• 한국수산과학회지
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• 제54권4호
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• pp.498-507
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• 2021

Ichthyoplankton (fish eggs and larvae) were collected seasonally collected from 2017 to 2019 to clarify whether Dokdo serves as a fish spawning and/or nursery ground. Fish eggs were identified and classified into 16 species. The dominant fish egg species were Engraulis japonicus, Maurolicus japonicus, and Parajulis poecilepterus. Fish larvae were identified and classified into 15 species. The dominant fish larvae species were E. japonicus, M. japonicus, and Sebastes owstoni. A cluster analysis similarity percentages revealed two distinct groupings according to sample location (stations) with E. japonicus and M. japonicus as the main group influencers. E. japonicus was the dominant species off Dokdo. The species diversity and abundance peaked in summer. The diversity index, richness index, and evenness index fluctuated seasonally. There were no predominant species variations among the years. Sedentary species such as P. poecilepterus, Semicossyphus reticulatus, and Glyptocephalus stelleri occurred in the inshore stations. E. japonicus, M. japonicus, and Trachipterus trachypterus occurred in the offshore stations. Our results show these species use Dokdo as spawning and nursery grounds.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권1호
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• pp.53-61
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• 2021

Distribution of fish community depends largely on environmental disturbance such as habitat change. In this study, we evaluated the impact of environmental variables and microhabitat patch types on fish distribution in Yudeung Stream at 15 sites between early May and late June 2019. We used non-metric multidimensional scaling to examine the distribution patterns of fish in each site. Gnathopogon strigatus, Squalidus gracilis majimae, Zacco koreanus, and Zacco platypus were associated with riffle and boulder areas, whereas Iksookimia koreensis, Acheilognathus koreensis, Coreoleuciscus splendidus, Sarcocheilichthys nigripinnis morii, and Odontobutis interrupta were associated with large shallow areas. In contrast, Cyprinus carpio, Carassius auratus, Lepomis macrochirus, and Micropterus salmoides were found at downstream sites associated with large pool areas, sandy/clay-bottomed areas, and vegetated areas. On the basis of these results, we suggest that microhabitat patch types are important in determining the diversity and abundance of fish communities, since a mosaic of different microhabitats supports diverse fish species. As such, microhabitat patches are key components of freshwater stream ecosystem heterogeneity, and a suitable patch composition in stream construction or restoration schemes will support ecologically healthy food webs.

• 한국해양학회지
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• 제25권3호
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• pp.135-144
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• 1990

1984년 9월부터 1985년 8월까지 대천해수욕장 모래질 쇄파대에서 월별로 지인망을 이용하여 어류를 채집하여 계절에 따른 어류군집의 종조성 변화를 분석하였다. 각 조 사시기의 사리 때에 간조 전후 2시간 간격으로 5회 채집을 실시하였다. 출현한 35종 가운데, 날개망둑(Favonigobius gymnqauchen), 청보리멸(Silago japonica), 전어 (Konosirus punctatus), 밴댕이 (Sardinella zunasi) 및, 얼룩망둑(Chaenogobius mororana)이 우점하여 전체 개체수의 79%를 차지하였다. 생체량에서는 전어, 날개망 둑, 청보리멸, 밴댕이 및 돌가자미(Kareius bicoloratus)가 67%를 차지하였다. 연평균 어류의 개체수와 생체량은 각각 0.13개체/m$^2$와 0.33g/m$^2$으로 다른 해역에 비하여 낮 은 값이 관찰되었다. 출현종수, 개체수 및 생체량은 수온과 유의한 상관관계를 보였 다. 봄에는 주거종인 날개망둑이 우점하였으며, 6개월 이종의 성어가 대량 출현하여 높은 생물량이 관찰되었다. 8월에서 9월 사이에서 회유종인 청보리멸, 전어, 밴댕이 등의 유어가 우점하였다. 연구해역 어류군집의 양적 변동은 일차적으로 수온, 혹은 수 온과 상관관계를 갖는 요인에 좌우되며, 우점동일 생활사에 따른 서식처 이동에 의하 여 일년을 주기로 구성종이 계절에 따라 종조성이 변하는 것으로 추정된다.

