• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.740-746
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• 2011

Subtidal benthic macroalgal flora and community structure on barren grounds were examined seasonally along vertical shore gradients on the rocky shore of Hajung, Pohang, on the southeast coast of Korea, from February 2005 to November 2006. Twenty-six seaweed species were identified, including 5 green, 7 brown, and 14 red algae. The number of seaweed species ranged between 7 and 17 among seasons and between 13 and 20 species were found in vertical gradients along the shore. Over the study period, average seaweed biomass (g wet wt/$m^2$) was 299.88 g and it ranged seasonally from 120.99 to 620.00 g. Seaweed biomass declined with increasing seawater depth and ranged between 323.06 and 593.68 g. The dominant seaweed species, in terms of biomass, were Desmarestia ligulata and Sargassum honeri, which grew at depths between 5 and 10 m. The red alga Delisea pulchra was also abundant at a depth of 15 m. No seasonal patterns were found in community indices. Along vertical shore gradients, community indices showed different patterns; the dominance index increased and the richness, evenness, and diversity indices decreased with seawater depth.

• Fisheries and Aquatic Sciences
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• v.11 no.3
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• pp.159-165
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• 2008

Intertidal benthic algal communities on the shores of Gujido and Daeyeonpyeongdo islets, Korea, were examined in October 2007. At both sites, 45 seaweeds including 7 green, 6 brown and 32 red algae were identified. The number of species at Gujido(38 species) was 1.5 times higher than at Daeyeonpyeongdo(25 species), but seaweed coverage was very similar with about 20%. Dominant seaweeds in terms of coverage and importance value were Hildenbrandtia sp., Caulacanthus okamurae, Ulva pertusa, and Gelidium amansii at Gujido and U. pertusa, Hildenbrandtia sp., Gelidium divaricatum at Daeyeonpyeongdo. The vertical distribution pattern of the seaweeds was G. divaricatum-U. pertusa, Hildenbrandtia sp.-U. pertusa, Hildenbrandtia sp., Ishige okamurae from upper to lower intertidal zone but seaweed zonations were not observed on the Gujido rocky shore. At both sites, coarsely-branched forms were the dominant functional group in species number and percent cover(among benthic algal species). The rocky shores of the two sites were dominated by crustose coralline and green algae, whose presence generally results in decreased seaweed biodiversity and community stability. Therefore, the shores of the Yeonpyeongdo islets are of considerable environmental concern and should be monitored for seaweed species composition and community structure.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.595-603
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• 2017

The macroalgal community structure was examined at the subtidal zones of six study sites, on the Southern coast of Korea from between May and August 2015. A total of 132 seaweeds, comprising 10 green, 28 brown and 94 red Seaweed, were identified. The seaweed biomass was $80.32g\;dry\;wt.\;m^{-2}$ in average, and it was maximal at Geomundo ($166.94g\;dry\;wt.\;m^{-2}$) and minimal at Byeongpungdo ($14.52g\;dry\;wt.\;m^{-2}$). On the basis of the biomass, the Ecklonia cava was a representative species, distributed widely in the subtidal zone of the three islands (Yeoseodo, Geomundo, Baekdo). Also, the Sargassum sp. was dominant at Sejondo and Hongdo. The turbidity and light transmittance was divided into two groups. The seaweed community structure of group A (Byeongpungdo, Sejondo, Geomundo) was characterized by high turbidity, low light transmittance and a lower habitat depth than were observed in group B (Hongdo, Baekdo, Yeoseodo). As the water depth increased, the biomass decreased due to the lowered light transmittance. In Byeongpungdo and Sejondo, which showed high turbidity and low light transmittance, the degree of seaweed coverage was decreased with the depth of water. The ESGII ratio of the Ecological Status Group was higher than fourty percentage in Byeongpungdo and Baekdo. Community indices were as follows: dominance index (DI) 0.35-0.90, richness index (R) 7.03-17.93, evenness index (J′) 0.22-0.60, and diversity index (H′) 0.79-2.18. The Macroalgal zonation of the subtidal zone was calculated by the Ecklonia cava and Brown algal population on five islands(Byeongpungdo, Yeoseodo, Geomundo, Beakdo, Hongdo). On the other hand, Undaria pinnatifida and Sargassum sp. dominated at Sejondo. Additionally, the biomass ratio and the species richness of green algae was lower in group A. These differences in the seaweed community structure may have resulted from the effects of turbidity and light transmittance.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.1
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• pp.300-307
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• 2015

