• Ocean and Polar Research
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• 제23권3호
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• pp.255-264
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• 2001

Development process of benthic community on experimental substrata attached on a newly installed artificial reef complex in Jeju Island was observed for 27 months from 1992 to 1994. Among 34 species of algae and 64 species of zoobenthos obtained from the study, Ecklonia cava dominated with a maximum biomass of about $10kg/m^2$. It was able to smother the other animals, however it provided a new substrate for the new settlers. Opportunistic bryzoans such as Likenopora radiata and Dexiospira spirillum occurred during the early stage were substituted by poriferans, banacles and other bryzoans. Young barnacles were smothered by bryozoans, on the contrary, bryozoans were bulldozed by adult barnacles. No apparent differences have been observed between vertically and horizontally installed substrates in terms of species composition and biomass during the early stage of succession. Thereafter owing to the rapid growth of E. cava, the horizontal substrata carried on a higher biomass while the vertical showed a higher coverage. The benthic process on the experimental substrata can be classified into three stages: initial stage, build up stage and regulatory stage. Important mechanisms involved were canopying of E. cava, suffocation by bryozoans and poriferans, and bulldozing of adult barnacles.

• 수산해양교육연구
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• 제26권5호
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• pp.1037-1043
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• 2014

We extensively observed macroalgal assemblages of species composition and biomass of summer benthic marine algae at Dokdo in the East sea of Korea. A total of 102 species (12 Chlorophyta, 36 Phaeophyta, and 54 Rhodophyta) were identified in quadrats and were analysed qualitatively to define the variation patterns. Biomass in dry weight according to various depths ranged between 146.0 to 764.2 g m-2 at study sites. Mean biomass at the investigated sites was greater in the 10m depth range than in the 5 and 15m depths at Dongdo. The flora could be classified into six functional groups: coarsely branched form (51.0%), filamentous form (17.7%), thick leather form (15.7%), sheet form (5.9%), jointed calcareous form (4.9%) and crustose form (4.9%). The R/P, C/P and (R+C)/P value were 1.67, 0.50 and 2.17, respectively. The number of marine algae species and the biomass in Dokdo area were markedly reduced as compared with those in the previous studies. This result suggests possible future changes in the algal vegetation, considering coastal marine environment of this area.

• 환경생물
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• 제30권1호
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• pp.71-76
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• 2012

Spills of $M/V$ Hebei Spirit on $7^{th}$ December 2007 caused a seriously damage to the ecosystem of Korean coast. Of these, microbial communities (i.e., attached benthic micro-algae) were reported to be sentive to the environmental change so it can be used for ecological risk assessment. Our experiment was designed to examine the ecological risk assessments for oil pollutant using benthic attached algal community on the artificial substrates of acrylic plates. Field monitoring in the culture system was conducted in Jangmok Bay. The abundances of attached micro-algae on artificial substrates gradually increased with increasing of sampling times. Among them, diatoms were the most important colonizer of coastal water, with the genera $Cylindrotheca$ and $Navicular$ most abundant. In particular, developed the culture system has correctly measured qualitative and quantitative abundance of attached micro-algae because same acrylic plates as artificial substrates were used. Thus, this culture system may be directly applied to the ecological risk experiments of microbial community structure from oil pollutants.

• ALGAE
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• 제36권4호
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• pp.241-261
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• 2021

Amphidinium species are amongst the most abundant benthic dinoflagellates in marine intertidal sandy ecosystems. Some of them produce a variety of bioactive compounds that have both harmful effects and pharmaceutical potential. In this study, Amphidinium cells were isolated from intertidal sand collected from the East China Sea. The two strains established were subjected to detailed examination by light, and scanning and transmission electron microscopy. The vegetative cells had a minute, irregular, and triangular-shaped epicone deflected to the left, thus fitting the description of Amphidinium sensu stricto. These strains are distinguished from other Amphidinium species by combination characteristics: (1) longitudinal flagellum inserted in the lower third of the cell; (2) icicle-shaped scales, 276 ± 17 nm in length, on the cell body surface; (3) asymmetrical hypocone with the left side longer than the right; and (4) presence of immotile cells. Therefore, they are described here as Amphidinium stirisquamtum sp. nov. The molecular tree inferred from small subunit rRNA, large subunit rRNA, and internal transcribed spacer-5.8S sequences revealed that A. stirisquamtum is grouped together with the type species of Amphidinium, A. operculatum, in a fully supported clade, but is distantly related to other Amphidinium species bearing body scale. Live A.stirisquamtum cells greatly affected the survival of rotifers and brine shrimp, their primary grazers, making them more susceptible to predation by the higher tropic level consumers in the food web. This will increase the risk of introducing toxicity, and consequently, the bioaccumulation of toxins through marine food webs.

