• 제목/요약/키워드: coastal waters

검색결과 1,513건 처리시간 0.023초

Morphology and distribution of some marine diatoms, family Rhizosoleniaceae, genus Rhizosolenia, in Korean coastal waters

  • Yun, Suk-Min;Lee, Sang-Deuk;Lee, Jin-Hwan
    • ALGAE
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    • 제26권2호
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    • pp.141-152
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    • 2011
  • The present study describes the morphology, taxonomy, and distribution of species belonging to the diatom genus Rhizosolenia in Korea's marine coastal waters. From September 2008 to February 2010, we collected phytoplankton samples at 30 sites along the Korean coastline and studied them by light and scanning electron microscopy. We found 6 rhizosolenid genera in our samples: Rhizosolenia, Dactyliosolen, Guinardia, Pseudosolenia, Proboscia, and Neocalyptrella. In the present paper, we studied the following rhizosolenid species and compared them with congeners: R. pungens, R. fallax, R. imbricata, Rhizosolenia sp. 1, and Rhizosolenia sp. 2. The morphology of R. pungens exhibits important diagnostic characteristics in its girdle segment structure in the column and in its external process. To distinguish R. fallax and R. imbricata, the most important characteristics are the striation and the velum structure. R. pungens occurred in our samples all along the Korean coast. Only rarely did we find R. imbricata in the samples and at low abundance. We recorded R. fallax, Rhizosolenia sp. 1 and Rhizosolenia sp. 2 for the first time in Korean waters, but they rarely occurred.

연안 혼탁 해수에 적합한 위성 클로로필-a 농도 산출 알고리즘 개관과 전망 (Overview and Prospective of Satellite Chlorophyll-a Concentration Retrieval Algorithms Suitable for Coastal Turbid Sea Waters)

  • 박지은;박경애;이지현
    • 한국지구과학회지
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    • 제42권3호
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    • pp.247-263
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    • 2021
  • 최근의 기후변화는 연안에서 더욱 가속화되고 있어 연안에서의 해양 환경변화 감시의 중요성이 커지고 있다. 클로로필-a 농도는 해양 환경 변화의 중요한 지표 중 하나로 수십년 동안 여러 해색 위성을 통해 전구 해양 표층의 클로로필-a 농도가 산출되었으며 다양한 연구 분야에 활용되었다. 하지만 연안 해역의 탁한 해수는 외해의 맑은 해수와는 구별되는 구성 성분과 광학적 특성으로 인해 나타나는 심각한 오차 때문에 일반적으로 사용되는 전지구 대양을 위하여 만들어진 클로로필-a 농도 알고리즘은 연안 해역에 대입할 수 없다. 또한 연안 해역은 해역에 따라 성분과 특성이 크게 달라져 통일된 하나의 알고리즘을 제시하기 어렵다. 이러한 문제점을 극복하기 위하여 연안의 탁도가 높은 해역에서는 구성 성분과 광학적 변동 특성을 고려한 다양한 알고리즘들이 개발되어 사용되어 왔다. 클로로필-a 농도 산출 알고리즘은 크게 경험적 알고리즘, 반해석적 알고리즘, 기계학습을 활용한 알고리즘 등으로 나눌 수 있다. 해수의 반사 스펙트럼에 기반한 청색-녹색 밴드 비율이 기본적인 형태로 주로 사용된다. 반면 탁한 해수를 위해 개발된 알고리즘은 연안해역에 존재하는 용존 유기물과 부유물의 영향을 상쇄시키기 위한 방식으로 녹색-적색 밴드 비율, 적색-근적외 밴드 비율, 고유한 광학적 특성 등을 사용한다. 탁한 해수에서의 신뢰성 있는 위성 클로로필-a 농도 산출은 미래의 연안 해역을 관리하고 연안 생태 변화를 감시하는데 필수적이다. 따라서 본 연구는 탁도가 높은 Case 2 해수에서 활용되어온 알고리즘들을 요약하고, 한반도 주변해역의 모니터링과 연구에 대한 문제점을 제시한다. 또한 다분광 및 초분광 센서의 개발로 더욱 정확하고 다양한 해색 환경을 이해할 수 있는 미래의 해색 위성에 대한 발전 전망도 제시한다.

