• Journal of Wetlands Research
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• v.7 no.2
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• pp.69-88
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• 2005

Distribution of benthic macrofauna was surveyed in the subtidal area and on the sand flat of Sindu-ri coast during July 2002. A total of 134 species, 3,511 individuals and 388g biomass of macrobenthos were sampled inclusively from the study sites. 109 species with a mean density of $1,298ind./m^2$ and biomass of $69.4g/m^2$ were collected from 10 stations established in the subtidal area. Polychaetes were represented as a dominant faunal group of the subtidal area in both species richness and density with values of 54 species and $813ind./m^2$. Cluster analysis based on the faunal composition showed that the subtidal area could be divided into four stational groups according to sedimentary characteristics: Cirrophorus armatus - Lumbrineris longifolia association on the mud sediment with pebbles near aqua-farms; Aonides oxycephala association on the rocky bed; Scoloplos armiger - Grandifoxus cuspis association on the sand-dominated sediment along the lowest low water; a association with higher evenness on the sand-dominated sediment in the depth. Although having characteristics of high value in species richness, density and species diversity, the macrobenthic association around the farming area was dominated by the opportunistic species such as Lumbrineris longifolia and Tharyx sp. Natural community represented by S. armiger and G. cuspis was developed in most sand-dominated areas. 50 species were sampled with a mean density of $2,443ind./m^2$ and biomass of $381.3g/m^2$ from eight+ stations along two transects on Sindu-ri sand flat. Mollusks were represented as a dominant faunal group of the sand flat in species richness, density and biomass with values of 20 species, $1,345ind./m^2$ and $350.4g/m^2$, respectively. Umbonium thomasi, Veneridae sp., Mandibulophoxus mai, Armandia lanceolata, Eohaustorius spinigerus, Urothoe convexa were dominant species and these species accounted for over 83% of total individuals. There were three distinct zones of macrobenthos on Sindu-ri sand flat according to the extent of exposure time. The upper zone was dominated by Scopimera globosa, the middle zone was characterized by M. mai, and the lower zone was dominated by E. spinigerus. Sindu-ri coastal area was considered as a healthy habitat for macrobenthos, except for around the farming area. It was considered that Sindu-ri coastal area including the sand flat connected to the sand dune of natural monument was a valuable habitat as a protected site in having no pollution source and no artificial structure.

• The Korean Journal of Malacology
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• v.24 no.3
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• pp.199-203
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• 2008

Thirty one marine molluscan species were added to the malacofauna of Dokdo Island, Korea based on the samples collected from April 2006 to August 2008 with SCUBA diving. As a result, one hundred six marine molluscan species were recorded from Dokdo Island hitherto.

• The Korean Journal of Malacology
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• v.20 no.2
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• pp.159-164
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• 2004

In the present study we examined latitudinal trend of the number of species and species diversity of rocky subtidal shelled gastropods. Specimens were sampled from four wave-exposed sites along the eastern coast of Korea between Sockcho (38$^{\circ}$14"N_ and Busan (35$^{\circ}$06"N), covering a range of over ca. 440 km and 4$^{\circ}$ of latitude. At a small local scale, the number of species showed a latitudinal trend, decreased with decreasing of latitude, even though no clear trends in species diversity were detected. The present result, consequently, suggest that regulation of small-scale local diversity presumably results from the difference of the local micro-environment.

• Fisheries and Aquatic Sciences
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• v.13 no.4
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• pp.324-331
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• 2010

