• Journal of Plant Biology
• /
• v.23 no.2
• /
• pp.61-67
• /
• 1980

As a part of the environmental base line survey of the Onsan Industrial Base, Korea, marine algal communities were investigated using the quadrat method in Onsan-myon on the east coast of Korea from March to December of 1978. It was learned that the representative dominat species along the coast in the Onsan area throughout the year are Ulva pertusa, Pachymeniopsis elliptica, and Sargassum thunbergii. Both the number of algal species occurring in the quadrat (50$\times$50cm) and the total coverage were higher in March and September than in June and December. A total of 94 species (1 blue-green, 16 green, 25 brown, and 52 red algae) of marine algae was identified in this study.

• ALGAE
• /
• v.33 no.3
• /
• pp.205-214
• /
• 2018

Red algae in the genus Portieria produce secondary halogenated monoterpenes, which are effective deterrents against herbivores, as secondary metabolites. Portieria hornemannii samples from various sites contain different concentrations of these metabolites, suggesting the existence of genetic diversity and cryptic species. To evaluate the genetic diversity and species distribution of Portieria in the northwest Pacific, we analyzed rbcL sequences of samples collected from Korea, Japan, and Taiwan. The phylogenetic analysis revealed five distinct lineages at the species level. One was recognized as Portieria japonica and the others were cryptic lineages in P. hornemannii. The rbcL haplotypes of P. japonica were genetically fragmented into two subgroups of geographic origin; Korean and Japanese. The four cryptic lineages within P. hornemannii were also geographically structured at a much finer scale. These results suggest that different genetic lineages in Portieria evolved from variable microhabitats, consequently influencing secondary metabolites. Further study is required to resolve the relationships between genetic and secondary metabolite variations in Portieria.

• Journal of Plant Biology
• /
• v.23 no.1
• /
• pp.3-10
• /
• 1980

Effects of thermal effluents on the marine algal communities were investigated with the quadrat method during June, 1977-December, 1978, at the intertidal zone of Kori Nuclear Power Plant, Southeast Coast of Korea. As a result, both the number of algal species occurred in quadrat (50$\times$50cm) and the total coverage were observed to be decreased in June, 1978, at three sites near the discharge point compared with those of previous year but being recovered afterwards. The representative dominant species at the coast of Kori Nuclear Power Plant were, on the whole, Corallina pilulifera, Pachymeniopsis elliptica, and Chondrus ocellatus. Among the species, the coverage of Corallina pilulifera appeared to be rather increased, while the vegetation of Chondria crassicaulis was found to be decreased particularly in 1978. Total 102 species (3 blue-green, 16 green, 30 brown, and 53 red algae) of marine algae were identified in this study. Among them 71 species were common to 133 species reported by previous investigators during 1969-1970.

• ALGAE
• /
• v.36 no.4
• /
• pp.327-332
• /
• 2021

Raw material of gelidioid red algae yielding high-quality agar has been in short supply due to overharvesting, but in situ farming of gelidioids has not been practical due to their slow growth. To produce vegetative seedstock of a cosmopolitan species, Pterocladiella capillacea, we investigated the number and length of regenerated branches arising from sectioned fragments during 3 weeks of laboratory culture at 10, 15, 20, and 25℃. All sectioned fragments formed axis-like branches mostly from the upper cut edge and stolon-like branches mostly from the lower cut edge, showing a high capacity of regeneration and intrinsic bipolarity. At 20℃, the number of regenerated branches increased to 2.74 ± 1.29 on the upper cut edge and 4.26 ± 2.66 on the lower cut edge. Our study reveals that the use of fragments bearing regenerated branches as seedstock can be a simple method to initiate fast propagation for mass cultivation in the sea or outdoor tank.

• Journal of Microbiology
• /
• v.45 no.6
• /
• pp.541-546
• /
• 2007

Red algae are distributed globally, and the group contains several commercially important species. Griffithsia okiensis is one of the most extensively studied red algal species. In this study, we conducted expressed sequence tag (ESTs) analysis and synonymous codon usage analysis using cultured G. okiensis samples. A total of 1,104 cDNA clones were sequenced using a cDNA library made from samples collected from Dolsan Island, on the southern coast of Korea. The clustering analysis of these sequences allowed for the identification of 1,048 unigene clusters consisting of 36 consensus and 1,012 singleton sequences. BLASTX searches generated 532 significant hits (E-value <$10^{-4}$) and via further Gene Ontology analysis, we constructed a functional classification of 434 unigenes. Our codon usage analysis showed that unigene clusters with more than three ESTs had higher GC contents (76.5%) at the third position of the codons than the singletons. Also, the majority of the optimal codons of G. okiensis and Chondrus crispus belonging to Bangiophycidae were G-ending, whereas those of Porphyra yezoensis belonging to Florideophycidae were G-ending. An orthologous gene search for the P. yezoensis EST database resulted in the identification of 39 unigenes commonly expressed in two rhodophytes, which have putative functions for structural proteins, protein degradation, signal transduction, stress response, and physiological processes. Although experiments have been conducted on a limited scale, this study provides a material basis for the development of microarrays useful for gene expression studies, as well as useful information for the comparative genomic analysis of red algae.