• ALGAE
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• 제26권3호
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• pp.237-241
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• 2011

The toxic dinoflagellate Karlodinium veneficum has been implicated in numerous fish kill events around the world. Since this species commonly co-occurs with other morphologically similar dinoflagellates, field monitoring of this species in natural waters via light microscopy only has been problematic. In this study, we investigated temporal changes in K. veneficum's abundance in the waters of Obido, Tongyeong, using a species-specific real-time polymerase chain reaction (PCR) assay. The field survey, from April to December 2010, revealed K. veneficum occurred at low densities (12 to 425 cells $L^{-1}$) during this time and that cell numbers peaked in June (early summer in Korea), indicating this species generally occurs in the warmer season (mostly at $16.9-22.3^{\circ}C$ and 33.4-34.5‰) in the Obido area.

• 수산해양기술연구
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• 제53권2호
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• pp.142-151
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• 2017

The fluctuation in the abundance and species composition of fish was investigated using gape net in Dolsan District of Yeosu Korea from July 2015 to April 2016. A total of 1,331 fishes were sampled and classified into 30 orders, 42 families, and 53 species. The dominant orders are Perciformes including 21 famailies and 24 species, followed by Scorpaeniformes including 7 families and 13 species, and Clueiformes including 6 families and 6 species. Among the 53 fish species collected, Engraulis japonicus was the most frequent species occupying 43.5%, followed by Argyrosomus argentatus (23.8%), and Leiognathus nuchalis (22.4%). The monthly diversity, evenness, and richness index were 1.83-2.90, 0.76-0.95 and 3.06-6.40.

• 한국해양학회지
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• 제19권1호
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• pp.1-10
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• 1984

1975年 12月에서 1976年 5月 사이에 濠洲 Cronulla近海에서 實施한 가다랭이 漁業試驗時 採集한 浮游生物과 가다랭이 胃內容物의 造成 및 量的 相互關係性을 分析硏究 하였다. 가다랭이의 먹이생물의 造成과 豊度는 富裕生物의 그것들과 잘 一致하였으며 그 主要먹이 생물로서는 Nyctiphanes australis, brachyura幼生, 정어리種漁 및 Copepoda등임을 밝혔다. 가장 많은 가다랭이 漁獲은 富裕生物組成上 N. australis와 brachyura유생이 가장 豊富했던 1月과 2月에 있었다. 特히 Copepoda중의 Undinula vulgaris는 가다랭이의 먹이생물中 선택적 기호성먹이로서 가치가 큰 것으로 나타났다.

• 한국수산과학회지
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• 제38권6호
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• pp.385-392
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• 2005

Seasonal variation of abundance and species composition of ichthyoplankton were studied in the coastal water off Tongyoung, Korea. Monthly samples were collected using a ring net which were towed horizontally at 4 different stations from March, 1998 to February, 1999. A total of 74 species representing 35 families and 8 orders were found. Of these species 40 species (17 families) were Perciformes. Of the fish larvae couected Engraulis japonicus, Repomucenus sp., Parablennius yatabei, Synechogobius hasta, and Tridentiger sp. were the dominant species representing $80.6\%$ in total number of individuals. The number of species was highest in August and lowest in December; number of individuals was highest in May and lowest in November. The diversity index (Shannon and Wiener Index) was highest in march, and lowest in December.

• 한국수산과학회지
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• 제38권4호
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• pp.265-275
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• 2005

A prerequisite for deriving the abundance estimates from acoustic surveys for commercially important fish species is the identification of target strength measurements for selected fish species. In relation to these needs, the goal of this study was to construct a data bank for converting the acoustic measurements of target strength to biological estimates of fish length and to simultaneously obtain the target strength-fish length relationship. Laboratory measurements of target strength on 15 commercially important fish species were carried out at five frequencies of 50, 70, 75, 120 and 200 kHz by single and split beam methods under the controlled conditions of the fresh and the sea water tanks with the 389 samples of dead and live fishes. The target strength pattern on individual fish of each species was measured as a function of tilt angle, ranging from $-45^{\circ}$ (head down aspect) to $+45^{\circ}$ (head up aspect) in $0.2^{\circ}$ intervals, and the averaged target strength was estimated by assuming the tilt angle distribution as N $(-5.0^{\circ},\;15.0^{\circ})$. The TS to fish length relationship for each species was independently derived by a least-squares fitting procedure. Also, a linear regression analysis for all species was performed to reduce the data to a set of empirical equations showing the variation of target strength to a fish length, wavelength and fish species. For four of the frequencies (50, 75, 120 and 200 kHz), an empirical model for fish target strength (TS, dB) averaged over the dorsal sapect of 602 fishes of 10 species and which spans the fish length (L, m) to wavelength (\Lambda,\;m)$ ratio between 5 and 73 was derived: $TS=19.44\;Log(L)+0.56\;Log(\Lambda)-30.9,\;(r^2=0.53)$.

