• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.453-462
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• 1998

Macrobenthic community structure was studied at thirteen stations in Taebudo subtidal area, Korea, from July to October 1996. Triple macrobenthos samples were collected using a van Veen grab (0.1 $m^2$) at each station during the study period. A total of 209 species of macrobenthos was sampled with a mean density of 1,093 ind./$m^2$ and biomass of 134,86 g/$m^2$. Of these, there were 72 species of polychaetes ($34.5\%$), 69 crustaceans ($33.0\%$) and 49 molluscs ($23.4\%$). Polyalaetes were represented as a density-dominant faunal group with a mean density of 608 ind./$m^2$, comprising $55.6\%$ of the total benthic animals. It was followed by crustaceans with 307 ind./$m^2$($28.1\%$ of the total density), Echinoderms were represented as a biomass-dominant faunal group with a mean biomass of 54.21 g/$m^2$($40.2\%$ of total biomass). Total number of species and diversity were low in the inner part of the study area with high mud content and high in the offshore stations of mixed sediments. Major dominant species were three polychaetes, Heteromastus filifomis, Scoloplos armiger and Tharyx sp. whose mean densities were 70 ind./$m^2$, 67 ind./$m^2$, and 66 ind./$m^2$, respectively. Cluster analysis showed that the study area could be divided into five stational groups based on the faunal composition, that is, the innermost stations, coastal stations, transitional stations and two offshore station groups. The species diversity of these groups increased from the inner stational group toward the outer groups.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.1
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• pp.67-82
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• 2008

This study was performed to investigate changes in benthic environment and macrobenthic polychaete communities in Gamak Bay where various environmental quality improvement projects have been implemented in recent years. Field surveys were carried out in February, 2005 and February, 2006 and twenty stations were selected to explore whether or not there were between-year differences in biotic and abiotic variables. Of 10 environmental variables measured, only three variables including dissolved oxygen (DO), total ignition loss (IL), acid volatile sulfide (AVS) showed significant between-year differences. Specifically, IL and AVS were, on average, 1.5 and 3 times lower in 2006 compared to those in 2005, respectively, which was more pronounced in the northern part of the bay. A total of 95 polychaete species was sampled from the two sampling occasions. Between-year differences in the number of species, abundance, and diversity were varied from place to place. In the northern part of the bay, fewer species were found in 2006 rather than in 2005, but diversity increased in 2006 due to the reduction in dominance of a few species. On the contrary, in the central part of the bay, the number of species, abundance and diversity prominently increased in 2006. In the southern part of the bay, all the biological indices maintained similarly during the two years. Dominant species in 2005 were such opportunistic or organic pollution indicator species as Lumbrineris longifolia, Capitella capitata, Mediomastus californiensis, Pseudopolydora paucibranchiata, etc. and most of them were mainly distributed in the northern part of the bay and in the proximity of it. In 2006, however, Euchone alicaudata, L. longifolia, Paraprionospio pinnata, Flabelligeridae sp., etc. were dominant and distributed mainly in the central part of the bay. Multivariate analyses showed that the whole polychaete community could be divided into 5 groups reflecting the geographical positions of the sampling stations and temporal variation particularly in the northern part of the bay. According to the results of BIO-ENV procedure, TOC (${\rho}=0.52$) and AVS (${\rho}=0.49$) as a single variable best explained the polychaete community structure. The best combination was made by such variables as TOC, AVS, sorting coefficient, and water temperature (${\rho}=0.60$). In conclusion, between-year differences in biotic and abiotic variables imply that recent efforts for the environmental improvement produced positive influences on the benthic environment of Gamak Bay, particularly the northern part of the bay.

• Korean Journal of Environmental Biology
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• v.23 no.2 s.58
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• pp.106-113
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• 2005

This study was conducted to examine the community structure of macrobenthos on Angel tidal flat in Jinhae, south coast of Korea. Monthly samples were conducted at eight sites from March 1998 to February 1999. A total of 110 species were sampled with a mean density of 322ind. $m^{-2}$ and biomass of 98.4 wwt g $m^{-2}$. Of these species, there were 44 species of polychaetes $(40.0\%)$, 41 species of crustaceans $(37.3\%)$ and 16 species of molluscs $(14.5\%)$. The major density dominant species were a gastropod Batilaria cumingi (52ind. $m^{-2}$) and five polychaetes Ceratonereis erythraeensis (38ind. $m^{-2}$), Cirriformia tentaculata (32ind. $m^{-2}$), Capitella capitata (23ind. $m^{-2}$), Sigambra tentaculata (23ind. $m^{-2}$), Glycera chirori (17ind. $m^{-2}$). Cluster and MDS analysis showed that the study sites could be divided into two tidal elevation groups. According to the spatial distribution of dominant species and SIMPER analysis, the two groups were characterized by Sigambra tentaculata - Chaetozone setosa in upper species group and Ceratonereis erythraeensis-Cirriformia tentaculata-Capitella capitata in lower species group.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.2
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• pp.115-132
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• 1992

