• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.727-743
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• 1996

To know the floristic composition, vortical distribution and community structure of marine benthic algae inhabiting in the intertidal and subtidal zones of Yongil Bay, east coast of Korea, the study has performed using the quadrat method along a transect line from July, 1995 to June, 1996. In this area, a total of 144 species including 2 new red algae to Korea was found: 5 blue-green, 18 green, 20 brown and 101 red algae. The representative species throughout the year were Ulva pertusa, Gelidium amansii and Symphyocladia latiuscula. Dominant species were Sargassum thunbergii in spring, U. pertusa in summer and autumn. In winter, Chondrus ocellatus and Monostroma grevillei occurred dominantly. The standing crop exhibited mean value as $185.8g/m^2$ dry weight. Maximum value was recorded in spring $(267.3g/m^2)$ and minimum was observed in winter $(93.7g/m^2)$. Shannon's species diversity (H') and evenness (J') as maximum value were recorded in spring, whereas minimum values were shown in winter. Vertical distribution, rerognized by cluster analysis based on relative coverage of the species, could be divided into two or three algal groups except spring. In general, green algae (M. grevillei, Capsosiphon fulvescens, U. pefusa, Enteromorpha compressa) and brown algae (Sargassum fulvellum, S. thunbergii) were represented in the upper and middle zone and red algae (G. amansii, C. ocellatus, S. latiuscula, Crateloupia okamurae, Pachymeniopsis eilliptica) in the lower zone. The algal community varied according to season and environmental conditions. Particularly, seasonal variation of vortical distribution seemed to be affected primarily by water temperature. Also seasonal tidal level and tolerance of algal species to desiccation appeared to be associated with it in this area.

• Korean Journal of Environmental Biology
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• v.37 no.3
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• pp.406-425
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• 2019

To observe the seasonal fluctuation of the meiobenthic fauna community around the coastal area of Jeju island, 20 stations were selected and seasonal surveys were conducted. Three-replicate meiobenthic samples were collected from each station in April, July, and November 2017; February, May, August, and November 2018; and February in 2019, in a total of eight months from 2017 to 2019. The total density of meiobenthos at each station ranged from 733 to 2,505 ind. 10 cm^-2. The month in which the highest habitat density appeared in most stations was April 2017 and the month in which the lowest habitat density was seen was February 2019. Nematodes were the most dominant faunal group among the representative 13 meiofaunal groups at all stations. The subdominant groups were benthic harpacticoid copepods and nauplius. The nematode/copepod (N/C) ratio, reflecting the health indices within the ecosystem, varied from 0.02 to 87.40 over the entire season and the average station values ranged from 2.00 to 16.80. The lowest N/C ratio value was found in April 2017 (0.02) and the highest N/C ratio was found at Station 11 in February 2019, which was 87.40, indicating the highest level of pollution. Seasonal and regional meiobenthos community structure similarity was divided into three groups through group analysis and multi-dimensional scaling (MDS) analysis, which showed that the meiobenthos community structure was affected by seasonal variations, rather than by regional differences.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.217-225
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• 1998

This study was performed to compare the effects of a fish cage on the structure of meiobenthic communities at two locations during May, 1996. The number of meiofaunal taxa at the existing cage site and control site was 15 and 26, respectively. Nematoda was the most dominant group of meiobenthos. Nematoda and Sarcomastigophora comprised more than $90\%$ of total meiofauna at both sites. The total density of control site was 7,702 inds./$10\;cm^{2}$ which is 10 times more than that of fish cage site. The density was highest in the upper 1 cm and decreased with sediment depth. The nematodes/harpacticoid copepods ratio as an index of pollution monitoring for benthic ecosystem at fish cage site was two times higher than at control site. Kinorhyncha known to be sensitive to pollution stress was not found at fish cage site.

• 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.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.609-618
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• 2014

We have been studied for geographic distribution, dominance and inhabitation characteristics of marine algal species at intertidal zones of Geojin in the northern part of east coast of Korea, Jukbyeon in the middle part and Gampo in the southern part in May and August 2014. For the geographic distribution, the three areas (Geojin, Jukbyeon and Gampo) were a characteristic of the temperate region. Geojin dominated with Ulva pertusa and Chaetomorpha moniligera, Jukbyeon dominated with C. moniligera and Chondria crassicaulis, Gampo dominated with Sargassum thunbergii, U. pertusa and Ectocarpus species. C/P, R/P and (R+C)/P, which can represent the marine algal flora, were 0.85, 2.10, 2.94 in Geojin, 0.58, 3.15, 3.73 in Jukbyeon and 0.80, 3.91, 4.71 in Gampo. As a result of cluster analysis, Those regions were divided in two groups, which were a group A of Geojin and group B of Jukbyeon and Gampo. This result was well matched with Jukbyeon and Gampo shared their temperate region character in the geographic distribution study.