• ALGAE
• /
• v.32 no.4
• /
• pp.309-324
• /
• 2017

Recently, the heterotrophic nanoflagellate Katablepharis japonica has been reported to feed on diverse red-tide species and contribute to the decline of red tides. However, if there are effective predators feeding on K. japonica, its effect on red tide dynamics may be reduced. To investigate potential effective protist predators of K. japonica, feeding by the engulfment-feeding heterotrophic dinoflagellates (HTDs) Oxyrrhis marina, Gyrodinium dominans, Gyrodinium moestrupii, Polykrikos kofoidii, and Noctiluca scintillans, the peduncle-feeding HTDs Luciella masanensis and Pfiesteria piscicida, the pallium-feeding HTD Oblea rotunda, and the naked ciliates Strombidium sp. (approximately $20{\mu}m$ in cell length), Pelagostrobilidium sp., and Miamiensis sp. on K. japonica was explored. We found that none of these heterotrophic protists fed on actively swimming cells of K. japonica. However, O. marina, G. dominans, L. masanensis, and P. piscicida were able to feed on heat-killed K. japonica. Thus, actively swimming behavior of K. japonica may affect feeding by these heterotrophic protists on K. japonica. To the contrary, K. japonica was able to feed on O. marina, P. kofoidii, O. rotunda, Miamiensis sp., Pelagostrobilidium sp., and Strombidium sp. However, the specific growth rates of O. marina did not differ significantly among nine different K. japonica concentrations. Thus, K. japonica may not affect growth of O. marina. Our findings suggest that the effect of predation by heterotrophic protists on K. japonica might be negligible, and thus, the effect of grazing by K. japonica on populations of red-tide species may not be reduced by mortality due to predation by protists.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2004.05a
• /
• pp.279-284
• /
• 2004

Red tide(harmful algae) in the Korean Coastal Waters has a given a great damage to the fishery every year. However, the aim of our study understands the influence of meteorological factors (air and water tempaerature, precipitation, sunshine, solar radiation, winds) relating to the mechanism of red tide occurrence and monitors red tide by satellite remote sensing, and analyzes the potential area for red tide occurrence by GIS. The meteorological factors have directly influenced on red tide formation. Thus, We want to predict and apply to red tide formation from statistical analyses on the relationships between red tide formation and meteorological factors. In future, it should be realized the near real time monitoring for red tide by the development of remote sensing technique and the construction of integrated model by the red tide information management system (the data base of red tide - meteorological informations).

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.48 no.5
• /
• pp.39-45
• /
• 2011

There have been many studies on red tide because of increasing of damage to sea farming by a red tide blooms of harmful algae. The studies of red tide have mostly focused chemical properties and investigation of biological cause. If we can predict the occurrence of red tide, we will be able to minimize the damage of red tide. However, internal study of prediction of red tide blooms is only classification method that is still insufficient for red tide blooms forecast. In this paper, we proposed the red tide blooms prediction method using neural network and SVM.

• Journal of Korean Society of Environmental Engineers
• /
• v.34 no.11
• /
• pp.780-785
• /
• 2012

Existing states of attached algae in the sedimentation basin was observed during late april to early october, and the attached algae were visible 7 days after of cleaning the trough and the communities of algae became larger with increasing the operation periods. Attached algae community included bluegreen algae (Oscillatoria sp.), diatom (Synedra sp.,) and green algae (Mougeotia sp., Oedogonium sp.) and suspended diatom (Stephanodiscus sp.) as well. Diatom (Cymbella sp., Navicula sp., Synedra sp. and Stephanodiscus sp.), green algae(Mougeotia sp. and Cosmarium sp.) and blue-green algae (Anabaena sp.) were detected in the effluent of sedimentation basin. The chlorophyll-a (chl-a)concentrations of algae community on a square centimeter after 14 and 28 days were distinctively different depended on the copper sulphate treatment. The concentration of chl-a were $4{\mu}g/L/cm^2$ and $19{\mu}g/L/cm^2$ for the copper sulphate treated water and $59{\mu}g/L/cm^2$ and $147{\mu}g/L/cm^2$ for the untreated water. Diatom algae fragments were observed in red-brownish sediments on the bottom of industrial water distribution basin and degraded blue-green and green algae formated organic sediments combined with oxidized iron.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.42 no.6
• /
• pp.664-673
• /
• 2009

An intertidal marine benthic algal vegetation and vertical distribution at Youngil Bay, the eastern coast of Korea was investigated to clarify the community structure and vertical distribution by quadrat method from February 2003 to January 2009. Marine algae identified from the area were 152 species; 25 green, 38 brown and 89 red algae. The dominant species were Ulva spp., Ulva pertusa, Chaetomorpha moniligera, Undaria pinnatifida, Sargassum horneri, S. miyabei, S. thunbergii, Gelidium amansii, Corallina pilulifera, Grateloupia elliptica, G. filicina, Prionitis cornea, Chondrus ocellatus, Chondracanthus intermedia, Acrosorium polyneurum, Chondria crassicaulis, Polysiphonia morrowii and Symphyocladia latiuscula at study sites. The vertical distribution of intertidal marine algae was divided into three distinct zones. They were characterized by Porphyra spp. and Ulva spp. at the upper, Ulva spp. and Ulva pertusa at the middle, and Sargassum spp., Gelidium amansii, Grateloupia spp., Chondrus ocellatus and Chondria crassicaulis at the lower zones, respectively. Functional form group analysis showed that coarsely branched forms comprised 44.7% of the algal community, whereas thick leathery forms, sheet forms and filamentous forms comprised 6.6-25.7%. R/P, C/P and (R+C)/P values were 2.34, 0.66 and 3.00, respectively.