Seasonal variation in seaweed biomass was examined along vertical shore gradients on the rocky shores of Nachido and Odo Islands, the Yellow Sea, Korea, from August 2007 to April 2008. The average annual biomass of seaweed was 404.07 g wet wt/$m^2$, with seasonal variation from 232.61 g in the spring to 754.90 g wet wt/$m^2$ in the summer at Nachido Island. At Odo Island, average biomass was 270.82 g wet wt/$m^2$ and ranged from 48.35 g in the winter to 451.66 g wet wt/$m^2$ in the spring. Seaweed biomass exhibited an even distribution across the shore gradient from the high intertidal zone to -5 m depth at Nachido Island, whereas seaweed biomass was concentrated from the mid intertidal zone to -1 m depth in the subtidal zone at Odo Island. Sargassum thunbergii was the most dominant species, occupying 28.24% (114.12 g wet wt/$m^2$) and 36.57% (99.05 g wet wt/$m^2$) of total biomass at Nachido and Odo Islands, respectively. Subdominant seaweed species was Gelidium amansii, comprising 15.23% (61.52 g wet wt/$m^2$) and 14.70% (39.82 g wet wt/$m^2$) of total biomass at Nachido and Odo Islands, respectively. Dominant functional group was the coarsely branched-form group, which grows under moderate environmental conditions and comprised 93.34% (377.15 g wet wt/$m^2$) and 66.96% (181.35-g wet wt/$m^2$) of total biomass at Nachido and Odo Islands, respectively. Percentage biomass of sheet-form seaweeds growing at relatively disturbed and polluted areas was approximately 20.83% (56.40 g wet wt/$m^2$) of total biomass along the Odo rocky shore. Based on the biomass and functional-form composition of seaweeds, we concluded that Nachido Island provides better environmental conditions than does Odo Island. In addition, the vertical distribution and dominant species of seaweeds on the two islands were very similar, but the functional-form composition of seaweeds at Nachido Island differed slightly from that at Odo Island.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.23 no.4
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• pp.192-203
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• 2018

The surfgrass Phyllospadix iwatensis is native in the exposed rocky shores of the Northwestern Pacific Ocean. In Korea, P. iwatensis is mainly found on the rocky subtidal zone in the central eastern coast. In this study, to examine the ecological characteristics of P. iwatensis, we investigated changes in morphological characteristics, density, biomass, and leaf productivity as well as changes in the underwater irradiance and water temperature of its habitat monthly from August 2017 to July 2018. Underwater irradiance and water temperature showed clear seasonal changes; increases in spring and summer and decreases in fall and winter. Morphological characteristics, shoot density, biomass, and leaf productivities of P. iwatensis exhibited significant seasonal variations, increasing in winter and spring and decreasing in summer and fall months. P. iwatensis leaf productivities both per shoot and per unit area showed significant positive correlations with underwater irradiance. The average leaf productivity of P. iwatensis per area was $6.3{\pm}1.3g\;m^{-2}d^{-1}$, while minimum and maximum values were $2.4{\pm}0.3g\;m^{-2}d^{-1}$ in February 2018 and $16.4{\pm}4.4g\;m^{-2}d^{-1}$ in May 2018, respectively. The optimum water temperature for the growth of P. iwatensis in this study was between $12-13^{\circ}C$.

• 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 Environment and Ecology
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• v.27 no.6
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• pp.655-665
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• 2013

This study was carried out to investigate the community structure and biomass of benthic marine algae at the intertidal and subtidal zones of Eocheongdo on the western coast of Korea seasonally from July 2008 to April 2009. Total 101 species including 12 of green algae, 23 of brown algae and 66 of red algae were collected and identified. Among these species, 19 species were found throughout the year. The dominant species which contributed significantly to the total biomass were Corallina pilulifera, Gelidium elegans, Sargassum thunbergii, Sargassum fusiforme, Saccharina japonica, Sargassum honeri and Sargassum filicinum. Annual seaweed biomass in dry weight was $237.5gm^{-2}$ and maximum biomass was recorded seasonally in winter ($272.1gm^{-2}$), while minimum was recorded in summer ($204.5gm^{-2}$). The number of species and biomass of the subtidal zone were greater than those of the intertidal zone. The number of species and biomass in Eocheongdo seem to be higher than those of other islands in the western coast of Korea, due to the environmental conditions characterized by the increased transparency, and the well established rocky shore.