• Ocean and Polar Research
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• 제42권2호
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• pp.141-155
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• 2020

Species composition of fish in the shallow water at Daecheon beach was determined using monthly beach seine samples collected from April 2010 to March 2011. These data were compared with the previous data, one just after reclamation in 1984-1985, and the other in 1995-96, in order to assess the post-reclamation impact of the environmental change on the fish assemblage. A total of 30 species from 1,464 individuals with biomass of 17,808 g were identified. Dominant species in the number of individuals were Chelon haematocheilus (49.3%), Takifugu niphobles (13.7%) and Paralichthys olivaceus (10.0%). Among pelagic fish, migrant juvenile fish such as Sardinella zunasi and Thryssa kammalensis were abundantly collected in 1984-85, but the catch amount was gradually decreased as time untill only few pelagic fish were collected in 2010-2011. The benthic fish were most abundant in 1984-1985 among habitat groups, and Favonigobius gymnauchen and Kareius bicoloratus were the top two predominants. Species composition of benthic fish did not exhibited drastic changes in 1995-1996, but both the abundance decline and the species composition change was evident in 2010-2011. Among the semi-benthic fish from 1984-1985 samples, Sillago japonica and Konosirus punctatus predominated. Species composition was slightly changed in 1995-1996, but significant changes were met in 2010-2011 with the two predominats, Chelon haematocheilus and Takifufu niphobles. These changes in fish species composition may reflect the post-reclamation effect of the impaired water quality and the accumulation of organic rich fine sediments.

• 한국어류학회지
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• 제22권3호
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• pp.168-178
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• 2010

2006년 2월부터 10월까지 남해 거문도 연안의 암반초와 비 암반 정점의 어류 종조성을 비교 분석하였다. 어류자료는 밤에는 삼중자망으로 수집하였고, 낮에는 스쿠버 잠수관찰로 수집하였다. 조사기간 동안 세 정점에서 삼중자망에는 총 40종, 380마리, 71,426.9 g의 어류가 채집되었다. 어획된 어종 가운데 전갱이가 최우점하였으며, 그 외 홍어, 노랑가오리, 쥐치, 전기가오리, 참돔, 볼락, 꼬치고기 등이 많이 채집되었다. 암반 초 정점에서는 26종, 264마리, 46,776.7 g의 어류가 채집되었고, 우점종은 전갱이이었다. 다음으로 비 암반 정점 1에서는 17종, 45마리, 10,535.1 g의 어류가, 비 암반 정점 2에서는 19종, 71 마리, 14,115.1 g의 어류가 채집되었다. 스쿠버 다이빙에 의한 3정점 잠수조사에서는 13종, 1,749마리의 어류가 관찰되었다. 주로 관찰된 어종은 자리돔이며, 기타 범돔, 쥐치, 망상어, 육동가리돔, 뱅에돔, 용치놀래기, 노래미, 쥐돔, 볼락, 혹돔 등이 관찰되었다. 암반초에서 어류의 풍도는 어종수 7종, 개체수 1,739마리이며, 이는 전체의 99.4%를 차지하는 것이다. 거문도 해역에서 어류군집은 많은 암초성 어류들을 포함하고 있었지만, 전갱이, 고등어 같은 회유성 어종들도 다량 포함하고 있었다. 또한 암반초에서 어류의 풍도는 다른 비암반 정점들에 비해 높았으며, 암초성 어종이 대부분을 차지하였지만 낮과 밤 간에 우점종은 차이가 있었다. 결과적으로, 거문도 해 역의 높은 어류 풍도는 암반초와 같은 물리적 구조물과 관련이 있었으며, 이는 암반초지역이 많은 어류에게 주요 서식처의 하나가 될 수 있음을 시사하는 것이다.