• Ocean and Polar Research
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• 제43권1호
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• pp.31-43
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• 2021

To understand the temporal variation of prokaryotic communities in a temperate coastal area, prokaryotic abundance, activity, and community composition were investigated every week for over a year at a coastal monitoring station of Yeong-do, Busan. The prokaryotic abundances fluctuated about 10 times, ranging from 2.0 to 20.1 × 10⁵ cells mL^-1 and tended to be high in spring when phytoplankton bloom occurred. The prokaryotic thymidine incorporation rates (TTI) varied in a low range between 0.2 and 11.5 pmol L^-1 h^-1 in winter. However, in summer, TTI were increased up to a range of 8.3 to 17.4 pmol L^-1 h^-1, showing an increasing pattern in summer. During the study period, Alphaproteobacteria was the most dominant class for most of the year, followed by Flavobacteria. While the seasonal variation of prokaryotic composition was not apparent at the class level, many prokaryotic species showed a distinct temporal or seasonal variation for the year. In the coastal site, prokaryotic biomass and activity did not show significant correlations with temperature and chlorophyll-a, which are well known to regulate prokaryotic growth in marine environments, suggesting that the study area may be affected by diverse sources of organic matter for their growth.

• Ocean Science Journal
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• 제41권4호
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• pp.315-318
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• 2006

Three Synechococcus strains were isolated from seawater near the Ieodo Ocean Research Station (IORS), and their 16S rDNA genes and the internal transcribed spacer (ITS) between the 16S and 23S rRNA genes were sequenced to investigate their phylogenetic relationships. Phylogenetic trees based on the 16S rDNA and ITS sequences showed that they clustered in the main MC-A Synechococcus group (subcluster 5.1), but formed branches differentiating them from the described clades. As the IORS is located in an area affected by diverse water masses, high Synechococcus diversity is expected in the area. Therefore, the IORS might be a good site to study the diversity, physiology, and distribution of the Synechococcus group.

• Animal Systematics, Evolution and Diversity
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• 제38권4호
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• pp.205-213
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• 2022

A new free-living marine nematode, Chaetonema longicorpus sp. nov., was discovered in a subtidal benthic habitat around the Uljin nuclear power plant in the East Sea. Chaetonema longicorpus sp. nov. differs from other Chaetonema species in its very long body length, relatively long cephalic setae, long and narrow buccal cavity, bottle-shaped amphideal fovea, short spicules, only one pre-cloacal seta instead of a pre-cloacal supplement, and conspicuous ventral swelling at the middle of the tail. Herein, we provide a taxonomic description and illustrations of this new species using differential interference contrast microscopy. Furthermore, an illustrated pictorial key to all valid species, including the new species and comparative tables on the biogeographical and morphological characteristics of the genus Chaetonema, are provided.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2003년도 춘계 수산관련학회 공동학술대회발표요지집
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• pp.279-280
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• 2003

Although it has been known though many morphological and physiological studies, its genetic diversity and population structure have not yet been investigated in this species. Therefore, detailed studies, in particular at the DNA level, on genetic diversity of natural populations of wild sea lettuce, and genetic relationships between natural sea lettuce and cultivated sea lettuce are necessary from the viewpoint of plant evolution. (omitted)

• 한국해양학회지:바다
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• 제19권2호
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• pp.147-154
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• 2014

해양 환경에서 세균은 다양한 생지화학적 순환에 있어서 중요한 역할을 수행하고 있으며, 그들의 다양성에 대한 정보는 생태계에서 세균의 생지화학적 기능을 이해하는데 중요하다. 본 연구는 $CO_2$ 해양지중저장의 후보지인 동해 남부해역의 표층 퇴적물과 퇴적물 위의 저층 해수에서 최신 연구 기법인 pyrosequencing을 통하여 세균의 계절적 다양성을 분석함으로써, 동해 퇴적물 세균상의 특성을 이해하고자 하였다. 퇴적물에서는 대부분의 시기에 Gammaproteobacteria가 우점한 반면, 저층 해수에서는 Alphaproteobacteria가 우점하여 두 서식처에서 세균의 다양성은 큰 차이를 보였다. 또한 속 수준의 다양성 분석에서도 저층 해수에서는 대부분의 시기에 SAR11 그룹에 속하는 Pelagibacter가 가장 우점한 반면, 퇴적물 시료에서는 Gammaproteobacteria에 속하는 미동정 속이 가장 우점하였다. 그러나 두 서식처 모두에서 5% 이상의 점유율을 보인 속의 수는 10 속 미만으로 소수였으며, 낮은 점유율을 갖는 많은 종류의 세균들이 군집 내에 공존하는 공통적인 특성이 나타났다. 본 연구의 세균 다양성 연구는 동해 저층 해수 및 퇴적물의 세균 다양성에 대한 특성의 이해와 더불어 $CO_2$ 해양지중저장 사업의 진행에 따른 세균의 다양성 및 기능 변화에 대한 사전 자료 및 해역이용영향평가 배경 자료로 활용될 수 있을 것이다.