This study was conducted to clarify the distribution pattern of macrobenthic soft-bottom dwelling animals near the shellfish farming ground in Chinhae Bay, Korea Sampling was seasonally performed with van Veen grab$(0.1m^2)$ from October 1990 to July 1991. Benthic animals collected during the study comprised 107 species which amounted to 6,978 individuals: 52 species from polychaetes$(48.6\%)$, 34 species from crustaceans$(31.8\%),$ 14 species from molluscs$(13.1\%)$ and 7 species from other faunal groups$(6.5\%)$. The dominant species were four polychaetes and one amphipod: Lumbrineis longifolia, Capitella capitate, Mediomastus sp., Sigambra tentaculata and Erictonius pugnax. The study area could be divided into 3 regions based on the faunal similarity which was closely related to the content of organic matter in the surface sediment. The benthic community located near the shellfish farming ground showed large spatial and seasonal variations in species diversity and evenness in contrast to the stable values off the farming area. The oxygen deficient water mass below 2 ml/l In thi bottom layer during the summer stressed and depauperated the benthic community in the autumn of 1990. However, the benthic community did recover during the winter. It is postulated that the cyclic phenomenon of summer mortality followed by winter recovery may be a common characteristic in benthic communities subjected to a high level of organic pollution.

• The Korean Journal of Malacology
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• v.32 no.4
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• pp.297-328
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• 2016

This study was performed to know and compare the community structures of macrobenthic invertebrates of five fishing grounds in the coastal waters of Jeju Island from 2013 to 2015. A total of 629 species was identified. Molluscans comprised 282 species (44.8%), Arthropods 88 (14.0%), Poriferans 61 (9.7%), Bryozoans 52 (8.3%) and the others including Cnidarians 51 (8.1%). Density and biomass were estimated to be $71,007ind./m^2$ and $599,208.0gwwt/m^2$, respectively. Gastropods was the most dominant taxon in terms of abundance ($24,625ind./m^2$ ) and number of species as well, and Gastropods was predominant in biomass ($190,789.0gwwt/m^2$). The dominant species were Omphalius pfeifferi, Astralium haematragum, Musculus viridulus, Halosydna brevisetosa, Phascolosoma scolops, Herdmania monus in 5-20 m. Based on the cluster analysis, the study area could be divided into five station groups. The biodiversity, evenness and richness index appeared as follows: H' = 4.28-4.64, E' = 0.74-0.79, R = 33.17-35.45. The dominance index were highest in Sagye and lowest in Sinhung.

• Ocean and Polar Research
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• v.33 no.1
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• pp.85-97
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• 2011

The tidal flats of Korea today have reduced by 40% in size compared to 1964. To manage this important habitat properly, development of well-organized and nationwide-applicable grading systems is required. There have been several assessment systems proposed previously in Korea, but they are critically flawed in that selected biological indicators are not adequate and grading criteria are obscure and arbitrary. We reviewed the indicators used in these previous evaluation systems (e.g., diversity indices, quantity and quality of benthic macrofauna, halophytes, water birds, etc.) and subsequently proposed new indicators and an improved grading scheme. For the quantitative assessment of macrobenthic community, biomass reflecting production and ecosystem function is recommended over density, which is much less discriminatory among habitats. Of biodiversity indices used, within-, between-habitat and regional biodiversity indices that accurately reflect sampling efforts are suggested. In addition, we proposed to include species rarity, ecosystem engineers, and the ecological quality index ISEP (Inverse function of Shannon-Wiener Evenness Proportion). As for halophytes, their low spatial coverage on benthic habitat suggests that their presence can be used as an ecological indicator of benthic habitat, regardless of their protective status. We stress the need to introduce 1) quantile approach for quantitative indicators (e.g., diversity, biomass, etc.) in relation to grading, 2) presence-absence approach for spatial or aggregate indicators (e.g., boundaries of halophytes and feeding ground of water birds) and 3) benthic habitat mapping that combines all of these indicators.

