• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.368-378
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• 1983

The community structure of intertidal benthic marine algae were studied seasonally at Odongdo, southern coast of Korea, from June 1982 to May 1983. Algal coverage in $50{\times}50\;cm$ quadrat were recorded for each species by line transect method. The vertical zonation investigated by line transects is recognized into three groups : Upper, middle, and lower zones. The representative species are Gelidium divaricatum, Enteromorpha linza, Porphyra yezoensis, Scytosiphon lomentaria, Blidingia nana, Ectocarpus confervoides in the upper, Ulva pertusa, Chondria crassicaulis in the middle, and Sargassum sagamianum, S. thunbergii, Undaria pinnatifida, Gelidium amansii and various other red algae in the lower zone. The number of algal species and coverage were generally highest in April and lowest in August. Species which appear dominant at least once a year were all of the spring type and the others were autumn type. According to the cluster analysis by similarity index community coefficient(SICC) among 5 transects, the algal communities are divided into two groups, i. e. open-sea group and inland-sea group.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.1
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• pp.64-70
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• 2002

The marine algal flora and community structure of Gahakri in Jindo Gun, southern coast of Korea, was investigated monthly during September, 1993-August, 1994. As the results, a total of 87 species including 11 greens, 15 browns and 61 reds was identified. The marine algal flora was classified as the mixed flora based on the species composition. The dominant species of algal community throughout the year was Gloiopeltis furcata, and the subdominants were Sargassum thunbegii, Ulva pertusa and Hizikia fusiformis. In their vertical distribution, the species of algal community distributed yearly (or seasonally) from upper to lower intertidal zones were Gloiopeltis furcata-Corallina pilulifera, Myelophycus simplex, Gloiopeltis tenax (May$\~$October), Dumontia simplex, Sargassum thunbergii-Hizikia fusifomis, Ulva pertusa, Chondracanthus intemedius, Carpopeltis affinis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.5
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• pp.768-775
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• 2015

Seasonal variability in the marine seaweed community structure was examined in the intertidal zones at nine study sites in Hallyeohaesang National Park, on the southern coast of Korea from March to October 2014. A total of 145 seaweeds were indentified, comprising 15 green, 41 brown and 89 red algae. Coarsely branched seaweeds were the dominant functional group, comprising 58.95% in species number, whereas filamentous, sheet, thick leathery, crustose and jointed calcareous forms comprised 2.63-17.72% each. The seaweed biomass averaged 358.00 g dry wt/m² and it was maximal at Somaemuldo (847.64 g dry wt/m²) and minimal at Gamam (56.51 g dry wt/m²). Based on biomass, the dominant and subdominant seaweeds were Ulva australis at Gamam, Sargassum thunbergii at Sangju, Ulva australis and S.fulvellum at Neukdo, S.horneri at Dala-Bijindo-Somaemuldo, S. thunbergii at Dapo, and Corallina pilulifera at Songdo. Community indices were as follows: dominance index (DI), 0.43-0.71; richness index (R), 8.26-16.50; evenness index (J'), 0.36-0.54; and diversity index (H'), 1.57-2.19. In conclusion, we found that both biomass and the community structure of seaweeds in Hallyeohaesang National Park were similar to those in other studies of the Southern Sea along the Korean peninsula, and that Hallyeohaesang National Park is a relatively favorable habitat for seaweeds. Future studies should examine the changes in seaweed composition and biomass as they relate to climate change and environmental pollution.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.3
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• pp.385-392
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• 2016

Seasonal variability in the algal community structure of intertidal zones was examined at six study sites in Marine National Parks, on the western and southern coasts of Korea from March to November 2015. A total of 193 species of algae, comprising 27 green, 40 brown and 126 red algae, were identified. Algal biomass averaged 101.50 g dry wt./m² with a maximal at Tonggae (168.12 g dry wt./m²) and minimum at Haseom (54.49 g dry wt./m²). The dominant seaweeds by biomass were Sargassum thunbergii at five sites (Tonggae, Haseom, Namdongri, Ando amd Sinjeonri), and S. fusiforme at Soando. Community indices measured as follows: dominance index (DI), 0.31–0.69; richness index (R), 7.30–11.43; evenness index (J'), 0.33–0.49; and diversity index (H'), 1.15–1.86. As evaluated using community indices and environmental states, the EEI (Ecological Evaluation Index) of the Marine National Park was “normal”. The present results indicate that seaweed community structures and indices could be used to evaluate the environmental status of coastal ecosystems.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.1
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• pp.55-64
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• 2017

