• ALGAE
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• v.36 no.3
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• pp.175-193
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• 2021

This study provides the first report of the presence of Coolia malayensis in the Mediterranean Sea, co-occurring with C. monotis. Isolated strains from the Gulf of Gabès, Tunisia (South-eastern Mediterranean) were identified by morphological characterization and phylogenetic analysis. Examination by light and scanning electron microscopy revealed no significant morphological differences between the Tunisian isolates and other geographically distant strains of C. monotis and C. malayensis. Phylogenetic trees based on ITS1-5.8S-ITS2 and D1-D3/28S rDNA sequences showed that C. monotis strains clustered with others from the Mediterranean and Atlantic whereas the C. malayensis isolate branched with isolates from the Pacific and the Atlantic, therefore revealing no geographical trend among C. monotis and C. malayensis populations. Ultrastructural analyses by transmission electron microscopy revealed the presence of numerous vesicles containing spirally coiled fibers in both C. malayensis and C. monotis cells, which we speculate to be involved in mucus production.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.3
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• pp.374-384
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• 1999

Benthic marine algal flora and community structure of Yongho-dong area in Pusan, Korea were investigated seasonally in intertidal and subtidal zones by a quadrat method along 5 transect lines from July 1996 to April 1997. In this area, a total of 99 species including 3 blue-green, 13 green, 26 brown and 57 red algae was found. Among them, 33 taxa, together with dominant Ulva pertusa and Corallina pilulifera, occurred throughout the year. Enteromorpha spp. and Ulva spp. vertically distributed in upper and middle zone, while Simphyocladia latiuscula, Chondria crassicaulis, Corallina pilulifera and Sargassum sup. in lower zones. Biomass per unit area exhibited a wide range of variation, from 1,241 g/$m^2$(spring) to 1,648 g/$m^2$(summer) in fresh weight. Maximum and minimum species diversity were recorded in spring and autumn, respectively. Results of the UPGAM cluster analysis suggest that the examined 5 sites can be divided into two groups, sites exposed to open sea (transects 1, 2, 3) and comparatively sheltered sites (transects 4, 5) faced with the Pusan Harbor. The former group is represented by large brown algae, Sargassum and Hizikia, while Ulva pertusa and Lomentaria species are mainly found in the latter group. A calcareous alga, Corallina pilulifera occurred dominantly in both groups throughout the year. In conclusion, number of species in this area was remarkably reduced as compared to the previous data. This result may suggest probably more change of algal vegetation in future, considering the physical and chemical pollutions loaded in the coastal marine environment of this area.

• ALGAE
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• v.33 no.4
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• pp.291-304
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• 2018

Lyngbya C. Agardh ex Gomont is a nonheterocytous cyanobacterial genus whose evolutionary history is still poorly known. The traditionally defined Lyngbya has been demonstrated to be polyphyletic, including at least five distinct clades, some of which have been proposed as new genera. Intraspecific diversity is also clearly underestimated in Lyngbya due to the lack of unique morphological characters to differentiate species. In this study, we describe the new genus Capillus T. A. Caires, C. L. Sant'Anna et J. M. C. Nunes from benthic marine environments, including two new Brazilian species (here described as C. salinus T. A. Caires, C. L. Sant'Anna et J. M. C. Nunes, and C. tropicalis T. A. Caires, C. L. Sant'Anna et J. M. C. Nunes), and two species yet to be described, one of them from India (Capillus sp. 2.1), and the other from United States of America, based on strain PCC 7419. Capillus species presented cross-wise diagonal fragmentation, assisted or not by necridic cells, which has not been previously mentioned for Lyngbya. Ultrastructural analyses showed that C. salinus and C. tropicalis have numerous gas vesicles, which are rarely described for benthic marine species. The new genus formed a well-supported clade, and the D1-D1' and Box B secondary structures of internal transcribed spacer also supported the proposal of its new species. These findings help to clarify the diversity of species in the Lyngbya complex and the taxonomy of the group, and highlight the need of further floristic surveys in tropical coastal environments, which remain poorly studied.

• ALGAE
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• v.33 no.4
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• pp.359-366
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• 2018

Mesocosm experiments conducted for ecological purposes have become increasingly popular because they can provide a holistic understanding of the biological complexities associated with natural systems. This paper describes a new outdoor mesocosm designed for $CO_2$ perturbation experiments of benthos. Manipulated the carbonate chemistry in a continuous flow-through system can be parallelized with diurnal changes, while irradiance, temperature, and nutrients can vary according to the local environment. A target hydrogen ion activity (pH) of seawater was sufficiently stabilized and maintained within 4 h after dilution, which was initiated by the ratio of $CO_2$-saturated seawater to ambient seawater. Specifically, pH and $CO_2$ partial pressure ($pCO_2$) levels gradually varied from 8.05-7.28 and $375-2,691{\mu}atm$, respectively, over a range of dilution ratios. This mesocosm can successfully manipulate the pH and $pCO_2$ of seawater, and it demonstrates suitability for ocean acidification experiments on benthic communities.

