /
    • pp.648-656
    • /
    • 2016
  • The age and growth of jack mackerel Trachurus japonicus caught by large purse seine fishery were studied during August 2004 and May 2005. Otoliths of 472 fish were observed under reflected light, and translucent zones made on the post-rostrum axis were regarded as annual marks. Monthly changes in the marginal index indicated that the translucent zone was formed once a year, mainly in March-April, which was coincident with the peak spawning time of jack mackerel. The estimated ages were 0-6 years, corresponding to a fork length (FL) range of 13 to 38 cm. Most obtained individuals were 2-year-old fish, followed by 1-year-old fish. The mean fork length at age from otolith reading (sex combined) was applied to the von Bertalanffy equation and growth parameters were estimated: L = 38.29 cm FL, k = 0.31 years−1, t0 = −0.81 years.

A Study on Construction of Floating Breakwater for Improving Berthing Capacity of Wharf at Dokdo (독도물양장 선박접안율 개선을 위한 부방파제 설치에 관한 연구)

  • Woo, Bong-Chul;Lee, Seung-Oh;Park, Seung-Hyun;Cho, Yong-Sik
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2007.05a
    • /
    • pp.2109-2112
    • /
    • 2007
  • 독도는 울릉도에서도 동남쪽으로 약 87.4km 떨어져 외해의 영향을 많이 받고 있는 지역이지만 방파제 등 외곽시설이 전무하여 평상파랑에도 접안이 어려운 경우가 많아서 독도 관광자원 활용도 및 편의시설 제공면에서 많은 어려움이 있다. 이에 본 연구에서는 독도 접안시설의 전면에 최근 국내에 본격적으로 도입되고 있는 부방파제(floating breakwater)를 설치할 경우 고정식 방파제 설치에 따른 문제점을 충분히 개선할 수 있다고 판단하여, 부방파제 설치에 따른 기술적인 타당성과 부두 이용률 개선효과 등을 연구 하였다. 독도의 접안시설은 해역이 동도와 서도에 의해 북쪽은 일부 차폐되고 남쪽은 직접 노출되어 있는 지리적 특성이 있어 주 파향인 남쪽계열의 8개 파향(SE, SSE, S, SW, SSW, WSW, W, WNW)의 평상파 제어가 가능하도록 방파제를 배치하였고, 이에 따른 부두 이용률 검토결과 부방파제를 설치할 경우 남쪽계열 파랑에 대하여 현상태에 비하여 부두 이용률이 대략 2배정도 증가되는 것으로 나타났으며, 부방파제 계류시스템의 안정에 대해서도 부체에 영향을 주는 외력에 대하여 계류체인의 길이와 Anchor Block 자중의 규모를 적당히 조정하면 충분히 안정한 것으로 검토되었다.

  • PDF

Forecasting biomass and recruits by age-structured spawner-recruit model incorporating environmental variables (환경요인을 결합한 연령구조 재생산모델에 의한 자원량 및 가입량 예측)

  • Lee, Jae Bong;Lee, Dong Woo;Choi, Ilsu;Zhang, Chang Ik
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.48 no.4
    • /
    • pp.445-451
    • /
    • 2012
  • We developed an age-based spawner-recruit model incorporating environmental variables to forecast stock biomass and recruits of pelagic fish in this study. We applied the model to the Tsushima stock of jack mackerel, which is shared by Korea and Japan. The stock biomass of jack mackerel (Trachurus japonicus) around Korean waters ranged from 141 thousand metric tons (mt) and 728 thousand mt and recruits ranged from 27 thousand mt to 283 thousand mt. We hind-casted the stock biomass to evaluate the model performance and robustness for the period of 1987~2009. It was found that the model has been useful to forecast stock biomass and recruits for the period of the lifespan of fish species. The model is also capable of forecasting the long-term period, assuming a certain climatic regime.

A bioeconomic analysis of blackfin flounder Glyptocephalus stelleri fisheries management (기름가자미 어업관리를 위한 생물경제학적 분석)

  • CHOI, Ji-Hoon;CHOI, Wan-Hyun;KIM, Do-Hoon
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.52 no.4
    • /
    • pp.394-402
    • /
    • 2016
  • In order to manage and rebuild fishery resources, the fishing effort should be controlled effectively. Especially in the setting up of the proper level of fishing efforts, economic standards as well as biological standards must be carefully considered to promote the sustainable and economically viable development of fisheries. This study aimed to analyze the optimal economic fishing effort ($E_{MEY}$) as the most economically efficient one for the Eastern Sea Danish seine fisheries. The results showed that the optimal economic fishing effort ($E_{MEY}$) of Eastern Sea Danish seine fisheries for blackfin flounder should be reduced by about 27%. That is, reducing fishing efforts up to the level of $E_{MEY}$ could lead to the reduction of fishing costs, thereby resulting in the increased fishing profits.