Seasonal variation in marine macroalgal community structure was examined at the intertidal zones of Geumgap, Jindo, Korea, from October 2013 to August 2014. In total, 56 macroalgal species were identified, including 9 green, 12 brown, and 35 red algae. Annual seaweed biomass was 548.96 g wet wt. /$m^2$ with seasonal range between 371.08 g wet wt. /$m^2$ at summer and 32.91 g wet wt. /$m^2$ at winter. The dominant seaweed in terms of biomass was Sargassum thunbergii and subdominant species were Gelidium elegans, Sargassum fusiforme, and Ishige okamurae. The vertical distribution of seaweeds from the upper to lower intertidal zones was Gloiopeltis spp., Ulva spp.- S. thunbergii, S. fusiforme, Ishige okamurae - S. thunbergii, S. fusiforme, G. elegans. Annual seaweed coverage, richness index (R), evenness index (J'), and diversity index (H') values were 27.95%, 6.10, 0.38, and 1.38, respectively. Coarsely branched form was the most dominant functional group in terms of species number and biomass among benthic macroalgal species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.3
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• pp.262-270
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• 2012

Seaweeds provide habitats in which marine animals can spawn and develop, and serve as a food supply for algaegrazing species such as sea urchins and abalone. Recently, seaweed species have disappeared from coastal ecosystems, leaving barren ground, defined as habitats that have lost their algae forests and where coralline algae containing calcium carbonate components have become encrusted on rocks. The biological causes of barren ground include grazing by herbivores and excessive seaweed harvest. The environmental harm caused by the spread of barren ground includes accelerated eutrophication following the reduction in seaweed, which plays an important role in oceanic purification. In the present study, we identified the relationships between various seaweed species and the occurrence of barren ground. Subtidal benthic macroalgal flora and community structure were observed seasonally on barren ground along vertical transects of rocky shores of Bihwa, Samchuck, and the east coast of Korea from February to November 2006. Fifty-eight seaweed species were identified, including 7 green, 15 brown, and 36 red algae species. There were between 6 and 28 species among seasons. Over the whole study period, average seaweed biomass (g wet wt $m^{-2}$) was 241.90 g, with a seasonal range of 25.26 to 760.34 g. Seaweed biomass declined with increasing seawater depth and ranged between 91.26 and 422.08 g. The vertical distribution of algae was characterized by Undaria pinnatifida and Sargassum honeri at 5 m, S. honeri and U. pinnatifida at 10 m, and U. pinnatifida and Agarum clathratum at 15 m depth. Seasonal patterns in community indices were not found. Community indices showed different patterns along vertical shoreline gradients; the dominance index increased but the richness, evenness, and diversity indices decreased with seawater depth. Sea urchin density was 8 to 24 individ. $m^{-2}$ in Bihwa. These urchin populations had significantly aggregated spatial patterns and recurrent destructive grazing appeared to be occurring.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.878-885
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• 2013

Seasonal variation in marine macroalgal community structure was examined at the intertidal zones of Heuksando and Hongdo, Shinan, Korea, from July 2008 to May 2009. In total, 86 macroalgal species were identified, including 12 green, 19 brown, and 55 red algae; 67 species at Heuksando and 70 species at Hongdo, were observed. Annual seaweed biomass was 252.44 g dry $wt/m^2$ at Heuksando and 217.67 g dry $wt/m^2$ at Hongdo. The dominant seaweed in importance value (IV > 15) differed between the sites: Sargassum thunbergii at Heuksando and Corallina pilulifera at Hongdo. The vertical distribution pattern of seaweeds from the upper to lower intertidal zones at Heuksando was Gloiopeltis spp., Ulva spp. - S. thunbergii, S. fusiforme, Hildenbrandia rubra - S. thunbergii, C. pilulifera. On the rocky shore of Hongdo, seaweed zonation was distinct: Porphyra yezoensis, Gloiopeltis spp., Ulva spp. - C. pilulifera, S. fusiforme, Myelophycus simplex - Chondrus ocellatus, C. pilulifera, and Carpopeltis affinis. Annual seaweed coverage, richness index (R), evenness index (J'), and diversity index (H') values were greater at Hongdo (41.35%, 12.82, 0.59, and 2.50 respectively) than at Heuksando (31.54%, 11.93, 0.44, and 1.87 respectively), which may indicate that the seaweed community at Hongdo is more stable relative to the one at Heuksando.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.1
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• pp.53-60
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• 2016