Seasonal variability in algal community structure was examined at the intertidal zones of five study sites on the Taean Peninsula, on the western coast of Korea, from February 2014 to November 2015. A total of 118 species of marine algae, comprising 17 green, 24 brown and 77 red algae, were identified. The maximum number of species was observed at the Mohang site (75 species), and the minimum at the Yeonpo site (46 species). The seaweed biomass was $160.24g\;dry\;wt./m^2$ on average, and was maximal at Uihang ($519.04g\;dry\;wt./m^2$) and minimal at Yeonpo ($19.03g\;dry\;wt./m^2$). Based on biomass, the dominant seaweeds at Taean peninsula were Sargassum thunbergii and Corallina pilulifera. Community indices were as follows: richness index (R), 3.21-5.01; evenness index (J'), 0.33-0.38; and diversity index (H'), 0.90-1.12. Based on evaluation of the environmental states by the community indices, the ecological evaluation index (EEI) of Taean peninsula was "moderate". The overall species and biomass of seaweeds decreased after the oil spill. However, Hakampo previously showed a similar algal community structure. In conclusion, the algal community was temporarily affected by the oil spill, but rapidly recovered.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.3
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• pp.316-324
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• 1995

Ecology and life History of the mudskipper, Boieophthaimus pectinirostris were investigated based on the specimens collected from the Korean roasts from 1978 to 1994. The spawning of this species takes place during the period from June to August. Prolarva hatched from egg was 3.3mm in total length, and began to bottom life in TL 16.0mm of 40 days after hatching. The stomach contents were principally diatoms. In the foraging behavior, this species were conducted at the wet soft mud on the upper tidal zones. The burrowing observed in the intertidal mud flat was YL type. B. pectinirostris is restricted to western and southwestern coast of Korea, but their habitats and individuals are being reduced by the result of reclimation to tide land.

• Journal of Environmental Impact Assessment
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• v.19 no.6
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• pp.563-571
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• 2010

In carrying out the prior review on environmental conditions for basic plan of public waters reclamation, the important item is review on conditions of location on prearranged reclaimed land. In this study, environmental assessment which needs careful consideration in the first stage of selecting location is presented by analyzing environmental impact assessment on public waters reclamation projects for about 10 years. The assessment index for alternative comparison is divided into two parts according to importance level. What is most important in alternative comparison is the comparison on direct influence due to reclamation. In other words, it figures out damaged extent of natural shoreline as well as intertidal and infralittoral zones. Comparing influence extent due to reclamation through the 1st comparison on this is regarded as to be important. In case there is no significant difference by alternatives through the 1st assessment, the 2nd assessment should be carried out. In the 2nd assessment indexes are damaged quantity of benthic organism, change in seawater current, erosion, accumulation and exchangeable rate of seawater. The plan for selecting optimal location which minimizes environmental influence in establishing public waters reclamation plan is demonstrated through model cases. For this, 3 districts which have similar environment and scale are selected, and then comparison on location alternative is made through environmental assessment index. In addition, the comparison on 3 arrangement alternatives are conducted, targeting certain areas. It is thought that carrying out comparison review on respective areas in the same cities and counties, not merely comparing arrangement plan by selecting 1 targeting area in advance, is the most appropriate. Besides, selection of arrangement plan considering environment, which minimizes damage of natural shoreline and influence due to change of seawater current is required in alternative comparison on arrangement plan as well. In case of the prior review on environmental conditions though alternative comparison method presented in this study is carried out, it is safely said that the influence on ocean environment due to public waters reclamation can be minimized.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.5
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• pp.19-27
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• 2015