• The Korean Journal of Malacology
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• v.26 no.1
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• pp.19-31
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• 2010

Seogundo is a small island adjacent to the southern coast of Jeju Island and connected to it by a boulder beach at low tide Surveys of this area were conducted from 2001 to 2009 to enumerate the mollusks there and also to examine their diversity, relative abundance, and ecological relationships. Both the boulder beach itself and several large tide pools were studied, including the coarse sand substrate and several species of seaweed and coralline algae found in the tide pools. Of the 121 species obtained or observed, there were 97 gastropods, 16 bivalves, and 8 polyplacophorans. Live specimens were obtained for about half of those species. About one third were found on rocky substrate, with the most common species being Nodilittorina radiata and Nerita japonica in the upper intertidal zone, N. radiata and Littorina brevicula in the middle intertidal, and Turbo (Lunella) coronata coreensis and Acanthopleura japonica in the lower intertidal and shallow subtidal. The seaweeds and coralline algae contained about 40% of all mollusk species. The most common mollusks in two species of brown seaweed were Ittibittum parcum, Musculus nanus, and Euplica scripta. In a species of red seaweed, Komaitrochus pulcher was the most frequent, as in the coralline algae, along with M. nanus. The coarse sand in the tidepools contained about 25% of the species, with the Cerithiidae having the largest number. A sample of beach drift contained 17 species, with Bittium aleutaceum and Rissoina (Phosinella) pura being most common. Most species, about 60%, were found in a variety of habitats, especially the marine flora; few species exhibited any habitat preferences. Biographically, Jeju Island is part of the Warm Temperate Northwest Pacific Province and the East China Sea ecoregion with a strong faunal affinity with southern Japan, eastern China, and northeastern Taiwan. Zonal-geographical groupings reveal that the fauna is mainly subtropical-low boreal, preferring moderately warm water, with a somewhat smaller number of tropical-subtropical species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.5
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• pp.532-539
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• 2010

Seaweed biomass was estimated in the rocky subtidal zone of Daejin on the mid-east coast of Korea using a destructive sampling method from February to November 2007. Monthly sampling was conducted at depths of 5, 10 and 15 m using 50 $\times$ 50 cm quadrats. A total of 73 species, including 5 chlorophytes, 25 phaeophytes, 43 rhodophytes and one seagrass were identified. Average seaweed biomass was 2,852.3 g wet wt. $m^{-2}$ and biomass values varied monthly from 1,189.8 g to 7,523.7 g. The species dominant in biomass were Laminaria japonica (481.7 g), Sargassum confusum (470.85 g), Undaria pinnatifida (422.57 g), Costaria costata (282.16 g), Odonthalia corymbifera (174.46 g), S. sagamianum (163.22 g) and S. horneri (122.18 g). The vertical distribution of algae was characterized by S. confusum and U. pinnatifida at 5 m, L. japonica and U. pinnatifida at 10 m, and O. corymbifera and L. japonica at 15 m depth. The C/P, R/P and (R+C)/P values were 0.20, 1.72 and 1.92, respectively.

• ALGAE
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• v.23 no.4
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• pp.327-334
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• 2008

Seaweed biomass was estimated using a nondestructive sampling method in the rocky intertidal and subtidal zone in Daejin on the mid-east coast of Korea from August 2006 to April 2008. Seasonal sampling were done at the depth of 0, 1, 5, 10 m using 50 x 50 cm quadrat. A total of 95 species, including 11 chlorophytes, 26 phaeophytes, 57 rhodophytes and one sea grass were identified. Mean biomass was comprised of 1,292 g wet wt m$^{-2}$ and the biomass values varied seasonally from 904 g to 1,945 g. Dominant species in biomass were Sargassum spp. (S. horneri, S. yezoense), Corallina pilulifera, Phyllospadix japonica, Symphyocladia latiuscula, Hizikia fusiformis, Codium arabicum and Chondrus ocellatus at Daejin. The vertical distribution of algae were characterized by Corallina pilulifera, Symphyocladia latiuscula, Sargassum spp. (S. confusum, S. yezoense), Hizikia fusiformis and Grateloupia elliptica at intertidal zone, Sargassum spp. (S. fulvellum, S. horneri, S. yezoense), Phyllospadix japonica, Codium arabicum, Undaria pinnatifida and Corallina pilulifera at 1 m depth, Sargassum spp. (S. horneri, S. micracanthum, S. yezoense), Phyllospadix japonica, Grateloupia elliptica, Gelidium amansii and Codium arabicum at 5 m depth and Phyllospadix japonica, Codium arabicum, Sargassum spp. (S. horneri, S. micracanthum, S. yezoense) and Undaria pinnatifida at 10 m depth.