Creative Photographs of Daegu·Gyeongbuk Province in 1930's-50's (1930-50년대 대구·경북 사진의 특성)

  • Kim, Tae-Wook
    • The Journal of the Korea Contents Association
    • /
    • v.12 no.7
    • /
    • pp.76-85
    • /
    • 2012
  • Early photography history of Daegu, Gyeongbuk Province, Gyebok Choi were taken a lots of prizes of famous contest and known to the nationwide in 1930's and then his photos became an example of salon photography. And his documents of Mt. Baekdu & Dokdo in 1940's was the outcome of self-consciousness. Wangsam Koo proposed the realism of the photo. He saw, the base of photos should be reflected the lives of people of the times and the characteristics of the period, and he had great influence to the history of Korea photography with his own unique vision. These photos and theories accomplished a photo aesthetic to Korea photo history in 1940's. Besides it had been the national spirit at Youngnam province in the early 20th century.

Comparative study of fruit wall structure in Lapsana L. and Lapsanastrum J. H. Pak & K. Bremer (Asteraceae; Lactuceae) (개보리뺑이속과 서양개보리뺑이속(국화과; 상치족)의 과피벽 구조 비교 연구)

  • Pak, Jae-Hong;Choi, Kyung;Ito, Motorni
    • Korean Journal of Plant Taxonomy
    • /
    • v.38 no.4
    • /
    • pp.359-369
    • /
    • 2008
  • The mature fruit wall structures were investigated in Lapsana communis, its six subspecies and the four species of Lapsanastrum (Asteraceae; Lactuceae). Lapsanastrum differs from Lapsana communis in some features: two or three protrudent costae verse equally developed costae, hairly versus glabrous exocarp, respectively. Moreover, Lapsana has no sclerenchymatous‐fiber cells in mesocarp, while Lapsanastrum has sclerenchymatous fiber cells. The differences in fruit wall structure between Lapsana and Lapsanastrum obviously support the separation of Lapsanastrum from Lapsana s. lat.

The Study of Countermove and Distorted Instances about Korean History in Japanese Game (일본 게임에 나타난 한국 역사의 왜곡사례와 대응방안 연구)

  • Ko Byeong-Hee
    • Journal of Game and Entertainment
    • /
    • v.2 no.2
    • /
    • pp.1-8
    • /
    • 2006
  • The relations between the two countries, Korea and Japan, are growing worse because of the matter of distorting korean history, absurd remark for aggressive war, and claiming Dokdo by Japan. At the point of time, I research the distorted instances of Korean history in Japanese game. The distorted instances of Korean history in game are existed in any countries' game such as China and the West; however, Japanese game takes distorted instances too far. Teenagers in the interior of a country and people from other countries easily access the distorted game because of the development of Internet and promoted cultural exchange among nations so it is necessary that systematic countermeasure should be set.

  • PDF

Genetic diversity and distribution of edible scytosiphonacean algae from Ulleungdo Island, Korea

  • Lee, Ju Il;Jang, Hyeong Seok;Cho, Ga Youn;Yoon, Sung Jin;Boo, Sung Min
    • ALGAE
    • /
    • v.34 no.3
    • /
    • pp.229-236
    • /
    • 2019
  • Despite the abundance of seaweeds from Ulleungdo Island, genetic diversity and distribution of edible brown algae from the island remain unstudied. We analyzed mitochondrial cox3 sequences from 86 specimens collected in the island and from the nearby Korean Peninsula. Our cox3 phylogeny for the first time confirmed the occurrence of fives species from Ulleungdo Island; Petalonia binghamiae, P. fascia, Planosiphon zosterifolius, and two cryptic species previously identified as Scytosiphon lomentaria. P. binghamiae was relatively homogeneous with three haplotypes. P. fascia comprised four haplotypes, which were grouped into two genetic lineages. S. lomentaria was heterogeneous with nine haplotypes and was divided into two cryptic species; one species clustered with taxa from cold waters while the other clustered with taxa from temperate and cold waters. Low genetic diversity in P. binghamiae while high genetic diversity in S. lomentaria from Ulleungdo Island are comparable to patterns observed from other species from the Korean peninsula. Ulleungdo Island, although small in size, is an ideal field laboratory to investigate genetic diversity and distributions of economic marine algae.