• Korean Journal of Ecology and Environment
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• v.37 no.1 s.106
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• pp.87-95
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• 2004

Community dynamics of benthic macroinvertebrates in response to natural disturbances (flooding and water temperature) were investigated in the Suyong and Soktae Streams in Busan from October 1997 to September 1998. Oigochaeta and Chironomus, organic polluted indicators, were dominant and various taxa were observed at the study sites. The density and biomass of two dominant taxa increased in warm months while the indicators were washed away in the flooding season. From October to February when the water temperature was less than $15^{\circ}C$, Oligochaeta appeared to be dominant at the Soktae Stream. In contrast various taxa were collected at the Suyong stream. The densities of Oligochaeta and Chironomus increased at the Soktae and the Suyong streams in March. Due to the big flooding in April, the density of dominant taxa decreased abruptly. The community structure showed differences patterns in the flooding season at two streams from June to August. In the Soktae stream, the density increased in August. The reverse patterns were observed in the Suyong stream, washing out in June followed by slow recovery of densities in the fellowing months. Density and biomass showed relatively higher correlations in most taxa. CCA (Canonocial Correspondence Analysis) showed that taxa was different response to different environmental factors.

• Ocean and Polar Research
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• v.35 no.4
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• pp.323-349
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• 2013

The mud shrimp Upogebia major (Upogebiidae: Decapoda: Crustacea) is a common species on muddy and sandy mud tidal flats in the west coast of Korea. They reside in Y-shaped burrows that can extend up to more than 2 meters below the sediment surface. They feed on suspended detritus carried into their burrow by the beating of their pleopods and captured by their hairy first two pairs of thoracic legs. Mud shrimp burrows provide a habitat for a variety of small organisms such as crabs, shrimps, polychaetes, and mollusks. Ovigerous females are observed from December to May. Females deposit eggs only once per breeding season. They start hatching in March and the pelagic larvae of first zoea appear in March and April, followed by benthic settlement in May. Growth over the first year is rapid, and females deposit their first eggs in the third breeding season, 31 months after their settlement. Adult shrimps live for 4~5 years. Depth of the burrow increases with body length. The deep burrows provide refuge from predators and physical stress, allowing the shrimps to survive for a long time. The mud shrimps supply oxygen-rich water to their deep burrows, and exert a great influence on the structure and metabolism of the tidal flat benthic community. However, recently this type of mud shrimp has posed a serious threat to the Korean clam industry along the west coast of Korea. The extensive burrowing shrimp populations suddenly invaded the tidal flats from 2010 where the clams (Ruditapes philippinarum) are raised. As a consequence, clam production has decreased by about 10% over the past three years in some Korean clam beds. Therefore, the objective of this study is to review the biology of this mud shrimp in order to seek solutions to control the burrowing of these shrimps.

• Korean Journal of Environmental Biology
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• v.23 no.3 s.59
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• pp.250-256
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• 2005

A benthic faunal survey of the Hangang Estuary located in the northwestern part of South Korea was performed in October 2004. A total of 11 species identified, which were comprised of two species of molluscs bivalves (Limnoperna fortunei and Corbicula felnouilliana) in two families, two species of annelids polychaetes (Neanthes japonica and Nephtys caeca) in two families, and seven species of decapods (Palaemon carinicauda, P. annandalei, P. modestus, Ilyoplax deschampsi, Eriocheir sinensis, Eriocheir leptognathus and Sesarma dehaani) in four families. Four of the 11 species in six families, Limnoperna fortunei, Neanthes japonica, Nephtys caeca and Palaemon modestus, were newly found in this study area. Eleven species were presently listed with brief ecological remarks.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.659-672
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• 1994

Four simple plotting techniques using the distribution of individuals among species were applied and the results discussed to evaluate the methods for detecting organic pollution-induced perturbation in marine benthic communities in Chinhae Bay, Korea: Rarefaction method, Abundance-Biomass Comparison method, Log-Normal Distribution method and Rank-Frequency Diagram method. Their distribution curves offered more information on the community structure than other frequently used diversity indices and distinguished clear evidence of an effect of environmental pollution with gradient. However, the Abundance-Biomass Comparison method could not be considered applicable due to the presence of larger slowly growing K-strategists in a polluted area of the inner Chinhae Bay, Korea.

• 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.