• Journal of Species Research
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• 제9권3호
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• pp.191-197
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• 2020

Species belonging to the genus Tryblionella are important members of the diatom assemblages of benthic environments such as tidal flats. Their proper identification is thus of great importance in terms of taxonomy, ecology, as well as environmental sciences. However, many species of the genus have been neglected and/or misidentified during diatom studies of Korean tidal flats possibly due to the small size of the species. Lack of proper references for the identification of the species is also noted. To better understand the diversity of Tryblionella species, sediment samples were taken from various tidal flats of the Yellow Sea. Light microscope (LM) and scanning electron microscope (SEM) observations have shown the presence of Tryblionella adducta and T. hyalina, which have not been previously reported from Korean tidal flats. The former was found mostly from sand flats and the latter from mudflats. It is expected that the present study would contribute to a better understanding of the diversity and ecology of benthic diatoms of the Korean tidal flats.

• Ocean and Polar Research
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• 제42권4호
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• pp.271-281
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• 2020

We investigated mesozooplankton in the Yellow Sea in spring to understand its community structure and relationship with environmental factors. Total mesozooplankton density ranged from 1,542 to 7,367 ind. m-3 and the biomass ranged from 3 to 42 mg C m-3. The total density and biomass had a positive relationship with chlorophyll-a (chl-a) concentration. The mesozooplankton community was divided into two groups at 125.5 E by cluster analysis: one was an inshore group and the other was an offshore group. The inshore group of mesozooplankton was of high density but low diversity, while the offshore group was of high diversity but low density. Copepod Acartia hongi and its copepodites were the most abundant species, comprising 27.8% of the total mesozooplankton density. A. hongi was especially abundant at the inshore, serving as the indicator species of the inshore group. Redundancy analysis found a positive relationship between the density of A. hongi and chl-a concentration. Oithona similis and Centropages abdominalis were 2nd and 3rd dominant species comprising 9 and 7% of the total density, respectively. The density of O. similis was positively related to water depth, but C. abdominalis was related to chl-a concentration. Chl-a concentration seems to influence significantly the mesozooplankton community structure in the Yellow Sea in spring, rather than water temperature or salinity.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2002년도 춘계 수산관련학회 공둥학술발표회
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• pp.263-264
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• 2002

• ALGAE
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• 제31권3호
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• pp.231-241
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• 2016

We examined the genetic diversity and abundance of picocyanobacteria using barcoded amplicon sequencing approaches and flow cytometry in the East Sea and the East China Sea to determine the distribution patterns of diversity during spring in seas adjacent to the Korean Peninsula. Synechococcus clades I and IV, which have been known as cold-adapted ecotypes, dominated at most stations. However, the relative abundances of the two dominant clades differed in their spatial patterns. Clade I was exclusively dominant in the shelf area of the East China Sea and the north East Sea. However, the dominant genotypes belonging to clade I had different spatial distributions in the two areas and responded oppositely to seawater temperature. The dominance of distinct genotypes under the different ecological conditions suggests the presence of ecologically different ecotypes within the clade. Abundances of clade IV were greater than those of clade I at most stations in the southwest East Sea, showing an apparently different pattern from that of the other areas. A warm-water adapted clade II was observed at significant levels only at stations located in the eastern East China Sea affected by a branch of the warm Kuroshio Current. These results suggest that the physicochemical properties of influencing water masses play an important role in determining the distribution of Synechococcus genotypes.

• 한국수산과학회지
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• 제46권1호
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• pp.1-9
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• 2013

Fisheries' biological resources were considered public resources before the 1990s. Every country could access and use these resources without regulation. However, the United Nations adopted the Convention on Biological Diversity and the privileges and rights to these resources were attributed to countries. This research starts with the research background and social and academic value of "The Jasan Eobo (or Report on Marine Organisms in the Coastal Waters near Heuksan Island)" by Jeong Yak-Jeon, who pioneered the new field of Fisheries Science and Marine Biology in Korea in the early 1800s. We also searched for recent results from the Marine Bio-Diversity Research Activities of the Korean National Council for Conservation of Nature (KNCCN) and the Ministry of Maritime Affairs and Fisheries (MOMAF). KNCCN reported that marine bio-diversity comprised approximately 6,500 species in 1996, and the Ministry of Maritime Affairs and Fisheries reported there were about 10,000 species in 2007. Among these marine species, plankton account for about 25%, seaweeds 11%, invertebrates 52%, and vertebrates 12% in Korean Coastal Areas. The Ministry for Food, Agriculture, Forestry, and Fisheries (MIFAFF) enacted a law for Agriculture and Fisheries Resources Management in 2012; this law includes the preservation of marine ecosystems, the conservation of wetlands and the preservation of fisheries resources, and describes the boundary of taxonomy for new species and unknown species that could be identified in the near future. To follow the new regulation for Access to General Resources and Benefit-Sharing, this research suggests (1) the importance of taxonomy for new species and unknown species as a goal of "No Name = No Information", (2) integrated research on bio-diversity, species distributions and the abundance of fisheries resources, both in local areas and in Korean Coastal Areas, and (3) the observance of international regulations or agreements for benefit-sharing without additional damage in the future.