Seasonal variations in seaweed communities were examined at Gwanmaedo and Yeongsando, Korea, from May 2014 to February 2015. Eighty-nine species were identified, including 11 green, 20 brown and 58 red algae. Seventy-three and 74 species were identified at Gwanmaedo and at Yeongsando, respectively. Sargassum thunbergii and Myelophycus simplex were the dominant species, comprising 60.89 and 39.50% of total biomass, respectively, and S. fusiforme was subdominant at the two sites. Of six functional seaweed forms, the coarsely-branched form was the most dominant, forming about 43% of the species number at Gwanmaedo and Yeongsando. Seasonal seaweed biomasses ranged between 53.10 and 172.85 g/m² (average 93.57 g dry wt./m²) and between 83.11 and 176.20 g (138.21 g/m²) at Gwanmaedo and Yeongsando, respectively. The vertical distribution from the high to low intertidal zone was S. thunbergii and Gloiopeltis furcata; M. simplex and S. thunbergii; and S. fusiforme at Gwanmaedo. Seaweed zonation was distinct at Yeongsando, with S. thunbergii and Gelidiophycus freshwateri; M. simplex and S. thunbergii; and S. thunbergii and S. fusiforme. Seaweed biomass, evenness index (J'), and diversity index (H') values were greater at Yeongsando (138.21 g/m², 0.51, 2.18 respectively) than at Gwanmaedo (93.57 g/m², 0.48, 2.04), indicating that the seaweed community at Yeongsando is more stable than that at Gwanmaedo.

• Korean Journal of Community Nutrition
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• v.15 no.3
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• pp.361-368
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• 2010

This study was carried out to investigate preference and purchase factors of seaweed in some regional residents of Korea. Subjects were residents (n = 1,218) whose residential area was divided into inland and coastal region and the survey was done during December 2007. Especially, purchase factors of seaweeds was conducted only in married females (n = 353). The subjects are composed of 46.5% male and 53.5% female. Regional distribution of subjects was found to be 16~17%, with highest ratio in the age bracket of 20~29 years old. Proportion of students, at 29.8%, was the highest ranking occupation of the subjects. Preference score of seaweeds by region was highest for laver followed by brown seaweed and sea tangle. In terms of preference by gender, female subjects displayed higher preference score for green laver (p < 0.01), seaweed fusiforme, brown seaweed, sea tangle (p < 0.001) than the male subjects. Considerations being made when purchasing seaweeds for each region were in the order of freshness, taste and nutrition. In comparing the inland and coastal region, scores of freshness, convenience, design and color for the coastal region was higher, displaying significant difference.

• Journal of Practical Agriculture & Fisheries Research
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• v.17 no.1
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• pp.45-56
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• 2015

The distribution of seaweed was examined in Jeonnam archipelago marine ranching area, the coastal of geumo-do, Yosu. Abundance and distribution of seaweed in dropping site of artificial reef were sampled at 6 station at October 2007. Seaweed community were investigated with quadrat method at line-transect by scientific SCUBA divers. as a result, 30 species in total, 4 green, 9 brown and 15 red seaweed were identified. Range of seaweed biomass in all sampling stations were about 1,600~4,000 g/m². At intertidal zone, appearance of individuals and dominance rate were showed higher than below the subtidal line and at depth from 4m to 6m, individuals, dominance rate and biomass were represented low level. characteristic of water in marine ranching area is turbidity and also compensation depth is low. For that reason, individuals of seaweed community were smaller from depth of 4 meters. Therefore, when equip the artificial reef for preparation of seaweed beds need consider that equipment periods(early spring; before releasing marine seaweed spore) and suitable water depth(3~6m).

• Journal of Environmental Science International
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• v.21 no.11
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• pp.1407-1418
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• 2012

The purpose of this study is to analyze seasonal variations of seaweed community structure according to ocean environment at three areas in the east coast of Korea. Mean water temperatures of Gosung, Samchuk, and Gyeongju were $8.3^{\circ}C$, $11.2^{\circ}C$, and $13.1^{\circ}C$, respectively, during the growing winter season of 2011. Subtidal benthic macroalgal flora and community structure were investigated at the sites between February to November 2011. The numbers of seaweed species at the areas were 38, 12, and 15, respectively. The amounts of biomass were 7.35 kg $m^{-2}$, 1.80 kg $m^{-2}$, and 0.84 kg $m^{-2}$, respectively, during the period. The values of C/P, R/P, and (R+C)/P representing flora characteristics at Sokcho area were 0.1, 1.1, and 1.2, respectively. The values of flora characteristics at Samchuk were 0.3, 0.6, and 1.0, respectively. The values of flora characteristics at Gyeongju were 0.4, 4.0, and 1.2, respectively.