Estimation of the Efficiency of a Silt Screen using a Vessel-mounted ADCP

  • Jin, Jae-Youll;Park, Jin-Soon;Song, Won-Oh;Kim, Sung-En;Lee, Kwang-Soo;Yum, Ki-Dai;Oh, Jae-Kyung
    • 한국해안해양공학회:학술대회논문집
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    • 한국해안해양공학회 2003년도 한국해안해양공학발표논문집
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    • pp.353-358
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    • 2003
  • As fur quantitative evaluation of the amount of sediments released into the ambient waters by various works fur coastal development, the instrument and method of the measurement of suspended sediment concentration (SSC) are critical for estimating the efficiency of a silt screen to reduce the spreading of sediment plumes generated by coastal works. (omitted)

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Spatial-temporal distributions of the newly described mixotrophic dinoflagellate Gymnodinium smaydae in Korean coastal waters

  • Lee, Sung Yeon;Jeong, Hae Jin;Ok, Jin Hee;Kang, Hee Chang;You, Ji Hyun
    • ALGAE
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    • 제35권3호
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    • pp.225-236
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    • 2020
  • Gymnodinium smaydae is a newly described mixotrophic dinoflagellate that feeds on only Heterocapsa spp. and Scrippsiella acuminata among 19 tested algal prey. It is one of the fastest growing dinoflagellates when feeding, but does not grow well without prey. To investigate its spatial-temporal distributions in Korean waters, we quantified its abundance in water samples that were seasonally collected from 28 stations along the Korean Peninsula from April 2015 to October 2018, using quantitative real-time polymerase chain reactions. This dinoflagellate had a wide distribution, as reflected by the detection of G. smaydae cells at 23 of the sampling stations. However, this distribution had a strong seasonality; it was detected at 21 stations in the summer and only one station in winter. The abundance of G. smaydae was significantly and positively correlated with chlorophyll a concentration as well as with water temperature. However, there were no significant correlations between the abundance of G. smaydae and salinity, concentrations of nutrients, or dissolved oxygen concentration. During the study period, G. smaydae was present when water temperatures were 7.6-28.0℃, salinities were 9.6-34.1, concentrations of NO3 were not detectable-106.0 μM, and concentrations of PO4 were not detectable-3.4 μM. The highest abundance of G. smaydae was 18.5 cells mL-1 in the coastal waters of Jinhae in July 2017 when the chlorophyll a concentration was 127 mg m-3 and water temperature was 23.8℃. Therefore, the spatial-temporal distribution of G. smaydae in Korean coastal waters may be affected by chlorophyll a concentration and water temperature.

Morphology and taxonomy of the planktonic diatom Chaetoceros species (Bacillariophyceae) with special intercalary setae in Korean coastal waters

  • Lee, Sang-Deuk;Lee, Jin-Hwan
    • ALGAE
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    • 제26권2호
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    • pp.153-165
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    • 2011
  • Species of the diatom genus Chaetoceros with special intercalary setae are uncommon. For this study, we collected Chaetoceros species from August 2008 to September 2009 in Korean coastal waters and examined the ultra structures of the Chaetoceros species C. coarctatus, C. compressus var. hirtisetus, C. contortus, C. diversus, and C. messanensis, using light and scanning electron microscopy. C. coarctatus, in the subgenus Phaeoceros, showed longer and stronger spines than those found in other species. C. coarctatus and C. diversus had special intercalary setae with spines in straight arrangements, whereas C. compressus var. hirtisetus, C. contortus, and C. messanensis had special intercalary setae with spines arranged in spirals. The setae of C. coarctatus had spines that were robust toward the tips and, overall, longer and stronger than were those of other species. C. coarctatus and C. diversus were straight, and C. compressus var. hirtisetus, C. contortus, and C. messanensis spiraled. C. messanensis had two types of special intercalary setae, both forked: 1 with spines in spirals and 1 lacking spines. We did not find spines on the anterior part of divergent point of the special intercalary setae of C. messanensis. Foramina shapes of these 5 Chaetoceros species varied as follows: very small or no foramina in C. coarctatus, relatively wide and slightly centrally constricted foramina in C. compressus var. hirtisetus and C. contortus, quite narrowly slitted or no foramina in C. diversus, and lanceolate or hexagonal foramina in C. messanensis. We found rimoportula in both intercalary and terminal valves of C. coarctatus, but C. compressus var. hirtisetus, C. contortus, C. diversus, and C. messanensis only had rimoportula in terminal valves. In addition, C. compressus var. hirtisetus and C. contortus were new to Korean coastal waters.