• ALGAE
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• 제21권4호
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• pp.453-461
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• 2006

This study is intended to clarify the structure and seasonal dynamics of warm tolerant benthic marine algal community in Korea. The species composition and biomass of marine algae at the discharge canal of Wolseong nuclear power plant on the East Coast of Korea were investigated seasonally from February 2001 to October 2005. As a result, 43 species (6 blue-green, 8 green, 9 brown and 20 red algae) of marine algae were found at the discharge canal during the past five years. In general, the number of species observed was abundant during winter to summer and less in autumn. Lyngbya confervoides and Enteromorpha compressa always occurred at the discharge canal during the past five years, and Oscillatoria brevis, Padina arborescens and Caulacanthus ustulatus were common species found more than 80% frequency during the study period. Seasonal fluctuations of mean biomass were 2-659 g dry wt m–2 and dominant species in biomass were Caulacanthus ustulatus (contribution to a total biomass proportion 37%), Enteromorpha compressa (26%) and Padina arborescens (24%). Results showed that, in the floristic composition, the green algae occurred as common algal group at the discharge canal of Wolseong nuclear power plant. In the quantitative aspect, however, the red algae such as Caulacanthus ustulatus and Ahnfeltiopsis flabelliformis appeared as predominant group at the discharge canal, in contrast to Kori nuclear power plant where there was a definite green algal dominance. Differences in algal communities developed at the discharge canals of three nuclear power plants on the East Coast of Korea can probably be related to local environmental factors.

• 해양환경안전학회지
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• 제21권2호
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• pp.119-129
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• 2015

우리나라 동해안 중부의 축산항 지역에서 2007년 7월부터 2009년 5월까지 계절별로 조간대와 조하대 해조류의 종조성과 군집구조를 조사하였다. 2년에 걸친 조사를 통해 밝혀진 해조류는 총 98종(녹조류 13종, 갈조류 23종, 홍조류 62종)이었고, 조사시기별로는 33~63종의 범위로 나타났다. 이 가운데 녹조류 2종(구멍갈파래, 떡청각), 갈조류 3종(참그물바탕말, 톳, 왜모자반), 그리고 홍조류 11종(작은구슬산호말, 혹돌잎, 참도박, 참지누아리, 붉은까막살, 진분홍딱지, 진두발, 잔금분홍잎, 개서실, 모로우붉은실, 참보라색우무)의 16종은 모든 조사시기에 관찰되었다. 해조류의 단위면적당 생물량은 평균 $629.68g\;dry\;wt\;m^{-2}$이었으며, 계절별로 $119.30{\sim}1,660.96g\;dry\;wt\;m^{-2}$의 범위를 보였다. 조사지역 해조군집의 수직분포는 조간대에서 작은구슬산호말과 모자반류, 조하대 1 m에서 모자반류, 5 m에서 모자반류와 무절산호조류 그리고 10 m에서 무절산호조류로 대표되었다.

• 한국수산과학회지
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• 제30권4호
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• pp.574-584
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• 1997

남해안 신지도 주변 해조군집의 종조성과 군집 구조 분석을 통하여 이 지역 해조 군집의 특성을 구명하고자 하였다. 이 연구에서 출현한 종은 총 120종으로 녹조류 15종, 갈조류 31종, 홍조류 74종이었다. 이들중 87종이 강독에서 그리고 104종이 동고리에서 출현하였다. 조간대 식생은 크게 3그룹으로 구분되며, 대표적인 종들로는 상부에서 Enteromorpha compressa, Ulva Pertusa, Porphyra suborbiculata, Ishige okamurae, 중부에서는 Hizikra fusiformis, Sargassum thunbergii, Gigartina intermedia, Corallina pilulifera, 하부에는 Pachymeniopsis elliptica, Gelidium amansii, Sargassum homeri 등이 분포하였다. 중요도 값이 높게 나타난 종은 Ulva pertusa, Ishige ekamurae, Hizikia fuisformis, Sargassum thunbergii, Corallina pilulifera, Gelidium amansii, Gigartina tenella로 조사지점 모두에서 공통적으로 나타났다. 기능형군별 분석에서 나타난 비율은 직립분기형 $36.7\%$, 사상형 $27.5\%$, 엽상형 $15.8\%$, 다육질형 $10.0\%$, 유절산호말형 $5.0\%$, 각상형 $5.0\%$로 나타났다.