The results of Saemangeum seadike field inspection and material testing of armor stones in order to analyze causes of abrasion according to material characteristics of seaside armor stones in Saemangeum seadike are in the following: 1. The armor stones in Saemangeum seadike have been constructed by using internal stones (mainly, sinsi stones) and external stones, which had less strength (77.3 %) and more abrasion rate (133.3 %) compared with sinsi stones. 2. The compressive strength and abrasion rate were compared between ordinary wave section and high wave section for the purpose of analyzing the influence of waves. In compressive strength, sinsi stones were 4.0 % stronger and external stones were 0.6 % stronger in ordinary wave section than those of high wave section in average. In the case of abrasion rate, sinsi stones were 3.0 % higher and external stones were 8.2 % higher in the high wave section than those in the ordinary section. 3. The result of comparing compressive strength according to a zone is that the compressive strength in the Intertidal area was less strong in most of the zones. 4. Considering that deviated stones are moving around over the surface of armor stones in situ, it is important to compare material characteristics. So the comparison test about this factor showed that deviated sinsi stones were stronger than armor stones in situ in terms of compressive strength and resistance to abrasion. Based on these results, abraded armor stones may have resulted from their durability. Therefore it is assumed that armor stones are likely to be abraded when deviated stones which are more durable are moving around over armor stones which are less durable.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.927-934
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• 2014

Marine algal flora and community structure were seasonally examined at Jungjado, on the southern coast of Korea, from July 2007 to May 2008. A total of 112 seaweeds, including 15 green, 24 brown, and 73 red algae, were identified and 33 species were found throughout the year. The average seaweed biomass was 145.78 g dry weight $m^{-2}$, and the biomass was maximal in winter (184.74 g) and minimal in autumn (106.17 g). The dominant and subdominant species in terms of biomass were Sargassum thunbergii and Grateloupia elliptica in summer, S. thunbergii and Corallina pilulifera in autumn, S. thunbergii and Chondracanthus intermedius in winter, and Sargassum fusiforme and G. elliptica in spring. The vertical distribution patterns of seaweeds from the upper to lower intertidal zones at Jungjado were S. thunbergii - Ulva conglobata - Gelidium elegans in summer; Caulacantus ustulatus - Chondria crassicaulis - C. pilulifera in autumn; Ulva australis - S. thunbergii - G. elliptica in winter; and Gloiopeltis tenax - S. fusiforme - G. elliptica in spring. Seasonally the evenness, richness, and diversity indices tended to have their highest values during the winter and their lowest values in the summer. However, the dominant index was recorded as lowest in winter and highest in the summer. The C/P, R/P, and (R+C)/P values reflecting the flora characteristics were 0.58, 3.04, and 3.62, respectively.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.1
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• pp.43-52
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• 2015

The growth and population dynamics of eelgrass (Zostera marina) due to changes in sediment composition were examined in the lower intertidal zone of the Seomjin Estuary, Korea. We surveyed environmental factors such as water temperature, underwater irradiance, main types and organic content of sediment, tidal exposure, and nutrient concentrations in the water column and sediment pore water, in relation to the shoot density, biomass, morphological characteristics, and growth of Z. marina inhabiting lower intertidal zones. The survey was conducted monthly from May to December of 2004 and 2009. The water temperature showed obvious seasonal trends in both study years. Underwater irradiance was significantly higher in 2009 than in 2004. Tidal exposure was not significantly different between 2004 and 2009. The sediment was muddy-sand in 2004 but became sandy and with a significantly lower organic content in 2009. Water column $NH_4{^+}$ concentrations were significantly higher in 2004 than in 2009. Sediment pore water $NO_3{^-}+NO_2{^-}$ concentrations were significantly higher in 2009 than in 2004. Other nutrient concentrations did not differ significantly between 2004 and 2009. Morphological characteristics, including eelgrass length and leaf width were significantly lower in 2009 than in 2004. Eelgrass shoot height, leaf length, and sheath length showed typical seasonal patterns, increasing in early summer and decreasing in autumn, in both years. Vegetative shoot density was not significantly different between 2004 and 2009, while the biomass of individual plant parts and the total biomass were significantly lower in 2009. Eelgrass leaf productivity did not differ between years, but leaf turnover time was significantly shorter in 2009 than in 2004. Eelgrass downsizing and decreased turnover time in 2009 compared to 2004 indicate more effective adaptations to the stress of long-term changes in sediment composition. Overall, results suggest that changes in sediment composition can be a limiting factor for seagrass growth in the intertidal zone.