• Ocean and Polar Research
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• v.23 no.4
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• pp.347-360
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• 2001

This study examined the taxonomic composition of marine benthic algal flora from Maxwell Bay, King George Island, Antarctica, collected between January 1988 and January 1995. The rhodophyte specimens collected and examined included a total of 20 genera and 20 species of red algae. Of these, 2 species, Kallymenia antarctica Hariot and Pantoneura plocamioides Kylin, were recorded in Maxwell Bay for the first time. Taxonomic keys for the rhodophytes are also provided.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.1
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• pp.273-283
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• 2015

This study was carried out to examine the species composition and community structure of benthic marine algae at the subtidal zones of Daepo, Wolpyeong, Wimi and Jigwido in south Jeju, Korea from March to December 2009. Total 87 species including 14 green algae, 23 brown algae, and 50 red algae were collected and identified. Among these species, 9 species were found throughout the year. The dominant species which contributed significantly to the total biomass were Ecklonia cava, Undaria pinnatifida, Peyssonnelia capensis, Cladophora wrightiana, Sargassum serratifolium, Grateloupia angusta, Codium coactum, Plocamium cartilagineum, and Sargassum macrocarpum. The average seaweed biomass was 7,578.2 g wet weight $m^{-2}$ and maximum biomass was recorded seasonally in spring ($9,627.6g\;m^{-2}$), while minimum was recorded in autumn ($5,963.0g\;m^{-2}$), by sites maximum biomass Jigwido ($12,889.9g\;m^{-2}$), while minimum was recorded in Daepo ($5,403.8g\;m^{-2}$). The seasonal and regional flora were investigated as six functional groups. A coarsely branched form was the most dominant functional group constituting from 42.9~52.8% of the total flora. Ecological state group (ESG) II, as an opportunistic species, including sheet form, filamentous form, and coarsely branched form, consisted of 31~59 species, constituting 77.5~84.9%.

• Korean Journal of Environment and Ecology
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• v.28 no.1
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• pp.10-23
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• 2014

This study was carried out to examine seaweed community structure and distribution of crustose coralline algae at the intertidal and subtidal zones of Gallam, Samchuk, eastern coast of Korea. Total 112 species including 14 of green algae, 33 of brown algae, and 65 of red algae were collected and identified. Among these species, 29 species were found throughout the year. The dominant species which contributed significantly to the total biomass were Ulva pertusa, Colpomenia spp., Sargassum fulvellum, Sargassum fusiforme, Sargassum muticum, Sargassum thunbergii, Corallina pilulifera, and Gelidium elegans. Annual seaweed biomass in dry weight was 66.7 $gm^{-2}$ and maximum biomass was recorded seasonally in summer (107.5 $gm^{-2}$), while minimum was recorded in autumn (36.2 $gm^{-2}$). In seaweed functional group analyses, coarsely branched form was the most dominant functional group constituting from 40.0 to 48.6% of the total flora. Ecological state group ESG II, as an opportunistic species, including sheet form, filamentous form, and coarsely branched form, consisted of 46~61 species, constituting 76.7~82.4%. Crustose coralline algae was observed throughout all seasons. Species of the crustose coralline algae were largely classified into Lithothamnion lemoineae, Lithophyllum okamurai, Lithophyllum yessoense, and Hydrolithon gardineri. The coverage of crustose coralline algae seems to be lower than that of other studies from 36.8% to 11% on average.

• Journal of Plant Biology
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• v.34 no.2
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• pp.165-173
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• 1991

Subtidal algal communities of lnchon Dock, an enclosed artificial dock in the western coast of Korea, were investigated qualitatively and quntitatively. Assessments of species composition, biomass rlominant species, and vertical distribution were conducted from January to December, 1990. Duf"16 the study, benthic marine algal community was disturbed completely by water blooming in June, and was recolonized from July. Forty-five species of marine algae, 18 blue green. 13 green. 6 brown, and 8 red algae, were identified as results. Mean biomass was in ranges of $53.50-118.00\;g-dry\;wt/m^2$ in community before disturbance and $0.57-2.62\;g-dry\;wt/m^2$ after it. Dominant species determined by biomass and frequency were Polysiphonia m0\ulcorner7owii and Ceramium fastigiramosum before disturbance, while Lyngbya semiplena, Lyngbya lutea and Lyngbya rivulariarum after disturbance as pioneer colonizers.nizers.

• Journal of the Korean Magnetic Resonance Society
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• v.28 no.3
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• pp.25-31
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• 2024

Toxins produced by marine toxigenic algae have garnered growing attention due to their detrimental impacts on marine ecosystem, aquaculture, and human health. Among these, diarrhetic shellfish poisoning (DSP) toxins, such as okadaic acid (OA), are of particular concern. In this study, we report the successful isolation and structural elucidation of three new derivatives of OA from the marine dinoflagellate Prorocentrum lima. These newly identified compounds, OA-2Me-C7, OA-2-Me-C8, and OA-1-Me-C8, were characterized through a comprehensive series of NMR experiments, combined with structural comparisons to the well-known OA. The identification of these derivatives contributes to the expanding knowledge of DSP toxin diversity and provides new insights into the structural variations of these harmful algal toxins.

• ALGAE
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• v.34 no.4
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• pp.303-313
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• 2019

Floating seaweed rafts are a surface-pelagic habitat that serve as substrates for benthic flora and fauna. Since 2008, Sargassum horneri clumps have periodically invaded the Korea Strait. In this study, the polymerase chain reaction-free small-organelles enriched metagenomics method was adopted to identify the species of epibiotic eukaryotes present in floating S. horneri fronds. A total of 185 species were identified, of which about 63% were previously undetected or unreported in Korean waters. The rafts harbored a diverse assemblage of eukaryotic species, including 39 Alveolata, 4 Archaeplastida, 95 Opisthokonts, 4 Rhizaria, and 43 Stramenopiles. Of these 185 taxa, 48 species were found at both Sargassum rafts collection stations and included 24 Stramenopiles, 17 Alveolata, and 7 Opisthokonts. Among these, the highest proportion (50%) of species was photo-autotrophic in basic trophic modes, while the proportion of phagotrophic, osmo- or saprotrophic, and parasitic modes were 43.8%, 4.2%, and 2.1%, respectively. This study demonstrates the contribution of floating Sargassum rafts as dispersal vectors that facilitate the spread of alien species.