내만에서의 해수면 후방산란신호 특성 (Characteristics of Surface Backscattering Signal in the Coastal Bay)

  • 최지웅;나정열;조운현
    • 한국음향학회지
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    • 제19권2호
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    • pp.46-53
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    • 2000
  • 내만은 잦은 선박통행, 인공구조물에 의한 쇄파 그리고 생물학적 활동으로 외해에 비해 공기방울의 생성이 활발하다. 따라서 공기방울의 생성과정과 분포형태가 주로 쇄파에 의존하는 외해의 특성과는 매우 다른 내만에서의 해수면 후방산란신호를 분석하였다. 해수면 후방산란신호의 입사각에 따른 변화, 해수면 부근에서의 잔향특성 그리고 산란신호의 주파수 확장폭 등을 외해의 산란신호 특성과 비교하였다. 내만에서의 표층 산란신호는 시간영역에서는 매우 불규칙한 진폭의 변화를 보이고 주파수 확장폭이 외해의 거친 해수면보다 더 크게 나타나고 있다. 소위 해수면 잔향신호의 진폭 분포는 기존에 알려진 Rayleigh 분포를 따르지 않고 있어 공기방울의 크기 및 수직분포가 외해와 비교, 매우 상이한 특성을 갖고 있음을 보여주고 있다.

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봄철의 한국 남해 멸치와 정어리난 분포 및 감소율의 비교 (Comparisons of Egg Distribution and Mortality Rate between Anchovy and Sardine during Spring in the Southern Waters of Korea)

  • 김진영;김주일;최광호
    • 한국수산과학회지
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    • 제27권3호
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    • pp.299-305
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    • 1994
  • 1991년과 1992년의 $3{\sim}4$월에 한국 남해안에서 어난을 채집하여 멸치와 정어리 난 분포역의 변동을 비교하고 발생 단계별 분포밀도로써 감소율을 추정하였다. 멸치와 정어리 난은 1991년 3월과 1992년 3월말${\sim}4$월초에 대마도 남서해역에서 동시에 높은 밀도로 분포하였다. 특히 1992년에는 1991년에 비하여 멸치와 정어리난 분포범위가 남해중부 외해역까지 확장되어 있었다. 조사해역의 표층수온은 $8.6{\sim}17.8^{\circ}C$였으며, 멸치와 정어리 난의 대부분은 $14{\sim}15^{\circ}C$에서 출현하였다. 1991년 3월 $4{\sim}15$일에 있어서 난의 발생단계별 분포밀도로부터 추정된 순간감소계수를 비교하면 멸치는 0.268/일, 정어리는 0.132/일로서 정어리 난 난의 1일 감소율이 멸치에 비하여 낮은 경향을 보였다.

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활멸치의 집약적 생상수단에 관한 연구 -IV (Study on the Intensive Catching method of Anchovy for the Live Bait-IV Appearance of the Available Resource for the Live Bait in the South-eastern Coastal Waters of Korea)

  • 이병기;김광홍
    • 수산해양기술연구
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    • 제15권2호
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    • pp.77-82
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    • 1979
  • 멸치는 남해안에서는 여러 단계의 크기의 것이 혼획되는데, 가다랭이 미끼용으로는 채장 6-7m의 것이 알맞으므로, 이 크기의 것을 가급적 언중 확보하기 위해서는, 그 분포상을 조사하여 적정 자원이 가장 많이 출현하는 해역을 알 필요가 있다. 또, 멸치의 크기에 따라 상품가치도 크게 다르므로 멸치 어업을 합리적으로 운영하기 위해서나, 자원의 관리를 위해서도 채장 조사는 중요하다. 여기서는 멸치어업이 주로 이루어지는 7월부터 12월의 한국 동남 해역에 있어서의 멸치의 분포상에 관하여 조사한 것을 보고한다