• Journal of the korean society of oceanography
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• v.34 no.4
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• pp.220-230
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• 1999

Four tidal flats, covering two dissipative type beaches and two other tidal mud flats, around Yonaiong-Yongyu Islands, Inchon, Korea were studied in May 1991 to analyze the spatial distribution patterns of benthic communities on macrotidal flats. From the statistical test on spatial patterns of species number, density, and biomass, significant trends were found in species number and biomass. Although quantitative analysis was not performed, the interpretation showed that the variations were ruled out by environmental gradients such as sediment grain size and tidal elevation. The eight communities revealed in this study are as follows: Moerella-Mactra(Group 1), llyoplax-Glycera -Magelona japonica-Magelona sp.-Pe riserrula ( Group 2), Amphiura-Nephtys californiensis-Bullacta-Eohaustorius (Group 3), Leonnates-Heteromastus-Pretankyra-Nephtys polybranchia (Group4), Nephtys chemulpoensis-Macrophthalmus (Group 5), Ceratonereis-Scopimera (Group 6), Haustorioides-Urothoe (Group 7) and Cycladicama-Armandia-Minuspio community (Group 8). Some of these communities were classified into substratum-specific (Group 1 to 3) and tidal elevation-specific communities (Group 4). It was difficult to identify the predominant governing agent in Groups 5,6,7 and 8 because of their presence at extreme types of sediment and at uppermost elevations. Mixed effects seemed to act upon the latter four communities (Group 5 to 8). Based on the number of samples, 60% of the target samples were influenced by substratum properties, 20% by tidal elevation effect and 20% by mixed effect of the two factors. From this, it was concluded that substratum properties serve as the most important factors on soft bottom inhabitants in the area studied.

• Journal of the Korean Society for Marine Environment & Energy
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• v.5 no.1
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• pp.68-75
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• 2002

This study were observed to the conditions of organic pollution applying to tile environmental assessments based on macrobenthos around the raft culture ground which became an issue by organic matter input in Jinhae Bay. Three stations, mussel farm, oyster farm and the control station on which rarely culture activities were fixed and have analyzed to the sediment characteristics and macrobenthic communities. Muddy substrates between 6.0 and 6.60 on mean grain size have prevailed to the bottom layer in all stations. The highest organic matter content of 2.8% was observed to the mussel farm while the lowest one of 1.5% was recorded on the control area. As a total, 79 species from seven phyla were identified. Comparing to shell farms, the control station have composed to more diversified community structure. In the mussel and the oyster farm, opportunistic species, living in high organic contents area, Lumbrineris longifolia, Heteromastus. filiformis in polychaetes and Corophium sinense in amphipod were dominated. As results on environmental assessment, in spite of changing to the species composition and densities seasonally, the mussel farm have recorded only to moderately polluted condition.

• 한국해양학회지
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• v.27 no.3
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• pp.197-209
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• 1992

The distribution pattern of macrobenthic polychaete worms and their feeding guild structures were investigated along the coastal region off Kunsan (southeastern Yellow Sea) during the winter season. The polychaete worms, the most dominant infauna, comprised 54 species in 30 families and showed their mean density of 300. indir./m$^2$). Dominant species in the study area were Stermaspis scutata, Lumbrineris cruzensis, Notomastus sp., Nephtys polybranchia, Praxillella affinis. Polychaeres were assigned to 12 feeding guilds and BMX (burrowing, motile, muscular pharynx) was the most dominant feeding guild (26%). Muddy sediments sustained more polychaete worms which showed burrowing (65%), motile (72%), and non-tentaculate strategies (92%), while sandy sediments contained more filter feeders (32%) and sessile (63%), and more tentaculate worms (49%). The sediment grain size was suggested to be the prime factor selecting the polychaete feeding guild.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.3
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• pp.180-189
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• 2001

This study was conducted to investigate the macrobenthic community in Ulsan Bay and Onsan Bay, in November of 1997. The density of benthic animals was 535 md./m2, and the number of species was 117. Polychaeta was the most dominant faunal group, comprising a total of 63 species, and its density was 380 md./m2 The most dominant benthic macrofauna was Cirratulrus cirratulas (2.7%), and followed by Tharyx sp. (16.6%), Ruditapes philippinarum (16.1%), Lumbrineris longifolia (10.3%) and so on. The dominant species occupied their distinct unique distribution area. Tharyx sp., R. philippinarum and Grandidierella sp.1 occurred mainly in Ulsan Bay, L. longifolia and Euchone sp. in Onsan Bay, and C. cirratulas and Cirriforimia tentaculata in both bays. By cluster analysis, study area was divided into 4 station groups: Northern Ulsan Bay (Al), the middle area of Ulsan Bay (Bl), offsea area between Ulsan Bay and Onsan Bay (Bll), and Onsan Bay (C). Northern Ulsan Bay was characterized by low species number and high density. The dominant species were C. cirratulas R. philippinarum and Tharyx sp. The middle area of Ulsan Bay was by low species number and density, and its characteristic species was Grandidierella sp.1. The offsea area between Ulsan and Onsan Bay was by high species number and low density. Onsan Bay was by high species number and high density, and its important species were L. longifolia and Euchone sp.