• ALGAE
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• 제25권3호
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• pp.133-140
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• 2010

Using chlorophyll fluorescence, the vertical migration of benthic diatoms responding to light intensity and affected by sediment grain size was studied. Minimal fluorescence ($F_o$) of surface sediment was measured by imaging pulse amplitude modulated (Imaging-PAM) fluorometer, and used to monitor diatom biomass variation in surface sediments. The test diatoms, Amphora coffeaeformis (C. Agardh) K$\ddot{u}$tzing and Cylindrotheca closterium (Ehrenberg) Reimann & Lewin, migrated to the sediment surface under irradiance from 50 to 500 ${\mu}mol$ photons $m^{-2}s^{-1}$. However, the diatoms exhibited no evident increase of surface biomass under dark conditions, and even showed slightly decrease of surface biomass under irradiances over 1,000 ${\mu}mol$ photons $m^{-2}s^{-1}$. The light intensity inducing the maximum surface migration of A. coffeaeformis was 100 ${\mu}mol$ photons $m^{-2}s^{-1}$, while the light intensity producing the same effect for C. closterium was 250 ${\mu}mol$ photons $m^{-2}s^{-1}$. C. closterium showed higher motility than A. coffeaeformis. Faster diatom surfacing was observed in larger grain size sediments (125-335 ${\mu}m$) than smaller ones (63-125 ${\mu}m$). This study confirmed the significant influence of light as a main triggering factor behind migration, indicated the distinct effect of different sediment grain size, and highlighted the species-specific migratory ability.

• ALGAE
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• 제24권2호
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• pp.111-120
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• 2009

Choosing an appropriate sample unit is a fundamental decision in the design of ecological studies. While numer-ous methods have been developed to estimate organism abundance, they differ in cost, accuracy and precision.Using both field data and computer simulation modeling, we evaluated the costs and benefits associated with twomethods commonly used to sample benthic organisms in temperatc kelp forests. One of these methods, theTargeted Sampling method, relies on different sample units, each "targeted" for a specific species or group ofspecies while the other method relies on coefficients that represent ranges of bottom cover obtained from visual esti-mates within standardized sample units. Both the field data and the computer simulations suggest that both meth-ods yield remarkably similar estimates of organisnm abundance and among-site variability, although the Coefficientmethod slightly underestimates variability armong sample units when abundances are low. In contrast, the twomethods differ considerably in the effort needed to sample these communities; the Targeted Sampling requiresmore time and twice the persormel to complete. We conclude that the Coeffident Sampling metliod may be bettcrfor environmental monitoring programs where changes in mean abundance are of central conccm and resources arelimiting, but that the Targeted sampling methods may be better for ecological studies where quantitative reIation-ships among species and small-scale variability in abundance are of central concern.

• ALGAE
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• 제26권4호
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• pp.317-325
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• 2011

Five benthic species of the genus Gambierdiscus (Dinophyceae) were observed for the first time in the coastal waters of Pakistan, Northern Indian Ocean. The morphology of the epiphytic, ciguatera-related toxic species G. toxicus, G. belizeanus, G. polynesiensis, G. australes and G. cf. yasumotoi are presented here, described by the Kofoid system of thecal plates Po, 3', 7", 6c, 8s, 5"', 1p, 2"" with differences in cell shape, cell size, plates, pores around the apical pore plate by using light and scanning electron microscopy. The occurrence of these potentially toxic dinoflagellate species in Pakistani coastal areas of Manora Channel and Balochistan during high temperatures of 28-$32^{\circ}C$ is cause of concern for human health impacts from ciguatera fish poisoning.