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방조제 건설 중인 2001-2002년 새만금 하구역 어류 종조성의 계절 변동 (Seasonal Variation in Species Composition of Fish in the Estuary of Saemangeum Waters during the Construction of a Dike in 2001-2002)

  • 이태원;문형태;김광천
    • 한국수산과학회지
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    • 제36권3호
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    • pp.298-305
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    • 2003
  • Seasonal variation in species composition of fish in the estuary of Saemangeum water in the western coast of Korea was determined using seasonal samples collected by an otter trawl from April 2001 to February 2002. Species compositions did not differ significantly among the 4 stations (p>0.05, Wilcoxon signed-rank test). The cumulative number of species and species diversity (H') approached asymptote after four 30-min trawl hauls. Therefore 30-min trawl samples from each of the four stations were pooled to represent each season. A total of 45 species 2758 individuals and 30,346.8 g of fish were collected during the study period. Of the fish collected Leiognathus nuchalis, Synechogobius hasta, Neosalanx jordani, Konosirus punctatus and Chaeturichthys stigmatias predominated in abundance accounting for $68\%$ of the total number of individuals. Seasonal variation of fish abundance showed a similar trend to those of the other western coastal waters of Korea. The resident species were collected only in spring and autumn. Number of species and biomass were highest in summer due to the catch of many migrating species. In winter catch amount was low, and only 7 species were collected.. Brackish water fishes were more abundant in the study area, and Johnius grypotus and Cynoglossus joyneri were not premominated compared to the other coastal waters. This difference in species compositions may be related to the lower salinity in this estuarine habitat than in the other western coastal waters of Korea.

한국산 놀래기과 어류의 분류학적 검토 (Taxonomical Review of the Korean Labroidei (Teleostei: Perciformes))

  • 김병직
    • 한국어류학회지
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    • 제21권sup1호
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    • pp.74-74
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    • 2009
  • The perciform suborder Labroidei comprising six families (Cichlidae, Embiotocidae, Pomacentridae, Labridae, Odacidae, and Scaridae) are characterized by having the specialized pharyngeal jaws for food processing, i.e., united fifth ceratobranchials and upper pharyngeal jaw articulating with the basicranium via diarthroses (Stiassny and Jensen, 1987). They usually inhabit in the most tropical and subtropical seas and comprise about 235 genera and roughly 2,274 species worldwide (Nelson, 2006). Concerning the Korean labroid fishes, Mori (1952) had listed 18 genera and 26 species belong to four families in his check list of Korean fishes since Jordan and Metz (1913) firstly reported six genera and seven species in only two families (Embiotocidae and Labridae). Chyung (1977) added two species, Tilapia mossambica and Cirrhilabrus temmincki, to Mori’s list and also classified them into three suborders, i.e., Embiotocina (containing only Embiotocidae), Pomacentrina (Cichlidae and Pomacentridae), and Labrina (Labridae and Scaridae). Subsequently, Lee and Kim (1996) reviewed the Korean labroidfishes taxonomically resulting in 22 genera and 32 species in five families with some taxonomical modifications including a new Korean record. It is remarkable to be added many new Korean recordsto the pomacentrids or the labrids for recent 10 years (Koh et al., 1995; Yoo et al., 1995; Koh et al., 1997; Myoung, 1997; Choi and Kim, 2000; Choi et al., 2002; Kim and Go, 2003). Recently, Kim et al. (2005) briefly described all members of the Korean Labroidei with a color photograph or a figure, recognizing 27 genera and 42 species in five families. In the present study, the current taxonomical status of the Korean labroid fishes including distributional features is summarized based both on specimens collected from the Korean waters and on literature survey to provide bio-information of the Korean native fish species. As a result, the Korean labroid fishes totally consist of 27 genera and 44 species in five families, that is, Cichlidae (1 species), Embiotocidae (3), Pomacentridae (15), Labridae (22), and Scaridae (2). They distributed mainly in the coastal waters of the South Sea, Korea, however, most pomacentrids or labrids occur in the coastal waters of Jeju Island only, although some species were observed in their larval or juvenile stages only from coastal waters of the island. Interestingly, several species are expanding their distribution north to Ulreung and Dok islands in the East Sea, Korea lately.